From my recent diary

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Monday, December 21

It has been warm for December till last Wednesday, but suddenly temperature dropped and we had heavy snowfall. There was no snow on Thursday but the snow depth reached over 1 meter on Sunday. Now, the depth is kept over 1 meter.

Today, I saw a man snow removing in a traditional and tricky way.

The snow block he removed was slipping down the wood trough that was set for this purpose.

At the end of the trough, snow block crossed the road and jumped into the flume.

Having the traditional hat and mantle he looked like a superman!

I have comet hunted once this month, and that may be the last one this year. I will go on a trip to Australia this year-end and new-year holiday, and will stay at Richard Brownfs house in NSW. He is a comet hunter and owns a 22h reflector.

I move from the snowy place to the summer world, which may be hard but it is exciting to observe the southern sky for the first time!

Sunday, December 13

I had been so busy for these three weeks that I could not afford to update my web page. Even worse, I worked too hard and am suffering from back ache, though it is getting better. I should take care because I am not young.

Last month I conducted comet hunting seven times thanks to the good weather.
On Sunday November 22 when transparence was excellent, I mainly searched in the constellation of Virgo, and identified 45 galaxies.

However, Tuesday November 24 was the most impressive session this year. My body sensors woke me up at 2:30a.m. well before the time when the alarm clock rang. I was drove to the observing site. The sky was superb with bright the winter Milky Way!

I searched Hydra and Crater where the effect of the zodiacal light is less and dark. The first galaxy that I detected was NGC2992 with the companion NGC2993, both are the 12th magnitude. At 4:07a.m. 47 minutes from the start of the session, a faint object came into the field of view. I tried to identify it using the NGC Sky Vector, but no suitable candidate appeared.

ESO 501-102
Image is 15' wide.
RA: 10h 50m 58.4s; Dec: -23 39' 30"; Mag: 13.3 (P); Size: 1.4'x1.1'
I acknowledge the usage of the HyperLeda database (

I opened the Uranometria 2000.0 and I noticed a galaxy E501-12 is on the Atlas near the position of the suspicious object. I though that the object marked on the Atlas must be very dark since it belonged to European Southern Observatory Catalog and that it would not be observable using my comet-seeker. The object was a possible new comet!

I felt my heart beating. I changed the eyepiece from Planocular 30 mm 68x to Ethos 13 mm 157x, but still the image was comet like. I carefully compared the position with the Atlas and it turned out that the object was E501-12. I learned that under the excellent sky condition I could observe very dark galaxy.
That was a disappointment, but I enjoyed a thrill. The galaxy was mistakenly described as E501-12 in the Uranometria: the correct name is E501-102 (E=ESO).

Seven minutes later, a bright meteor crossed the FOV! It was third magnitude or brighter and the brightest I have ever seen through the telescope. At the next moment, a galaxy, NGC3621, and the meteor train appeared in the same FOV that lasted some 30 second! It was as if the heaven had celebrated my false discovery.

I encountered another faint galaxy that could not be identified by the NGC Sky Vector. It turned out to be M3-28-27 (MCG-3-28-27) using the Uranometria. I spent 2 hours and a quarter in totalsand it was a fruitful session.

Sunday, November 15

At this predawn the sky condition was the best in this fall! The winter Milky Way arched brightly over the sky. However, the clear sky seemed to be a local phenomenon because I saw flash of lightning many times during the comet hunting session. Indeed, the meteorological radar image showed thunder storms with high rain fall intensity near my city.

A solid circle indicates Tohkamachi where I live.
The map is 600km wide.

At 3:35a.m., before the start of the session I observed C/2007 Q3 Siding Spring. The comet was approaching to NGC4216, very elongated 11th magnitude galaxy, and I noticed both objects at first glance. I knew there were many galaxies in the field of view but could not recognize except for NGC4216 due to low altitude.

I started sweeping from Regulus, Alpha Leonid, and in 10 minutes M104 came into the field of view. The galaxy was only 5 degrees above the horizon, nonetheless, the dark lane in the nebula was easily visible!

At 4:40a.m. I watched C/2007 Q3 again, and this time I noticed six galaxies were in the same FOV! What if I had encountered the situation incidentally? Could I identify the comet? Probably, yes. I would check all the galaxies using the Uranometria 2000, though it would take some time. You have to be very careful for identification of doubtful objects.

C/2007 Q3 Siding Spring with galaxies. The ciecle represents FOV: 1.3 degrees.
(c)MegaStar Ver.5.

I resumed the session. M65 and M66 were shining with pride and NGC3628 looked like a huge elongated cloud. A minute later actual cloud covered more than half of the sky before 5a.m. It was a negligible incident. I had quality time.

Sunday, November 8

The alarm clock rang at 3 a.m. Though I went to bed at 8:50 p.m. last night, I felt sleepy and managed to get out of the bed at 3:10 a.m. The sky was clear with partial thin cloud.

During the session, the amount of cloud increased and I was compelled to change the search area four times.

1) I started comet hunting at 3:50 a.m. from M65 that looked fairly faint due to the moonlight and the low altitude. In 10 minutes thin cloud covered the region and I was forced to train my comet-seeker at the other direction.

