From my recent diary

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Sun Dec 21

Clear sky again! I comet hunted two consecutive days at predawn, and as a result this was the 8th hunting session this month. It is unusual to comet search so many times in December in my city, since rainy and/or snowy weather prevails in this season in the Japan Sea side area. It was warm for December, and I spent one hour and fifty minutes on the session.

Though I have been very busy this month due to administrative work as a snow scientist in addition to a management work of the Experimental Station, I continue to comet hunt as it is a part of my life that promotes my health.

This predawn I started searching from Hercules, because I swept up to the constellation on the previous day, and the region was far from the crescent moon, i.e. dark. The first DSO I identified was M13 but I could not observe NGC6207, some 0.5 degrees NNE of M13. After I passed M13, I retuned to it to confirm NGC6207; it was too faint to spot during the hunting session under the low altitude and the moon light, but I could observe it with ease when I intended to do.

The path of the ISS at my city.
Sunday, 21 December, 2008
Leaves shadow          05:26:10
Maximum altitude       05:27:10
Drops below 10 altitude  05:30:05

At 5:30a.m. when I stopped sweeping the sky for a moment to observe C/2007 N3 Lulin, I saw a dazzling satellite at a low altitude in NE. It must be the International Space Station (ISS). The ISS approached Vega and I trained my comet seeker at the satellite. The shape of a pair of big solar panels was prominent at a magnification of only 68x! I wanted to change the eyepiece from the Planocular 30 mm to the Ethos 13 mm for better view, and I picked up the Ethos. I looked up the NE again, but the ISS had hidden under the horizon.

C/2007 N3 was located only 9f SW of Beta Scorpii and was easy to observe. It looked 9th magnitude or brighter by intuition; Syogo Utsunomiya reported the magnitude of the comet was 8.0 yesterday.

I hope I could enjoy another clear sky this month.

Thu Dec 4

The sky has been crystal clear for three consecutive predawns since Tuesday. On Tuesday I searched mainly Crater and the western part of Corvus, on Wednesday the eastern part of Corvus and western Virgo, and today eastern Virgo.

At every predawn many galaxies including some globular clusters crossed the field of view: the total number of them were 29, 39, and 29, respectively. Most of the deep sky objects (DSO) were 11 to 13th magnitude. Among three days today was the busiest to identify those DSO, since 22 out of 29 DSO were observed for the first 40 minutes during the 1 hour and 45 minutes searching session. It implied that my comet seeker went out of the gspace windowh where you can observe quite a few of galaxies without being disturbed by dark interstellar material in our Milky Way during the last one hour of the session.

In the hectic time, after a confirmation of a galaxy less than one degree of the telescope motion led to another galaxy for identification. If there was single galaxy or two in the field of view, I could check it using the NGC Vector. However, it often happened that several galaxies could be seen in the same field of view (one of them might not be a galaxy but a new comet!), I had to identify them by the Uranometria 2000, because the digital setting circles cannot distinguish close galaxies due to lack of spatial resolution.

Seven of the brightest galaxies in this photo were observed in the one field of view (1.3 degrees) on Wednesday in Virgo. The brightest galaxy on the right is NGC4261.
The image is 60f wide.
The Digitized Sky Survey copyright © 1994

The maximum number of galaxies that I observed in the same field of view during three days of the session was 7 (the photo above). I believe this is the record high of my comet hunting activity.

It is fun to check DSO, but confirming hosts of them for three consecutive days was somewhat tedious.

Thu Nov 27

Three weeks have passed since I comet hunted last, because winter type pressure pattern cased nasty weather that kept me from observation. Ironically, the sky was clear just before and after the full moon this month when I do not comet search. Actually, this happens frequently!

This time, I believed the forecast and went to bed at 8p.m. at the previous night. At that time the sky was crystal clear. I wake up before midnight that meant the sky was still clear and actually so. My body sensor seems to be sensitive to the fine weather, and in fact it often wakes me up. But it was too early, and I went to bed again. At 2a.m. I roused naturally again. It was a bit early, however, I decided to go comet hunting.

Some 20 minutes drive led me to my favorite observing site. Surprisingly, at 2:40a.m., I heard the noise of machine from far away that must be construction of the road. It was no surprise if you were in urban area, but I was here in rural area. We have so much snow in this region, and the construction firm wants to complete the work before winter. My mind was not very calm due to the noise, while the sky was superb! I could observe the counter glow.

Just after the start of the session, I noticed the star image was somewhat blurred. Very thin cloud began to spread over the sky. This situation got worse as time went, and finally over the 80% of the sky was hidden by the cloud that lasted for around an hour. I was forced to aim at my comet seeker at the gaps of the cloud; NE, SW, and low altitude in the south.

NGC3637 (left) and 3636 (right) with 6.6 magnitude star in Crater.
The image is 15f wide.
The Digitized Sky Survey copyright © 1994

Suddenly, at 4:40a.m., starry sky began to spread and the condition became perfect. I enjoyed the hunting to the full after that, since I identified many galaxies unexpectedly in the constellation of Crater. The most impressive one was NGC3637 and 3636 that are located at 3f NE and 1.7f NW of 6.6 magnitude star: GSC 5511:1183 (11h 20m 31.28s, -10?17f40.5h). Both the galaxies are 12th magnitude. Other than those I identified a dozen of them, most are 11 and 12th magnitude. I remembered there are hosts of galaxies in the area in the result.

After I got home I wondered how far those galaxies are. It is easy to investigate the distance since the recessional velocity of galaxies is listed in some web pages: e.g. you can search it at the following page.
You can estimate the distance dividing the retrieval velocity by the Hubblefs constant (=71 (km/s)/Mpc). gMpch means Mega parsec that is equivalent to 3.26 light-years. The farthest galaxy that I caught this predawn was NGC3660. The recessional velocity is 5040 (km/s)/Mpc that indicates the distance is 230 million light-years. Most of the galaxies I observed were 70 to 80 million light-years. How interesting and how easy! Nowadays, you can search and have a look at NGC catalog or the other so many catalogs with the Internet.