2) I turned to the northeast, but a matter of minutes cloud hid the area.

3) The south was the only cloudless direction, and I resumed from M41. Beautiful! Even under the bright moonlight that reduced contrast in the field of view (FOV), I felt a great joy with quite a few of stars in the winter Milky Way. Oddly, the background in the FOV got darker and the contrast was enhanced as my comet-seeker approached near the horizon: the angular distance between the moon and the FOV increased with the downward motion of my telescope. It was completely opposite what I have experienced during usual sessions. The moon was as high as near the zenith that made the effect more prominent than usual moon light night.
I wondered when it was and what I was doing, because the twilight like situation continued long time because of the moonlight and something was different with the hunting session. In other words the atmosphere was unreal.
The moon was in thin cloud and had a halo, when I looked up her. After around 30 minutes the area was covered with the cloud.

4) The comet-seeker was aimed at the southeast, but in 10 minutes cloud stretched this area.

5) Again, I observed M65 that looked much brighter than I saw at the beginning of the session at 3:50 a.m. I also noticed both NGC3628 that was not recognized at 3:50 a.m. and M66. I resumed the session from here and finished at 5:05 when thin cloud covered the entire sky. Then, I enjoyed moon watching through thin cloud using a binoviewer.

The motion of the cloud was slow and the moonlight shed light on graceful shaped thin cloud fantastically. The sky near the horizon offered darker background in the FOV due to weaker moonlight than higher altitude. The lunar played an occult role for this session and I enjoyed it.

Sunday, October 25

There appeared many fine days for a week and my body moved with the weather. I overdid comet hunting and a bit tired.

Nonetheless, I have never felt relaxed during the comet hunting sessions this month. Moonlight, light pollution (at dusk) and cloud interrupted me. Today, the eighth session this month, transparence was moderate at higher altitude, but poor at the lower part of the sky. Even so, I expected satisfactory hunting session this predawn.

NGC3115, Spindle galaxy
The image size is 10'.
The Digitized Sky Survey copyright (c) 1994

I started with Alphard, Alpha Hydrae. The first DSO that came into the field of view was NGC3115, Spindle galaxy. Impressive! Soon after that, incredibly, cloud began to spread and it hid the eastern sky. I was forced to search the other part of the sky, but every time I aimed my comet-seeker at a certain part of the sky, cloud covered there.

I searched from place to place patiently, and often looked up the sky. The Orionid was still active and I observed a few of them. Zodiacal light was bright that rose nearly vertical to the horizon.

The twilight proceeded and M84 in Virgo disappeared from the field of view while I left my eye from the eyepiece to take notes. The northern sky was still dark, and I continued hunting. NGC4589, the 11th magnitude galaxy, was the last DSO I observed this predawn at 4:55a.m., 20 minutes after the start of the twilight.

Tuesday October 13

Clear sky! Actually, I did not expect fine weather as the forecast has been off the mark many times, but I got up before 3 a.m. and it was rewarded. The waning moon was bright, but the transparence was good.

I started searching from the constellation of Leo, because many comets have been discovered there in October, as Tsutomu Seki pointed out. Nevertheless, I trained to my comet-seeker to the northeast after 30 minutes, since in Leo even the Messier Objects, which were at low altitude, could not be observable due to moonlight: the moon was in Cancer.

I came across many galaxies in Ursa Major and Canes Venatici: NGC3941, 3675, 4151, 4143, 4138, 4490, 4449 and M94. It was pleasure to observe 10 to 11th magnitude objects under the moonlight.

The session was completed at 4:55 a.m. when the hind legs of Leo and Venus rose above horizon.

Monday October 12 (National holiday)

Yesterday, as the forecast predicted clear sky throughout the night, I headed for the best observing site at 5 p.m. On the way to the site, raindrops hit the windshield of my car! Incredible!

I checked the weather information using my mobile phone, and it turned out that the prediction was modified from clear sky to cloudy and rainy. I decided to get back to my house.

The forecast released at 5 p.m. Oct. 11 said it would be cloudy during the night (above), though in the morning the prediction stated the clear sky would continue at night. Rainy trend is not displayed in the chart above but the announcement in the text read there would be shower in some places.

As predicted it has been clear sky in daytime today, but again I was clouded out at dusk: the forecast was off the mark. I comet hunted only once this month, and the duration was merely 10 minutes due to cloud.

Tuesday, September 29

I have comet hunted 7 times this month including the two nights spending in my car; I comet searched both at dusk and predawn. The most satisfactory one was conducted at predawn on Monday September 21. I could spot NGC2359 (the Duck Nebula) in Canis Major and also notice the planetary nebula in M46, NGC2438, at an altitude of as low as 15 degrees. The other impressive object was the Rosette Nebula that came across the field of my comet-seeker under the very dark background.

The planetary nebula NGC2438 (upper left) in M46
The image is 15f wide.
The Digitized Sky Survey copyright (c) 1994

Since then, the weather forecast was revised downward many times. I got up four predawns with the hope of clear sky, nevertheless, I could search the sky only once; at predawn on Thursday September 24 when the sky was very hazy.