Sun Nov 2

I wake up before 3a.m. The sky was apparently darker than last dusk since the light pollution was mitigated. Even so, light pollution strongly affected the observation. The most light polluted direction with respect to the intensity was the NE, my town, around 20 km away only 70,000 of population, while the light pollution spread most widely in the SE, the direction of Tokyo area: the observing site was 50 km away from Maebashi and Takasaki area with population of 700,000, the northern edge of the Metropolitan area. The center of Tokyo is 150 km away from the site. Light pollution of Nagano and Joetsu, both are some 50 km away, were also eminent.

Before starting the hunting session, I observed C/2006 OF2 Broughton. This comet was bright with a 2f ?long tail and easy to see. I also tried to observe 17P Holmes but could not detect.

After that I challenged Barnardfs Loop with unaided eye using H-beta filter. Actually, I observed this object some weeks ago in front of my house. It was observable with direct vision and easy with averted vision, and I also confirmed there was a nebula-like-object in the south of Zeta Orionis. With 4x22 mm binocular both of them were much clearer. I also saw a nebula in Auriga using H-beta filter that must be IC405, though I did not confirmed the position with the atlas.

I began to comet hunting from M105, and was determined to identify so many galaxies. Zodiacal light glowed as bright as light pollution of Tokyo area. This gnatural light pollutionh reduced the limiting magnitude by one or more. The comet seeker swept from Leo to Virgo and Coma Berenices. I had been busy identifying the galaxies using the NGC Max. At 5:00a.m. a quarter after the beginning of the twilight I saw 6 galaxies in one field. I remembered this group of galaxy. It is a part of Markarianfs Chain that I mentioned in the Diary of 2006. As a result I detected 47 galaxies during one and half hours of session. But this is not record high: I have ever identified 70 galaxies in one session!

Part of Markarianfs Chain that I observed in Nov 2006. Galaxy at the center is M86. This image is 1 degree wide.
The Digitized Sky Survey copyright © 1994

Last dusk, I observed the counter glow and during the predawn session I saw zodiacal light stretched up to 70 degrees before the start of the twilight. Frost was formed on the light shroud, secondary cage, mirror box, and my down jacket, but it did not bother me. It was satisfactory night.

Sat Nov 1

It was raining before noon, but both the forecast and the satellite image implied the recovery of the weather. I headed for the best observing site. As my car approached the site, I noticed that some of the mountain tops near the site were covered with the cloud. Even so, I believed the clear sky at the observing point and continued to drive.

I arrived at the site just after the sunset. Soon after the arrival, the crescent moon and Venus welcomed me, and the cloud began to dissipate. Beautiful dusk!

Tiny planetary nebula in Hercules, NGC6058. The image is 10' wide.
The Digitized Sky Survey copyright ©1994

I started comet searching from NW, mainly Bootes and Hercules, and identified NGC6058, M94, and M13 with NGC6207. NGC6058 is a tiny planetary nebula, and in many cases you tend to overlook such a small one since you cannot distinguish it from a star. This time I could since the nebula was at high altitude, however, I missed NGC6210, brighter planetary nebula in the same constellation, Hercules: it was only 15 degrees above horizon. After completed the session I confirmed how NGC6210 looked: the stars in the field were swelled due to scintillation that had the same size with the nebula. For several seconds of observation I could tell NGC6210 from the stars because the latter twinkled (exactly, the shape varied with time) while the former did not.

Interrupting the session for a few minutes, I observed C/2008 A1 McNaught that had a 2f-long tail and was bright. After the session, I looked at 6P dfArrest, 205P Giacobini, and C/2006 W3 Christensen. 6P looked very faint because of light pollution of Tokyo Metropolitan Area. Lumicon Comet filter was very effective for this comet than the light pollution filters.

As time went, the sky became darker and superb! I must say the sky was as excellent as that in Hawaii in my impression. I tried to observe California Nebula using H-Beta filter with naked eye. It was easy! I could observe the nebula with my single eye using the filter, and could recognize that it has elongated shape with averted vision!

With averted vision I identified M33 that I used to look at it with direct vision in my boyhood. Maybe, my eyes deteriorate due to aging. To measure the naked eyes limiting magnitude I observed stars with averted vision near the foot of Pegasus without prior knowledge, and then confirmed the existence of them with a binocular. I identified the two stars in my house:

T 2229:1549:1
PPM 114881
SAO 90833
HD 216285
RA: 22h 51m 26.670s
Dec: +26
º23' 27.80"
Mag(v): 6.95
B-V: +0.249

T 2246:1707:1
PPM 114924
SAO 90859
HD 216586
RA: 22h 53m 48.770s
Dec: +28
º37' 33.50"
Mag(v): 7.38
B-V: +1.155

Could I see a 7.4 magnitude star at the site where the altitude is 800m? Even in Hawaii (2800m) naked eyes limiting magnitude was 7.5 to 8.0. But this must be true. Body condition must be worse during the travel than usual.

I had an urge to stay up longer to enjoy splendid sky, but I went to bed at 10p.m. in my car for the predawn session.
(Diary at Sunday predawn will be posted in a few days)

Oct 20 Mon

I began to comet search at 3:10a.m. from gamma Leo under the bright moon light. Many dark galaxies are around this region, but I could not detect any of them because of moon light.

Orionids was its peak this morning. However, I did not observe meteor at all both by naked eyes and via comet seeker. I observed a host of Orionids last year.