Autumn is the best season for comet hunting here in my city, and I am anticipating to meeting with my love, the deep sky objects under the clear sky!

Wednesday September 9

The twilight end: 7:30 p.m. The moonrise: 8:00 p.m.
I was thinking, gIt is possible to comet hunt for about one hour, if I start at a quarter past sevenh. The problem was the weather.

When I finished the work at 5:40 p.m., the sky began to clear, though it has been rainy and cloudy from the morning.

There still remained cloud near the mountainous area, but it seemed that the amount of cloud in the region also disappeared rapidly. I decided to go comet hunting at one of the best sites with an altitude of 800 m where it took one hour by car.

Lovely sunset! At the site, the sky was crystal clear. I finished setting up my comet-seeker at 7:20 p.m. The Milky Way arched over the sky with dark-lanes that reminded me that I am a member of our galaxy.

I wondered from where I started comet searching. The ecliptic was in the southwest where the light pollution of Nagano city messed up the sky. The south was full of summer showcases, but I dared to seek minor area: Bootes where there are no major DSOs and only dark galaxies can be observable.

Even at such a good observing site, at dusk all the sky less than 40 degrees in altitude looked very bright due to light pollution. The contrast in the field of view was not satisfactory, and I wondered no galaxy would be identified. It might be a monotonous session.

NGC5600 (left) and NGC5962 (right). The width of the image is 5f.
The Digitized Sky Survey copyright (c) 1994

However, I noticed a very faint object at the low altitude, some 20 degrees. I could not have recognized it, if it had not come into just the center of the field. The NGC Max identified the object as NGC5600, 12th magnitude galaxy. It was surprising that such a dark galaxy was spotted at the low altitude under the light polluted sky. The contrast looked low, but the limiting magnitude got darker with the help of the high altitude.

Another galaxy I met was NGC5962, 11th magnitude, in Serpens. It passed near the edge of the field, but it was easily recognized.

Both of the galaxies looked like small patches, but now, I knew that they have unique appearance to see DSS image.

Wednesday August 26

An alarm clock woke me up at 1:50 am. The sky was clear!

Before the comet hunting session, I trained the comet-seeker at C/2006 W3 Christensen that was in the constellation of Sagitta, low in the western sky. Nevertheless, it looked bright with a short tail.

I wanted to begin with the adjoining region that I swept yesterday, i.e. western part of Orion. However, only the ESE of the sky was cloudy, and I started from near M1. I did not know Mars was in Taurus. The apparent diameter was easily recognizable with 67x, and I was sure that it was not a nova but Mars. M35 and NGC2158 were lovely, and the latter resolved into stars with 67x. I felt as if I had met an old friend, because the area has been hidden by the sunlight for some months and one could see the clusters.

M35 and NGC2158 (right bottom)
The photo is 50 arc minutes wide.
The Digitized Sky Survey copyright (c) 1994

I identified a planetary nebula NGC2392 (Eskimo nebula) in the twilight, which usually I miss, since the nebula is so bright that it is difficult to distinguish it from a star. This time, the twilight diminished the contrast of the nebula, and I could spot it. Instead, I overlooked a dark planetary nebula NGC2371 that I have often identified.

Changing the eyepiece to Ethos 13 mm powered by a barlow lens, 313x, Eskimo was smiling in the scintillation. How lucky and satisfactory to comet hunt two consecutive predawn after long-lasting nasty weather!

Tuesday August 25

Autumn has come. It seems to be too early, but the atmosphere is getting cool with good transparency. Above all, the weather began to recover.

I got up at 2 am, but as the forecast said it was cloudy and I went to bed again. However, I anticipated the recovery of weather as I had noticed some small gasp in the cloud. At 2:20 am I got up again and it was getting better, and I decided to comet hunt.

When I completed setting up my comet-seeker at 2:55 am, the amount of cloud reduced to 50%. I aimed the telescope at the constellation of Eridanus where it was cloud less. I expected that I would encounter some dark galaxies in the region, and in 10 minutes I spotted the first one. It was an elongated object with 11th magnitude. Unexpectedly, the NGC Max could not identify the object, and at the next moment I remembered 217P LENEAR is in Eridanus. I compared the position with the comet list on the pad, and it actually turned out to be 217P.

In the end, the deep sky objects that came into the field during the session were only M79 and NGC1600 (galaxy). At 3:50 am cloud began to cover the sky rapidly, and the sky was overcast at 4 am.

Fortunately, I could enjoy one hour hunting session.

Mon Aug 10

Unexpectedly, I could observe the impact spot on Jupiter tonight!

I have not set up my comet-seeker for about one and half month due to terrible weather. TV news said many people died and were missing in western Japan today because of food brought by Typhoon Etau or Typhoon No.9. I wonder if rain and cloudy weather continues till autumn, as El Nino that is the cause of bad wather is getting stronger.

At 10 p.m. when I was about to go to bed, I noticed moonlight was casted into the room floor from the window. Jupiter was shining! I have confirmed if the impact spot on Jupiter was visible using Internet, and it turned out that the transit time was around 11p.m.!

I hesitated to set up my 46 cm telescope and wondered smaller one would be better; while I was setting up the 46 cm Jupiter might be hidden by cloud. Fortunately, the gap of cloud was getting larger with time, and I decided to use the 46 cm.

It took 15 minutes to complete assembling and collimating my comet-seeker. Using Ethos 13 mm at 157x the impact spot was easy to recognize at a first glance! It was highly elongated and streak-like. While seeing was deteriorated the spot disappeared in the turbulence at any magnifications. Even so, with a little patience seeing recovered it appeared again.

If the impact occurs on Earth, we human beings including other creatures face the extinction. Imagine an asteroid or a comet is approaching to Earth and the impact may sweep all of us: all we need is to save ourselves by all means. Donft you feel how stupid it is to engage in warfare? It was what the impact told me.

Thu Jul 30

Rainy and cloudy! No one could observe the totality in Jiaxing, China on July 22.

Till the day before the totality, I heard it had been fine, and it was consistent with my cloud observation over the area using the image of the meteorological satellite.

Just after most people had completed setting the telescopes, it began to rain. It ceased before the totality, and we could enjoy darkness. Several minutes following the third contact, we could observe Venus and partial eclipse through the gap of cloud.

If the gap had opened earlier, we could have observed the totality for a while!

We were disappointed the situation but enjoyed tourism in China.

I would like to try the total eclipse again; however, the totality tour to the Easter Island in 2010 is too far and too expensive. I wonder if I could go over Australia in 2012.

Haneda Airport in Tokyo
Before the totality it was raining.@

Some ten minutes following the third contact.

Yu Yuan (Garden in Shanghai)
Shanghai Acrobatics

There were five motor-bikes in the cage!

Sun Jul 12

I have not conducted comet hunting since Sunday June 21 because of my fatherfs death on June 25. He was 81 and had been in a nursing home for one year due to dementia. My mother and one of my sisters were at his death bed, but he had gone five and half hours before my arrival. It was natural death, and we believe his was satisfied with his life. It seemed for me that the superb sky on Sunday June 21 was the last smile from my father; he used to appreciate my passion for the night sky in my boyhood.

It has been rainy and cloudy for more than a week now that it is rainy season, while the total eclipse is just around the corner. Rainy season has finished in Japanese southern islands of the totality zone, and I think it will be finished soon in Shanghai area, China where I visit the next week.

Clear sky and great totality!

Sun Jun 21

Summer solstice!

It has been cloudy, rainy, and foggy for nearly three weeks during the nights, even if it was fine in daytime or forecasted fine. Contrary to the weather report, the sky was crystal clear at noon.

As I will attend the eclipse tour in China next month, I checked the solar filter and the optics aiming them at the sun. Now, they are ready for the departure! The totality will be the first experience for me. I do not want to take many photos, but to enjoy visual observation.

Instrument for the totality tour in China. BORG125ED and Docter Optic Nobilem 8x50B binocular.

Note that the solar filter is installed in Quik Finder on BORG; it does not work under the sunlight due to lack of LED brightness, though it was OK in the room.

The clear sky lasted till dusk, and I decided to go comet hunting to one of the best sites, in spite of the pessimistic weather forecast that predicted it would be cloudy at night. I arrived at the site during the twilight at 8:20p.m. and looked up the sky; Arcturus looked much brighter than usual that meant excellent transparency! Just when I completed setting up the comet-seeker, I was clouded out as predicted!

I waited for some 10 minutes, and luckily there appeared some gaps in the cloud in the west. It was not wide enough to be able to comet hunt, and I trained the telescope at Saturn. Superb! Seeing was excellent, and I changed the magnification as high as 500x using Ethos 8 mm and barlow. Even at 500x the image was rather clear and the shadow of the ring casted on the body of Saturn was outstanding.

The cloud gaps near Saturn closed, but the amount of cloud reduced with time. C/2008 Q3 Garradd was in the cloud but I aimed at the comet using the NGC Max, and I could observe it! It had large apparent diameter, but disappeared in a minute. I noticed that Scorpius was vim and vigor as if it had included many first magnitude stars. It reminded me of the sky at Mauna Kea, Hawaii!

I finally began to comet hunt at 9:15p.m. but was forced to sweep here and there, since cloud moved into and hide the sweeping area many times.



The image is15f wide.

The Digitized Sky Survey copyright (c) 1994

One of the galaxies I spotted during the session, NGC5248 with 10th magnitude, had apparent spiral structure at first glance at 68x! I finished the comet hunting session at 10:20 because I wanted to enjoy watching DSOs. M8 and M20 looked pink and blue colored, and I recognized central star of M57 at 500x: it was twinkling and was seen intermittently with averted vision for one quarter of observing time. M22 and M5 were striking! M17 did not look like a shape of swan but did strange: Omega?! I made a quick sketch.


M17: 46 cm, Ethos 13 mm, 157x

Stars are not drawn.

The limiting magnitude with naked eyes seemed to be 6.5 at most, but the combination of excellent transparency and seeing made the sky superb. I wanted to continue stargazing through the night, however, had to report to work the next morning. I took down the comet-seeker before midnight and got home at 1a.m. I was very excited with the wonderful sky, but exhausted and had a good sleep.