This predawn it was monotonous comet hunting session, but you should be cautious all the time. As someone said, gThe big one may be waiting for your discovery out thereh.

Oct 18 Sat

The sky has been clear since Monday. I enjoyed observing Jupiter on Wednesday and Thursday, as seeing was excellent for my city (rating 7/10) and the moon was full on Wednesday, i.e. I do not comet hunt.

On Wednesday from 6:00p.m. to 7:30p.m. I observed Jupiter with my 30 cm telescope, Hawaii telescope. I observed with single eye and after that I used a binoviewer. Apparently the latter offered better view of the planet. I could observe a structure in the Great Red Spot, i.e. vortex, for the first time!

At Thursday dusk I employed my 46 cm comet seeker in addition to the Hawaii telescope. Evidently, the performance of the 46 cm was superior to the Hawaii under such good seeing. Sometimes I recognized many white spots and details of the belts. I aimed the 46 cm at Altair and tried to check the diffraction ring, and I saw it for the first time with the scope.

On both the days, at 9:00p.m. seeing turned to worse that I could recognized with naked eyes; the stars were twinkling with high frequency.
Scintillation was bad as usual on Friday and Saturday. Seeing in my area is very changeable and we seldom encounter excellent one. However, it is not a serious problem for visual comet hunting.

<Comet hunting>
Apart from Jupiter, I conducted comet hunting on Saturday that was the 7th session this month. Before the session, I observed C/2008 A1 McNaught for the first time at 6:10p.m. It looked very faint and was the limit of the 46 cm because of twilight, light pollution and low altitude (15 degrees). I made a memo on the appearance of the comet, and I peered into the eyepiece again at 6:13p.m. Surprisingly, the comet was much brighter, and I felt I would never overlook the image during the searching session! Brighter than 9th magnitude.

I did not know the reason for rapid change in appearance. The comet might be covered by thin cloud. I tried to observe the comet at 6:55p.m. again, but could not see it due to lower altitude (6 degrees). Finally, by applying the light pollution filter I recognized the comet. I do not like to use the filter, since it swells the star image that is uncomfortable. Even so, I sometimes apply the filter depending on the condition.

This time I overlooked M107 that was in the area where I swept, because the overlapping of the telescope field was not enough. The observation of C/2008 A1 McNaught and the overlook of M107 was a lesson: it is not easy to spot a new comet if it would be within your search area.

Thu Oct 2 to Fir Oct 3

Excellent transparency! The forecast said it would be clear throughout the night, and I decided to go comet hunting to the best observing site, one hour drive from my home.

At the time of the twilight end, I was disappointed to see the light polluted bright sky. The impression in Hawaii was still in my mind, and the gap between Hawaii and usual site was so big. Anyway, I started comet searching and spent one hour and a quarter. During the session I tried to observe 6P dfArrest that looked bright in Mauna Kea, but could not look at the comet since it was hidden by the woods.

The sky got dark as time went, and I tried to confirm the impression in Mauna Kea in comparison with the usual site. For instance, I confirmed that the detail of the Veil nebula looked better with 46 cm here than with 30 cm in Hawaii, but the image seemed crystal clear and distinct in Hawaii that gave me strong impression in Hawaii.

After four and half hours sleep in my car, I conducted predawn comet hunting session. The major search area was Leo. I identified 16 galaxies. Seven out of 16 were detected during the twilight; NGC3607 (9.9), 3608 (10.8), 3626 (11.0), 3344 (9.9), 2968 (11.3), 2964 (11.7), and 3245 (10.8). The parenthesis is the magnitude displayed by the NGC Max. The last one, NGC3245 was identified some 20 min after the start of the twilight.

Transparency was excellent but seeing was extremely bad. I guessed this terrible seeing degraded the image of the deep sky objects. However, with the help of outstanding transparency, zodiacal light was bright and that crossed the winter Milky Way. The former was somewhat obstructive for the hunting session, but I felt the depth of the universe from the scenery that I enjoy every year in this season.

Click to enlarge.
Depth of the universe: a cross of the solar system and our galaxy.

Tue Sep 30

Last week I went to Hawaii for star gazing with my friend, and utterly satisfied with the dark sky!
It is the place where the Earth and the Cosmos contact. For the detail please click here.

Tue Sep 9 to Thu Sep 11

It has been nation wide clear sky for three consecutive nights, and I conducted satisfactory comet hunting sessions for three predawn. It was not only me who did, of course: Koichi Itagaki and Hiroshi Kaneda spotted a possible new comet on Sep 10 UT that turned out to be D/1896 R2 (Giacbini). It is great work to re-discover this lost comet that was observed last in 1897! Their discovery also encourages comet hunters to show it is still possible to find a new comet.

For me the most interesting session of the three nights was that of September 11th. I started from M78 in Orion at 2:45 a.m. and spotted a comet like object at 3:25 a.m. I could not identify it using the NGC Max digital setting circles! I opened the Uranometria 2000.0, and I found a large diffused  nebula was there. However, I still doubted if the object might be a new comet since the nebula in the Uranometria has several degrees in length. The object was north of the 10th magnitude star, GSC 709:857, 05h31m27.98s, +12deg 09f 10.5h, with a diameter of 1f to 2f. I made a quick sketch and confirmed the motion at 4:00 a.m.: no motion. What a relief with a little disappointment!

After one month of patience, i.e. cloudy and rainy nights, I really enjoyed the hunting sessions.

A new comet? The star at the center with a nebular ti the north (up) is GSC 709:857, 05h31m27.98s, +12deg 09f 10.5h. The width of the image is 15'.
The Digitized Sky Survey copyright ©1994

Another story: My compact 30 cm reflector has completed. It features carrying with a suitcase. I had the first light on September 7th, though cloud cover was 90% of the sky. I aimed Vega first, and the next was Jupiter. I could observe both less than 30 seconds due to cloud but seeing was excellent for this area. Jupiter was jaw dropping! I will report on this telescope someday.