Tue June 2

I got up at 0:40a.m. and started the comet hunting session at 1:30a.m. in front of my house. I lost some 10 minutes before starting the session because of incredible mistake.


To set up the digital setting circles, firstly, I trained my comet-seeker on Alpheratz, Alpha Andromedae, which had just appeared above a forest stand. Secondly, I aimed it at Polar Star, but the NGC Max showed an error message. I tried to again; however, the result was the same. I checked if the setting of the encoder was right and the cables were connected correctly. They were all OK.

I did not know what happened. Anyway, this time, I used a different pair of stars for activating the NGC Max, and finally it worked correctly.

After half an hour, I noticed that the star I believed to be Alpheratz was Algenib, Gamma Andromedae (corrected on June 7, 2009) Pegasi! How careless! Alpheratz is lower right of Pegasusfs quadrangle when Pegasus is in the west, while Algenib is lower right when Pegasus rises from the east. This is one of reasons. In addition, you cannot recognize the asterism of the constellations, when the constellations are low on the horizon and some of the stars are hidden. These are the cause that I made a mistake.

Alpheratz, Alpha Andromedae and Algenib, Gamma Pegasi.
This figure is added on June 7, 2009.

During the one hour and forty five minutes session, I identified only one DSO, M2. There are few DSO around the region, i.e. the east of Jupiter to Pegasus.

To change the subject, it was pretty cold this predawn. Air temperature was only 9 degrees Celsius with breeze. I wore light down jacket and pants upon starting the session, but 20 minutes later I changed them to heavy ones (cf. Comet hunting wear). On the contrary, in daytime, air temperature rose as high as 30 degrees! You have to pay much attention to large temperature gap and lack of sleep in this season.

Sat May 30

Regardless of optimistic forecast, it had been cloudy during the nights this week. This predawn I got up at 0:40a.m., as I did a couple of times this week, and finally, I had a chance to conduct a comet hunting session.

Transparency was pretty good without cloud. I hoped that this situation continued until the daybreak, but when I completed setting up my comet seeker, cloud began to spread! The only cloudless area was Sagittarius, and I was forced to search the area.

The first object I encountered was M24. There are quite a few of star clusters and nebulae in this region, and I had a good time with observing them. M22 was always striking, but the most impressive object I identified during this session was a globular cluster, Palomar 8 (about 2.5 degrees east of M25: RA: 18h 41m 30s, Dec: -1949' 33"). Maybe, I caught it for the first time. It was very faint with dark surface brightness, 11th magnitude and some 2f in diameter. When I observed this cluster at 2a.m., thin cloud began to cover the area, and I was forced to turn my scope from the south to the southeast.


Palomar 8

The image is15f wide.

The Digitized Sky Survey copyright (c) 1994

In the new sweeping area there was 22P Kopff, but I could not spot the comet probably due to thin cloud that began to cover the area, and the defused image of the comet; it was reported that the comet had a magnitude of around 10 with DC (degree of concentration) 2. At 2:35a.m. the cloud spread my sweeping area, and I must change the search area again. I trained my comet seeker on the constellation of Pegasus.

In the twilight I took a break to observe C/2006 W3 Christensen. It was lovely and bright with a graceful wide tail!

I finished the session at 3:05a.m., when Venus rose above the SE horizon.

Wed May 13

I have had a clod since Saturday (or maybe the flu but I do not know how to distinguish them), and took sick leave on Monday and Tuesday. I consulted a general practitioner, but could not get rid of it with ease. I reported to work today, though I still have slight nasal inflammation with sore throat.

When I finished todayfs work, the sky was getting cloudless with superb transparency. I decided to go comet hunting. I spent one hour drive from my home to the observing site where the altitude is some 800 m above sea level. Before I started the comet hunting session, I tried to observe two comets: C/2009 F6 Yi-SWAN and C/2008 T2 Cardinal.

I did not prepare the finding charts to introduce these comets, and depended only on the digital setting circles inputting the R.A. and R.D. with a magnification of 68x. At 8:20 p.m., 10 minutes before the end of the twilight, C/2008 T2 was identified easily. I felt it was discoverable during a comet hunting session, and estimated the magnitude was 11th with a diameter of 3f by intuition. While I could not observe C/2009 F6, probably because light pollution and the low magnitude of the comet.

I swept in the constellation of Gemini mainly, and spent one hour and thirty five minutes. I caught a planetary nebula, NGC2371. The irregular shape of the nebula was obvious at first glance. As usual, I overlooked Eskimo nebula, NGC2392, since it is so bright with small apparent diameter of 50h that you cannot tell the nebula from a star.


The image is10f wide.
The Digitized Sky Survey copyright (c) 1994


The image is processed so that it is similar to the visual image of 46 cm 157x. The image is15f wide.
The Digitized Sky Survey copyright (c) 1994

The session itself was comfortable, but light pollution was serious than at predawn especially near the horizon. I completed sweeping before 10 a.m. and then, enjoyed DSO using Ethos 13 mm with a magnification of 157 till the moonrise. The spiral structure in M51 and M101, which was apparent with a direct vision, was impressive that looked like photos. Five or more spiral arms were recognized in M101with bright HII regions. A swarm of stars in globular clusters, M13, M3 and M5, gave an impression of 3D.

I finished taking dawn my comet-seeker at 11p.m. and got home before midnight. I had a good sleep with attaining the peace of mind of satisfaction.

Thu Apr 30

It has been clear for three consecutive days! I swept the predawn sky today and the day before yesterday: yesterday, I went mountain-climbing with my friends from early in the morning, and I gave up comet hunting with painful reluctance. I often go one-day hike and skiing for fitness that is a basis of all of my activities including comet searching. Taking a balance among many activities within limited time is a critical issue at any time.

As the summer solstice approaches, you have to get up earlier for the predawn comet hunting session. I went out of the bed at 0:55a.m., and drove to one of the usual observing sites. The sky was cloudless. Transparency was moderate at the high altitude but bad at the lower part of the sky.

I began to sweep from the east wing of Cygnus; the north-eastern sky seemed to be less light-polluted in comparison with the other direction. Soon after the beginning, I encountered a huge nebula, Veil Nebula. Only two comet-like objects, galaxies NGC7217 and 7331, came across the field. The highlight of the session was to have identified C/2006 W3 Christensen. Impressive! The comet was bright with 9th magnitude by intuition, and had a short wide tail. I cannot remember the time when I caught a known comet last during the comet hunting session.

When I completed the session, Jupiter was in the south-west, and Venus, as dazzling as Jupiter, rose above the horizon.

Sat April 11

C/2009 G1 STEREO was discovered from the image of the STEREO satellite. My search area on Monday, April 6, covered the position of the discovery.

As I described in my diary that updated on Wednesday, I identified M15 during the comet hunting session at Monday predawn. The comet was located at almost the same azimuth with M15; strictly speaking, the difference in the azimuth between the two objects was 0.2 degrees at 4:15 a.m., the time when I supposed M15 came into the field of view. I remembered that M15 passed through the field of my comet-seeker twice, as I overlapped it enough.  This means the comet also must cross the field, since I swept the sky vertically as usual.

I could not spot the comet as a result, because it was 20 minutes after the beginning of the twilight when I reached the comet with the magnitude of 10-11 and the altitude of 13 degrees above the horizon. Even worse, transparency was moderate.

In my diary I wrote that elong-term devotion and good luckf are necessary for discovery. This time I could not due to the absence of good luck.


Mon Apr 6 – Tue Apr 7

I could comet hunt for two consecutive predawns. At Monday predawn, transparency was moderate, but scintillation was steady and I could concentrate on weeping the sky. The deep sky objects I identified were NGC6934, a globular cluster in Delphinus, M2, NGC7006 also a globular cluster in Delphinus, and M15. As the sky condition had been poor for one month, this comet hunting session was satisfactory.

When I finished comet hunting session, the great triangle in summer rose high in the sky and Jupiter was above the horizon.

At Tuesday predawn, the time difference between the moonset and the start of the twilight was only 10 minutes. The waxing moon was bright, nevertheless, I began to search the heaven 20 minutes before the moonset. The sky was much dustier than that of yesterday, which made light pollution serious. I employed the light pollution filter, IDAS-LPS-P2, to enhance contrast. Usually, I do not use the filter since it causes color aberration and spoils the beauty of star field.

The limiting magnitude for comet-like objects seemed to be 10th or brighter under such poor sky. I felt fulfilled for the session with fine star ground in the summer Milky Way.

A new comet, C/2009 F6 Yi-SWAN, was discovered by Dr. Dae-am Yi and SWAN. The position was out of my search area. I have yet observed this comet, but Seki reported the magnitude was 11.5 using 15 cm refractor. I believe both C/2009 E1 Itagaki and this comet could be discoverable using 46 cm comet seeker under good sky condition.

Long-term devotion with good luck leads you to discovery.

Tue Mar 24

I got up at 1 a.m., 2 a.m., and 3 a.m. this predawn. I did not know if the weather forecast was off the mark or not (see the figure below), but cloud had covered the predawn sky. Unfortunately, this happed many times this month.

Weather forecast released at Monday dusk.

At dusk, you can observe a new comet discovered by the Japanese comet hunter Koichi Itagaki, C/2002 E1 Itagaki. I had a look at it on Tuesday March 17, but at that time the sky was very dusty because of dense yellow sand from Chinese desert. I could manage to identify the comet using my 46-cm comet seeker.

I knew Itagaki by name since my boyhood, since he is an independent discoverer of C/1968 H1 Tago-Honda-Yamamoto. Though his discovery was the first one in the world, he informed it using express mail, and his name was not given to the comet. Recently, he discovered dozens of supernovae, but in an astronomical magazine he said he actually wanted to find a new comet. Last year, he spotted D/1896 R2 Giacobini with Hiroshi Kaneda.

I congratulate him on the discovery!
I was inspired by his grand achievement, and am eager to comet hunting under the clear sky.