A new 30 cm reflector

Sun Aug 31

Incredibly, bad weather lasts throughout this month, and I comet hunted twice this month as I wrote in the previous dairy.

An article on September issue of the Sky and Telescope magazine entitled gThe Coming Giant Sky Patrolsh reads gDeath of Amateur Astronomy c or New Birth?h

Todayfs sky surveys inflict extensive damage for amateur astronomers, but future surveys will much more.
The first stage of the Pan-STARRS, powerful sky survey project with the limiting magnitude of 22.7, starts the operation at the end of this year atop Haleakala in Hawaii. At present a prototype 1.8 m telescope is about to work, but the final system comprises of the same four telescopes that will start in 2011. Combined aperture is 3.6 m that will discover much more asteroids and comets than any other existing surveys.

The article does not state that the Pan-STARRS is a finish blow but Large Synoptic Survey Telescope, LSST is. The primary mirror is 8.4 m larger than the Subaru telescope at Mauna Kea, Hawaii. As you know you cannot measure the effectiveness of the survey only by the aperture. The larger the aperture is, the narrower the field becomes, generally speaking. This rule does not hold true for LSST. It has 8.4 m F1.18 optical system with the field of view of 3.5 degrees using the world largest camera: 32,000 mega pixel CCD! On top of that the aberration at the edge of the image is less than 0.2h.

LSST will cover the entire sky in three nights, and estimated alert would be 10,000 per night that will be released real time. Amateurs can observe new objects or phenomena referring to the alerts, but I am not fascinated by it. The article concluded that gYes, traditional amateur doors to discovery are closing. But more are opening uph. Probably it is true, but it is still possible to discover a new comet. This might be the last chance.



Sun Aug 10

Last dusk I worked as a volunteer guide of star watching. Around thirty people enjoyed observing Moon and Jupiter with telescopes, and the constellations with naked eyes. Most attendees, including some local people, came from all over the nation to attend the activity of JEN, NGO; they take action to support a depopulated farm village near my city that was damaged by an earthquake in 2005.

It was a hard work for me to operate three telescopes at once as I was an only guide for many audiences, but I was rewarded all the people said gWow!h too see the moon, Albireo and Jupiter. I came home at 10:20 p.m. and went bed soon for the next predawn session.

I wake up at 1:50 a.m. but it was cloudy. I guessed it might be a temporary situation, and watched the sky at 2:30 a.m. again. Clear! The transparency was apparently inferior to last night due to haze.
I stated the session at 3:00 a.m., but few stars were observable through my 46 cm comet seeker at the altitude lower than 20 degrees. The only deep sky object that I identified was M77 in Cetus. If the transparency had been high enough, I could have spotted many galaxies in the area.

Sat Aug 9

This is the first comet hunting session this month. Like last month it has been cloudy especially only at night, even if it was fine in daytime.

Before the start of the session, I tried to observe C/2008J1 Boattini but cloud not see partly due to light pollution. I observed the comet last month with 11th magnitude that looked the limitations to spot during the hunting session. The next target, C/2007 W1 Boattini, was an easy object, but looked fade in comparison with last monthfs observation.

M38 (the upper cluster) and NGC1907.
The Digitized Sky Survey copyright ©1994

At 2:20 a.m. I began to sweep from C/2007 W1 toward the east. I knew there are few comets like objects except M1 in this region. I was impressed by the two major open clusters M45 and Hyades (Melotte 25) passing through the field! Some 30 minutes later a comet like object at a low altitude startled me, but after a second I recognized it as M1. In the constellation of Auriga I encountered the three sparkling open clusters M36, M37, and M38; they looked like old friends whom I had not met for a long time since I have not observed them for several month. NGC1907, a neighbor of M38, is a tiny open cluster that is more impressive than M38 with my 46 cm; M38 is too sparse at 68x.

15P Finlay was within the search area of this session but I did not spot it probably because of the haze at a low altitude and the twilight.

Mon Jul 21

It has been cloudy and I comet hunted only once this month. There were some clear days but I was clouded out at dusk and/or predawn. Even if the sky was gclearh, in some cases transparency was too bad to comet hunt. It seems like that the number of such unsuitable days for comet hunting increased recently.

I have read about transparency in the August issue of the Sky and Telescope magazine. Major cause of haze is aerosol cased by both human activities and natural processes. The former is sulfur oxide (SOx) or nitrogen oxide (NOx) originated from fuel power plant and vehicles that causes photochemical smog leading to spread ill health. The latter is volcanic or forest fire smoke, but in Japan pollen from planted forest sand and yellow sand from Chinese desert should be added. Aerosol also boosts light pollution.

As far as I know, we have never experienced urban ozone here in the Japan Sea Side, since there are no big cities around the area; however, it occurred last year for the first time. Due to spiraling economic growth in China these harmful gases flew from the continent. You cannot say that we, Japanese, are just injured party but at the same time victimizer. Japan import huge amount of products from China and the gases are released under the production processes.

To enjoy clear and dark sky we have to be greenc but what we should do for that?
Anyway, the Japan Meteorology Agency stated that the rainy season seemed to finish on this weekend. Now, we are at midsummer to enjoy stargazing.

Wed Jul 2

Precious clear sky!
It was slightly fogy, and I knew I could avoid it if I had driven twenty minutes to a hill. Unfortunately, I could not afford to do so, because only ten days has passed since the summer solstice and the twilight begins at 2:30 a.m.; I have to get up very early at 0:30 a.m. to go to the hill.

I got up at 1:00 a.m. and completed setting up my comet seeker in front of my house at 1:30 a.m. I had to fix two stars to set in the NGC Sky Vector. The first star was Fomalhaut, Alpha Piscis Austrini, and the second was Alpheratz, Alpha Andromedae. When the telescope was aimed at Alpheratz I noticed a comet like image near the star! At the next moment I realized that the star was not Alpheratz but Beta Andromedae, as the NGC Sky Vector indicated the warning for the wrong alignment. Anyway, I spotted a possible comet!

My heart began to beat faster and faster. I changed eyepiece from Planocular 30 mm (made in German with apparent field of view of 88 degrees) to Ethos 13 mm, but apparently the image was comet like! I opened the Sky Altus 2000c I found NGC404 is just near Beta Andromedae. I must have observed this object last year or so, nevertheless, I took it for a possible comet.

NGC404 (center) and
Beta Andromedae
The Digitized Sky Survey copyright ©1994

Before the start of the comet hunting session, I tried to observe C/2008 J1 Boattini but I could not see the comet at a glance. It must be defused, but I did not check carefully to identify it since I felt that it was waste of time; I am not a comet observer but a comet hunter. At least I can say that I could not spot C/2008 J1 if it would have been a new comet.

I observed several meteors through my comet seeker and one by naked eyes during the session in addition to NGC488, 524, and M74 that looked huge in apparent diameter. After the beginning of the twilight I observed 15P Finlay. The comet was some 15 degrees above the horizon but I could observe it. Since the image was very faint it was impossible to discover this comet during the comet hunting session. I enjoyed stimulating session.

Mon Jun 23

So far I have comet hunted three nights this month. The other day the Japan Meteorology Agency declared the rainy season started in my prefecture, and I cannot expect clear sky for about one month from now on.

Under such nasty weather, I want to go star watching to splendid place, e.g. Hawaii, with a large aperture telescope. I have such a feeling every now and again, especially in winter and the rainy season. Actually, I began to make a 30 cm Dobsonian by wood that can be carried in a suit case and can be handled as a check-in baggage for air travel. I will travel all over the globe with the scope!

However, I was upset to read an article of Mitsunori Tsumura in an astronomical magazine. When he arrived at an air port in Australia, he had to declare all the wood products that he had at the quarantine. His Dobsonianfs rocker box was manufactured by wood, and the officer stated the inspection was required, because there were some wormholes on it. The officer said it would take at least three days, and Tsumura abandoned the rocker box. He bought wood and a saw at DIY shop to build a new rocker box on site.

I inquired Australian embassy in Tokyo if I can take fumigated wood products with certification. The answer was that the final decision would be made by the officer. If you visit Australia you should bring a telescope that does not involve wood material!

Anyway, at least I can fly to Hawaii with the new 30 cm scope, probably this year.

Top ring (small ring), side bearing (large ring, yet divided), and six-point support mirror cell.
This telescope is based on Alan Scottfs 30 cm Dobsonian, and gThe Dobsonian Telescopeh.

Mon Jun 9

It has been nasty weather last month, and I comet hunted only three nights; none of them were preferable conditions due to gauzy clouds. Such clouds not only reduce transparency but also enhance light pollution.
 I arranged my Borg 125ED refractor with Vixen Porta altazimuth that is equipped with the digital setting circles (refer to the diary on January 18) so that I carry them with ease. I manufactured a wood box that can carry the optical tube assembly, the dew shield, the light shield for an eyepiece, and the computer of digital setting circles. The altazimuth mount is protected by polyurethane board that is taped with thin stainless steel adhesive tape. A small camera bag, lower right in the photo, is for small parts; eyepieces, a 2 inch erect prism, and the Quick finder.

Home made wood box, polyurethane protector for the altazimuth, and soft bag for small parts.

I conducted comet hunting at dusk for ten minutes last month using this system. It was handy and easy to operate, while what I do not like is intolerant of wind, and long damping time of vibration especially for high magnification. For these reasons, this system is not suitable for lunar and planetary observation.

After using the 125ED refractor I continued comet searching with my 46 cm comet seeker.
I tried to compare the differences in power between the 46 cm and the 125ED. I identified NGC3377, a galaxy in Leo, with the 46 cm, it was bright and very easy object. Then I aimed at the same galaxy using the 125ED. It was faint and could be barely recognized with this small aperture. The 125ED looked like a finder of the 46 cm in terms of the light gathering power, but the field of view is over six times larger.

I may not the 125ED so often in the future, but fiddling with the scope is enjoyable at cloudy nights.

125ED system in front of the certain; if only I open the certain I can start comet hunting from the room that directed to the southeast. I may not able to set digital setting circles since it is often difficult to fix two stars from the window. Even so, I can measure both vertical and horizontal angular distances between a known star and possible comet using the digital setting circles, if I spot an unknown object.

Sat May 16 to Sun May 17

I attended the 38th Comet Conference in Hiroshima that featured a special guest Mr. Robert McNaught from the Siding Spring Observatory, Australia. I enjoyed the Conference this time; I hosted the Conference last year, and I had been assigned a chairman of the comet hunting session of the Conference many times but not this time.

As a professional scientist I had wondered if McNaught was not obliged to write scientific papers, even though he is a professional astronomer. Actually, he wrote some scientific papers but it does not seem to be his main work. If he is hired as an engineer, he cannot employ the Schmidt camera exclusively for long time. If only I had read the web page of the Siding Spring Observatory, I would have obtained the answer soon, but I did not.

I understood why he can concentrate on the searching activity to listen to his speech: he was hired to search new objects. How affluent the Westerners are! In our country it never happens. Japan is poor in that way. I believe creativity is formed where there is enough scope, which in many cases produces something impressive like a work of art. His job, though it is a part of the Survey Project and done through the electronic displays, is similar to that of an artist, because his discovery is made with hnaked eyesh via the displays applying his strong will to do so. We, amateur comet hunters, want to be the same. The audience was impressed with his speech, because he has such an enthusiasm.