Greatness is the dream of youth realized in old age.
-Alfred Victor Vigny

Fri Mar 6

Like yesterday I expected the clear sky, as the forecast predicted the sky would be clear at predawn. I got up before 3 a.m., but this predawn I was clouded out.

Thu Mar 5

The alarm-clock woke me up at 3 a.m. It was rather warm that implied cloudy, but unexpectedly, the sky was clear with excellent transparency. I was happy to go out to set up the comet-seeker.

I was bewildered at the outside! The quarter was encompassed with dense fog. I did not feel cold in the bed because it must be foggy or cloudy just before I got up, and accidentally, it was fogless when I had a look at the sky from the window.

I had no choice. Instead of comet hunting near my house I drove 20 minutes to one of the usual observing sites, however, it was cloudy there. I did not give up the hunting session and decided to set up the telescope, as there were some small gaps among the cloud. Just when I completed setting up the comet-seeker, starry sky started enlarging in the north north-east.

As I saw at my house transparency was pretty good, but filmy clouds crossed the sweeping area from time to time. I expected to identify a few galaxies in this region, Draco and Cepheus. Unexpectedlly, NGC6951 was the only galaxy I caught; the galaxies would be hidden by the cloud. Nonetheless, delicate autumn Milky Way in the region was impressive and I had premium time.


NGC7133. Reflection nebula in Cepheus.

The image is 15f wide.
The Digitized Sky Survey copyright (c) 1994

At the t beginning of the twilight a sparkling and exquisite open cluster came into the field. I did not know what the cluster was. The NGC-Max told me it was NGC7789 in Cassiopeia. The next object that made me excited was reflection nebula. It looked like so at a glance since the object was superposed on some bright stars. I checked it out using the digital setting circles that said the object was NGC7133, a reflection nebula, as I thought.

I completed the session at 5:15 a.m. more than 30 minutes following the start of the twilight. The sky turned into cloudless before I knew it.

Tue 24 Feb

Last dusk there were two kinds of forecasts for the coming predawn, one said it would be clear and another stated cloudy. I worried one more thing, fog. Anyway, I went to bed early at 9p.m.

I wake up at 3a.m. It was rather warm that often implied cloudy weather. I approached the window, and it turned out that the outside was encompassed with a dense fog. I gave comet hunting up, and went back to the bed.

Sun 22 Feb

I got up at 2:30a.m. Since the sky was crystal clear, C/2007 N3 Lulin was easily recognized with naked eyes from the window! When I began to set up my comet seeker, the comet could be seen with direct vision with an apparent diameter of about 10f. In five minutes, suddenly, thin cloud spread all over the sky. I waited for around one quarter, and the gap of the cloud enlarged. I started comet hunting, however, transparency apparently reduced in comparison with twenty minutes before.

I began with the constellation of Scorpius as the gap opened only in the region. An impressive double star, Beta Scorpii, which was dancing coincide with scintillation, and many globular clusters, M80, M4, etc, came across the field of view. Even through the thin cloud I enjoyed many summer showpieces.

This predawn I looked forward to observing C/2007 N3, nonetheless, the comet remained being hidden by the cloud. I patiently waited for its appearance out of the cloud while I was sweeping the sky. Finally, the comet got out from the cloud, and again I could see the comet with unaided eyes, but looked dimmer and smaller because of thin cloud. With my comet seeker the dust tail of the comet stretched as long as over one degree. The ion tail was difficult to observe, and I could identify only a hint of it.

I resumed the hunting session, but transparency got worse with time. I finished the session 10 minutes following the beginning of the twilight when the thin moon with Earth light rose.

Thu 5 Feb

As I worried, it was a little bit foggy around my house this predawn, and I spent 20 minutes to drive to one of the observing sites. The transparency was good but not excellent with thin cloud at the low altitude. It was not so cold, but from time to time a breeze robbed me of my body heat. Every time when it blew I wore a hood of my polar jacket, since a woolen cap was not warm enough.

Before starting the session, I tried to observe 210P Christensen. The comet was introduced in the center of the field by the digital setting circles, however, I could not recognize it. Using a finding chart that I printed at home, I could manage to confirm the comet that had about 10h in apparent diameter with 12th magnitude. It was too small to identify during the comet hunting session. On the contrary, C/2007 N3 was bright with long tail. The iron tail looked 1 degree or more but it was not sure how long it was since very thin cloud covered the region.

I began with the hunting from the left hand of Hercules: he held snakes and apple branches with it. As the same with last Thursday I detected M27, M57, M56 and Albireo, all of them looked more beautiful than a week ago because it was in the twilight a week ago. In the constellation of Lyra I came across a very faint object that I would have overlooked if the object had not entered at the center of the field. It seemed to be a galaxy judging from the appearance. The NGC Max said it was NGC6675 with 12th magnitude. Probably, this is the first time I observe this object. After a while, another faint object astonished me. It had some 10f in diameter with low surface brightness, and seemed to be an open cluster. Again, the NGC Max identified it as a known object in a several seconds: NGC6791, an open cluster in Lyra. After I got home I wanted to know if the object is listed in the Seki or the Tago Catalog: it is not listed in the Seki Catalog but in Tagofs that reads ea magnitude of 11.5 with a diameter of 7f and diffusedf.