From left to right: Ms.and Mr. McNaught, Murakami, and Ichimura (Discoverer of C/1987 W1 Ichimura)
Note that a bottle of Japanese alcohol "Sake" on the left.

Someone put a question, and he answered.

Q: What is the driving force to continue to search new objects?
A: It's fun!

To hear his answer, we felt his pure nature that endorsed by an amateur spirit, and that drew applause from all the audience!

Yuji Hashimoto in Hiroshima, the Vice Chairman of the Conference, is a visual comet hunter, and he goes comet hunting to suburban area driving a camping car. He said he purchased his camping car for comet hunting. On weekdays, he gets home, eats supper, takes a bath, leaves his house with his camping car in the evening, has a good sleep in the car, and then comet hunts at predawn. He goes to his office from the observing site directly after the daybreak. Enthusiastic!

For me genthusiasmh seems to be a keyword for this Conference, and I was stimulated in that way.

    Nothing great was ever achieved without enthusiasm.

                    Ralph Waldo Emerson
                    U.S. philosopher, poet and essayist, 1803-82

Tue May 6 to Wed May 7

I headed for one of the best observing sites with an altitude of 800 m a.s.l. but I wondered if the road was open: snow might remain in some part of the road. Luckily, I could arrived at the site, however, judging from the existing snow amount near the site I felt I could not have reached the place, if I had tried to visit here a few days earlier.

Before I started to comet hunting, I observed C/2007 W1 Boattini. It was bright and large! Then, I began to comet search from the north of Alpha Gemini, Castor. The reason was simple; light pollution is less in this direction. The first comet like object I identified was NGC2372, a planetary nebula, in Gemini, but I failed to detect brighter planetary nebula NGC2392, Eskimo nebula. This is because the nebula was tiny and very bright, and looked like a star. The other comet like objects I caught were galaxies NGC2672, 2749 (both are 12th magnitude), and 2903.

After the hunting session, I made a sketch of  C/2007 W1, and enjoyed deep sky objects, M51, M101, and M13. The spiral structures in M51 and M101 that are well recognized with averted vision at the observing site near my house were apparent with direct vision, while M13 did not resolved well because of poor seeing.

Unexpected light pollution spoiled the southern sky this evening, and it turned off at around 10 p.m. I guesses it originated from the ski fields that were still open. On Wednesday my colleague told me that it was true. After that, I had a good sleep in my car for three hours and half.

Wed May 7

I wake up at 2 a.m. and noticed that the transparency got worse than yesterday.
Some 200 m apart from my site, I saw a light last evening and it was still on. I though it must be astronomer's one and aimed at my comet seeker before the comet hunting session. The answer was yes! A man operated a reflector about 25 cm in aperture.

I searched the northeast for one hour and a quarter, but the only nebula that I identified was Andromeda Galaxy. Exactly, I observed not only M31 but M32 and M110. I wondered if there might be some galaxies that I could catch in this region, but under this sky condition these could be overlooked.

After the daybreak I visited the man for greeting. He looked in his sixties and said came from Saitama Prefecture, Tokyo area. It takes 3 hours from his house here. He also said that he tried to come here on April 30 but could not because of snow.

Tue Apr 29

Though the forecast predicted clear weather yesterday, it had been cloudy with poor transparency in daytime. I did not expect clear sky at the next predawn, and stayed up late last night. At 10:00 p.m. I checked the sky and noticed that stars were twinkling with good transparency; the different characteristics of air mass had come into my region. I went to bed right away, and set an alarm clock at 1:30 a.m.

I woke up as scheduled, but the sky condition was much poor than I expected. In no time I noticed that it was time for Moon rise. It was already on the horizon but the woods hid it. It took longer than usual to set up the comet seeker due to only 3 hours sleep, i.e. my body did not work well. OK, no need to worry about it because it is national holiday today. I wonder if from where I should start the hunting session: the east or the west of the moon. I decided to begin with the west of the moon, the constellation of Sagittarius, since the moon was there in the previous day and the moon light around the position made it difficult to detect a new comet.

Some deep sky objects (DSO) brighter than 9th magnitude went across the field. If it had not been for the moon light, I could observe 11th magnitude DSO in this region. A globular cluster M22 that resolved up to the center, was impressive with several bright stars; five to 7th magnitude and SW of the cluster in the same field of view. At the next swing of the telescope this cluster crossed the field again, but it looked only dim object due to the moon light without bright stars in the field. As the telescope approached to Moon, the contrast in the field got worse and I decided to shift to the east of  the moon when Jupiter came into the field.

The mask for the moon and the planets observation.
The aperture is 18 cm.

I aimed the comet seeker at M15 and resumed comet seeking when the twilight started, and finished today's session in 30 minutes.
Before taking down the comet seeker, I enjoyed Moon watching using the BinoVue. I manufactured the mask for the moon and the planets observation some years ago that apparently improved the image in most cases in my observing site in spite of reducing the aperture down to 18 cm.

Wed Apr 9

Awesome! This is the most fruitful comet hunting session among the three this month, though there was not a speck of cloud in the sky in all these three predawn sessions. Today it was dry and clear for spring (usually hazy) with little wind. I started with M4, a globular cluster in the constellation of Scorpius, 1.3 degrees west of Antares. The stars in the cluster resolved easily and impressive with 46 cm 68x. The next swing of the scope from an altitude of some 40 degrees to the horizon led me to another globular cluster NGC6144, 0.6 degrees northwest of Antares. This globular cluster also resolved into stars, and the contrast of the cluster and dazzling Antares was vivid.

I had prepared for identifying a host of globular clusters, and as expected I did nearly 40 of them during one hour and fifty minutes of the session. As for open clusters I cannot tell how many of them I caught; for one thing any part of the Milky Way looked like an open cluster due to high light collecting power of my comet seeker, and for another I do not  identify  most open clusters that resolve into stars.

M7, NGC6453, and NGC6444 were in the same field of view with 68x, but each of them has completely different appearance. M7 is the sparsest and occupies large area of the field with many bright stars;
NGC6444 is moderately  condensed and middle sized; NGC6453 is the darkest, smallest, and highly condensed because this is a globular cluster.

M7 (left), NGC6453 (upper right), and NGC6444 (right)
NGC6444 is not distinct in this photo since limiting magnitude of the image is too dark and so many stars are shown. Image is one degree wide.

The Digitized Sky Survey copyright ©1994

Besides star clusters, I have met other sorts of deep sky objects
except galaxies: planetary nebulae, reflection nebulae, and dark nebulae. My space walk has completed at M54 at 4:30 a.m. before my comet seeker reached Jupiter.

Sat Mar 22

To date I  have conducted the comet hunting sessions three times this month, although I got up in the wee hours six times in total; i.e. I could not comet search three predawns in spite of going out of bed. Two overcast and one extremely bad transparency due to yellow sand from the continent dessert prevented me from the hunting.

As I have not yet observed C/2008 C1 Chen-Gao, I tried to observe the comet tonight regardless of the full moon.
At a glance I did not notice the comet at 68x with my 46 cm comet seeker. I peered into the field comparing with the star chart that I printed out, and finally spotted the possible image. I boosted the magnification up to 157 changing the ocular to Ethos 13 mm, and I firmly confirmed the image was the comet. I estimated the comet as the magnitude of 11.0. Under the moonlight like this I had not spotted this comet if I would have made a comet hunting session. In case of a dark night, however, I would never fail to overlook this image.

I also tried to observe 17P Holmes and 46P Wirtanen, but I could not confirmed both the comets because of the moonlight even with 46 cm.

After observing comets I enjoyed Moon and Saturn using the BinoVue (Televue's binoviewer). Most Newtonian telescopes does not achieve focus with binoviewers, and I combine
Bino Vue with the Optical Corrector Assembly (OCA) supplied by the Siebelt Optics. The manufacturer carries various sorts of binoviewers and the attachments. I purchased the "Universal OCA" several years ago. With this model three magnifications of OCA, 1x, 1.5x, and 2x, are available by replacing and/or adding the lens elements, and you can utilize it for both Newtonian reflector and the refractor, though my 46 cm does not focus for 1x.

From left to right: one of the SWA 20 mm 70 degrees eyepiece, BinoVue with another SWA 20 mm, a pair of Pentax XW 10 mm, OCA and two corrector lenses, and a 2" barrel with the filter to attach the 2" filter to OCA.

For planet and moon observation looking at both eyes (applying the binoviewer, not using a binocular telescope) reveals much more details than a single eye in my experience.

I usually enjoy observing the planets or the moon after completing the comet hunting session before the daybreak that means more than 30 minutes from the start of the twilight. Though scintillation in my city is notorious throughout the year,
before sunrise the scintillation seems to be rather stable: even so I have seldom recognized diffraction ring at any apertures of telescopes in my city! This implies poor scintillation does not affects comet hunting seriously, probably because we apply low magnification. If star images are swelled even at a low power you will be disappointed to look into the eyepiece: I have experienced such a situation at dusk but it recoverd in no time with a drop in temperature.

Sun Mar 9

Spring has come! The forecast predicts we will have a couple of fine days this week that never happened in January and February in my area, Japan Sea side. I comet hunted only twice last month, February 5 and 11, and this predawn is the first comet hunting session this month.

NGC6366, Image is 15' wide
NGC5897 on the Diary on February 5, this globular cluster is defused, and tend to overlook under light polluted condition. It looked granular using my 46 cm comet seeker,  but did not resolve into stars shown in this photo.
The Digitized Sky Survey copyright

As planed last night I got up at 2:20 a.m. and headed for the usual observing site where I arrived at 2:55 a.m. At 2:20 a.m. I began to search from M12 positioned at the center of Ophiuchus. I identified some two dozens of deep sky objects, though the transparency of the sky was not good
that often occurs in spring in Japan due to yellow sand from China and pollen. Temperature dropped down to minus 5 degrees in Celsius with a light breeze, but I did not feel chilly now that it is the end of winter, and we are well acclimated to coldness. The deep sky objects I detected included major Messier Objects, M22, M 17, M8 etc., but the most impressive one was NGC6366, a globular cluster in Ohiuchus. The diameter was nearly 10' with low surface brightness, and the total magnitude was difficult to estimate like that of Comet Holmes: about 10th magnitude but 12th by intuition. Neither the Tago and Seki Catalog contain this globular cluster, which implies that it is darker than 11 or 12th magnitude the comet hunters' standard. The Sky Vector displayed it as a 10.0 magnitude object, and the MegaStar says it is 9.5 in magnitude.

Tue Feb 5

It has been snowy or cloudy this year. I got up predawn at least three times last month, but in vain. Fortunately, last dusk I observed 17P/Holmes near Algol, beta Persei, for the first time this year (it was second time!) with 8x50 binocular: that has a diameter of around 1.5 degrees and was elongated. This fine weather trend lasted through the night, and this predawn I could comet hunt for the first time this year with another bonus: I tested unique product, Ethos 13 mm eyepiece.