NGC6791. The image is 15' wide.
The Digitized Sky Survey copyright (c) 1994

I could observe those faint objects, but cloud spread higher altitude with time. The entire eastern sky was covered with cloud when the twilight began.

Thu 29 Jan

Yesterday I got up at 3a.m. and 3:30a.m., as the forecast predicted fine weather. Actually, cloud covered the entire sky. The weather changed at the time of the sunrise, and since then it had been clear. I observed P144 Kushida for the first time last dusk using the 30 cm Hawaii telescope. The telescope was handy and can be set up in five minutes! The comet was placed near Gamma Tauri, and had some 10f in diameter with 9th magnitude.

This predawn the air was much milder than on Sunday and Monday, -3 degrees Celsius. I was exhausted due to low temperature on those days, but thanks to this gcomfortableh climate not only me but also the primary mirror adapted ambient temperature rapidly today. Even so, the star image was not perfect pinpoint at the beginning of the session. When I came across the first comet like object, NGC6181 in Hercules, the elongated image was large enough to recognize as galaxy, and the NGC-Max identified it. Some five minutes later, I met another non-stellar object.

I felt it must be a double star at a glance, and I peered into it for a while. It never split into two or more stars, and the NGC-Max could not tell what it was. I told myself that I should not omit to confirm the true form of the object, and finally, I decided to change the eyepiece from Planocular 30 mm to Ethos 13 mm: it took some effort as a dew remover was wound around the eyepiece. As soon as I changed the eyepiece, the object was split into two easily.

After that, as the telescope approached to the Milky Way, many double or multiple stars that seemingly looked like non-stellar objects came into the field. Those resolved into stars in a second since the optics was already well acclimatized.

Great many stars shone in the field of my comet seeker, but I was somewhat unsatisfactory not to encounter comet like DSOs any more around the region. As twilight progressed I happened to meet several summer showpieces: M71, M27, M56, M57, and Albireo. I felt as if I had met good old friends, and completed the session with satisfactory.

Sun Jan 25

It snows heavily this week in most part of Japan Sea side, especially Western Japan, while my city we have less snow than usual winter. Typically, snow depth reaches some 150 cm at the end of January, but this year it is only 60 cm today. As with last month, the weather tends to be fine.

The sky has been clear with some drifting cloud since last dusk. I started sweeping the sky at 4:00 a.m. Temperature was -8 degrees Celsius, and it was hard work to comet hunt. This time I was sure to begin with Alpha Librae, and expected to catch C/2007 N3 Lulin and P/2008 X4 Christensen. During the first half an hour I was irritated by the blurred star image. I thought it was caused by bad seeing, but I saw that the primary mirror did not adapt to the ambient air temperature after a while.

As the star image got clear, in turn cloud started to spread that occupied more than half of the sky. I continued to comet hunting, even if the thick cloud completely hided some part of the searching area or through thin cloud. C/2007 N3 that went across the field of view during the hunting session was very bright and had the two tails: the ion and the dust tail. The angle of those tails was 180 degrees! The length of the ion tail looked over 0.5 degrees but the dust one was short: the former might be longer, since I observed it through cloud.
The amount of cloud augmented as time went, and I could not catch Comet Christensen partly due to thin cloud.

NCG6070. The image is 15f wide.
The Digitized Sky Survey copyright (c) 1994

The number of the DSO that I identified was 15. They were globular clusters except two: NCG6070 that is a dark elongated galaxy in Serpens and M8. Just after I caught NCG6070, it disappeared in the cloud and several second later it could be recognized again. What happed if this object was a new comet? I might overlook an actual one that was veiled in cloud.

Weekly forecast.  (c) Yahoo!

The trend in fine weather will last through this week that is rare in January.

Thu Jan 8

I suffered from stomachache and headache due to overwork last month, and took sick leave on Tuesday and Wednesday. Though my health condition was not perfect this predawn, I wake up and comet hunted as a precious clear sky was waiting for my searching session.

I drove to the winter observing site, and started from Alpha Librae expecting C/2007 N3 Lulin and C/2008 X4 Christensen being caught during the session. After a while I noticed something was wrong, since unexpectedly some galaxies came across the field of view.

It turned out that the star where I started with the comet hunting session was not Alpha Librae actually, but Iota Centauri! I took a pair of Theta and Iota Centauri for that of Alpha and Beta Librae. OK, it was no problem. Few comet hunters search such far south area! On top of that, this might be the region where I have never swept.

NGC5068. The image is 15f wide.
The Digitized Sky Survey copyright (c) 1994

As transparency was almost prefect with temperature of -5 degrees in Celsius, I could identify as dark as 13th magnitude galaxies. NGC5068, a face on galaxy, showed a hint of spiral structure when it came into the field.

At 5:40a.m. a quarter after the beginning of the twilight, I observed C/2007 N3. The comet was very bright with a short tail. On the other hand, I could not observe C/2008 X4, probably because of the light pollution of the ski field.

I completed the hunting session at 5:57a.m., and identified a total of 20 galaxies.

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