At 2:30 a.m. I headed for usual observing site, but on my way to the site I noticed a huge cloud appeared in the direction of the site. I decided to get back and set up 46 cm comet seeker near my house. Before the comet hunting session, I aimed the scope at M5, globular cluster, in Ophiuchus. I compared the star image using Ethos 13 mm and Nagler type 4 12 mm. When I first looked into Ethos I felt as if the super wide angle of Ethos brought me into the space. The sharpness of the star image and the contrast around the center of the field looked similar in both oculars, but near the edge Ethos was superior to Nagler in terms of homogeneity. Ethos has opened the new paradigm for visual observation without doubt.

After impressive first light of Ethos I started comet searching, however, cloud began to cover the sky. Ouch! I was overcastted at 3:30 a.m. At 3:45 cloud opened slightly at a low altitude in SE, but I could sweep the area only for 5 minutes: it closed in no time. After a while cloud got thinner and I enjoyed observing Saturn though thin cloud. I repeated such actions but I was not frustrated. I continued hunting on and off aiming the scope here and there, and identified faint galaxies NGC5796 and 5898, and a globular cluster 5897 in Libra that are difficult objects to catch at my usual observing site due to light pollution from the ski fields: the overall sky condition there is much better than near my house but SE is inferior in winter. My comet seeker could resolve dozens of stars in NGC5897! At around 5:40 a.m. about one hour before the sunrise, I caught M8, M28, and M22 at an altitude as low as some 10 degrees. M28 looked like a comet and it might be challenging to identify it without digital setting circles under the twilight and at low altitude. I was satisfied with the session after a long absence.

NGC5897 Image size is 15'x15'
This globular cluster looks defused image and it is difficult to observe under light polluted sky: Seki catalog estimates it 10th magnitude and 7f in diameter while Tago catalog dose 9th and 7f.
The Digitized Sky Survey copyright

Fri Jan 18

On Tuesday I got up four times at predawn believing the forecast that said clear sky prevailed before the daybreak.

The first time, before 2 a.m. it was too early to do comet hunting. Though I set an alarm clock at 3:30 a.m. since the twilight begins at half past five, but I automatically wake up. Overcast!
The second time, at 3 a.m. Spica, Alpha Virginis, and a quadrangle of Corvus were twinkling among a gap of clouds. The gap occupied only small portion of the entire sky, but I expected it would extend in half an hour.
The third time, at 3:30 a.m. the gap had shrunk, unexpectedly, but I still anticipated clear sky in another half hour. Ten minutes past four, the fourth time, unfortunately, dark snow cloud covered whole the sky, especially the east. I checked a radar image using my mobile phone that displayed some snow clouds around my town. Finally, I decided not to comet hunt that predawn.
It was clear after sunrise and it lasted during the day time. There is a time lag between the forecast and the actual weather for a few hours.

OK, it is cloudy or snowy tonight also. I have never comet hunted this month. Even so, I have a lot of things to do. I bought a kit of digital setting circles for the PORTA altazimth mount produced by Vixen.
The kit was supplied by Kokusai Kohki, Kyoto, Japan. This week I began to install the kit: chances are you can discover a bright new comet with a small instrument as Araki (Diary Dec 1, 2007) did in his discovery of IRAS-Araki-Alcok (C/1983 H1), or like an outburst of 17P Holmes.

PORTA with digital setting circles             
14 cm Schmidt Newton with Ethos 13 mm (apparent field of view (AFOV) is 100 degrees)

Early this month I brought a Schmidt Newton (SN), 14cm f 500 mm, which was stored in my parentsf house. I purchased it probably in the late 1980fs, but I seldom used it. I had an idea to employ this scope with Ethos 13 mm eyepiece that I bought this month also. This combination produces a magnification of 38x with a field of view of 2.6 degrees! With PORTA it is compact and easy to handle as a comet seeker.

Another owned scope for PORTA is BORG 125 ED, 12.5 cm f 800 mm. This scope has been used with TA altazimth, but PORTA is superior with respect to portability. With newly bought EWV32 mm eyepiece (Kasai Trading, AFOV 85 degrees) and a 2 inch erect prism this scope has a magnification of 25x and FOV 3.5 degrees. This is also an attractive specification.

BORG 125 ED mounted on PORTA

At first, I thought 14 cm SN has higher light gathering power than that of 12.5 cm, however, it is not. 14 cm SN has rather large secondary mirror of some 5 cm, and the corrector plate seems non-coated. The secondary mirror reduces virtual aperture down to 13 cm and non-coated corrector plate loses additional light from objects: assuming that the reflectivity of the corrector plate is 8% (4% for one side) the equivalent aperture of 14 cm SN is 12.4 cm. I compared both the telescopes viewing a distant pylon with similar magnifications at daytime. At a glance 12.5 cm with the errect prism revealed brighter and sharper images than by 14 cm.
Though 14 cm SN is more compact and light weighted, this instrument probably continues to rest in a storeroom.

Anyway, it takes much more time to complete orchestrating 12.5 cm scope and PORTA with digital setting circles.

Sat Jan 5

A host of  observations on 8P
Tuttle and 17P Holems are made via Japanese comet mailing lists, but about one moth has passed since I observed those comets last. As usual year dull weather prevails at this time of year in my city. Luckily, last dusk fine sky spread for a couple of hours, and I went to out with my 8x50 binocular to observe the comets. 17P was apparent with naked eyes, and I could even recognize that the comet was elongated with an apparent diameter of some 1 degree. To the contrary 8P was in the light polluted area, mainly caused by sky fields, and could not be observed by naked eyes. With the binocular 17P was large but defused and  faint, while 8P was bright with high degree of concentration.

I went to bed early last night expecting cloudless sky this predawn. I woke at 3:30 a.m. but heavy cloud covered all the sky.
During the New Year holidays I was in my parents house and brought back a telescope that I purchased in the late 1980's. I have a plan to use this telescope as a comet seeker. The scope is light weight and has high portability. I will introduce it in the future on this page.

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