Wed Oct 4
I have discovered a new comet this predawn!
However, the comet turned out to be C/2006
T1 Levy, which was announced IAUC only 3 hours and 43 minutes before my
discovery.
How sever it is!
The ‘discovery’ story is here.
After one hour drive I arrived at one of the best observing sites at 7:15pm. The collimation of my 46cm comet seeker had completed at 19:27pm and I started comet hunting session at 19:38pm. Only after 10 minutes cloud covered all the sky.
Luckily, cloud gap spread in a few minutes and I could continue comet hunting, though cloud still covered most part of the sky. Around 9pm, the sky became clear without cloud. However, I got tired and stopped comet hunting at 9:25pm.
Then, I observed 4P/Faye and 177P/Barnerd with Lumicon Comet filter. Contrast was much enhanced for 177P and it looked much brighter using the filter. On the contrary, 4P was slightly darker with the filter, that is, the filter gave an opposite effect for this comet. I have applied other two filters, IDAS LPS-P2 and IDAS LPS-V3 filters, for some comets. All the filters showed positive effect or at least no effect for all the comets, but this is the first time that the filters revealed the negative effect.
Under
the Milky Way: The supreme time 2006
Sep 20
After some 4 hours sleep in my vehicle, I
got up at 2am. Wonderful sky! I could observe M33 by my naked eyes with
direct
vision. I could even observe its shape. M31 was about to immerse into
the Milky
Way! I wondered if the Milky Way was so wide.
After enjoying some deep sky objects I
began to comet seeking at 2:35am but unexpectedly, it was cloudy again
in 20
minutes. After that I cloud comet hunt only additional 20 minutes. Even
so, I
did do my best; I searched southeast, where Kreutz Sungrazers would
appear.
Sat Sep 2
Sun Aug 27
I did not intend to get up this predawn, but fortunately I did before 3a.m. due to a bike noise of a newspaper carrier. About 40% of the sky was covered with cloud; however, the sky condition was good enough to do comet hunting.
It has been cloudy through the night in spite of clear sky during daytime in the latter half of this month. In Friday predawn I went out and assembled 46 cm telescope under the excellent sky condition; clouds spread all the sky when I finished assembling the telescope until the beginning of the twilight. It was momentary fine weather. Yesterday, I woke up at 4a.m., and it was cloudy as the weather forecast predicted. Today, it was exceptional.
OK, went out and began!
However, it was less than one hour until
the beginning of the twilight and it was time consuming to assemble 46
cm comet
seeker; it takes some 30 minute to stand by. This time, I decided to
use 20 cm
telescope. To initialize the digital setting circles I trained the
scope on
Capella, Alpha Aur, and felt if it was actually Capella because it
looked much
darker in the field than usual. Soon I recognized that I used 20 cm
instead of
46 cm and understood the reason.
NGC1907, open cluster near M38, looked like
a comet with this instrument, but it is resolved using 46 cm that I
routinely
employ. 20 cm is comfortable to operate and is easy to assemble, but
the light
gathering power and the resolution are much less than those of 46 cm. I
prefer
to use the larger one if I can afford, since I can detect darker comet
that
many hunters miss.
Tue Aug 8
The saying of ‘10 days after the end of the rainy season’ just fits this summer. It means that clear sky continues for 10 days from the termination of the rainy season that was July 30 this year. I conducted comet hunting 6 times this month so far.
This predawn the transparency was pretty good, though the time between moonset and the beginning of the twilight was only 30 minutes. I began to sweep the southeastern sky at 2:30 am, when the moon was still at the western sky.
The field of the telescope was rather bright with low contrast due to the moon light, and it made difficult to split faint double or a multiple star that looked like a comet. I sometimes stopped the motion of the comet seeker and peered into the comet-like object or must change eyepiece to confirm if it was actually the double or the multiple star with higher magnification. For this purpose I use Naglar 12 mm with 170x.
The field became darker and the contrast was getting higher as the moon declined. It was easy to split faint multiple stars after the moonset because of dark background.
I caught several galaxies in Cetus and Eridanus. I wonder how far these galaxies were, and if dinosaurs were alive when the light I saw left the galaxies. One of the galaxies I observed was M77 that is 65 million light years far (The Night Sky Observer’s Guide, Willmann-Bell Inc.); this light left for us just when dinosaurs became extinct.
Stars in our galaxies, quite a few of which went through in the field, are much closer; they are hundreds of or thousands of light years. I felt 3D effect by imagining the distance of those objects.
Again, the S/N (signal and noise) ratio became low. This time it occurred not by the moonlight but by the twilight. It is full moon tomorrow, but I could enjoy comet hunting this predawn since the moon was at low right declination and it set early.
Fri Jul 14
There was a storm at the night of June 30,
and the total rainfall amount in June did not record its minimum for
the 90
years as I described on June 29.
This evening the sky was fine with a small
amount of cloud. Before leaving my office I tried to check the time of
the end
of the twilight and the moon rise. I thought that there must be enough
dark sky
period to do comet hunting this dusk, since I knew it was the full moon
a few
days ago. OK, the Astronomical Pocketbook read there was more than one
hour!
After
I got home and finished supper I left home for the upland to comet
hunt. On my
way to the observing site the coverage of the cloud began to rise and I
noticed
the top of some mountains were in the clouds.
Anyway, I arrived at the site and assembled
my 18 inch telescope. What a wonderful activity to assembling the
telescope
hoping for the starry night that I could enjoy in half an hour! I
especially
felt so, because I had not swept the sky since June 13 due to nasty
weather.
When I completed the assembling, cloud spread all over the sky; all the stars I could see in the sky through the cloud were Arcturus and Jupiter. In a little while those two stars disappeared. I spread the plastic sheet on the ground and lay down on it to wait for the emergence of the cloud gap. Warmness of the ground was comfortable but no stars appeared in the sky. I disassembled the telescope and left the site around 9 pm after all.
Usually, the weather condition in the rainy
season is worse than in winter when we have a few meters of snow here
on the
Japan Sea side; I could comet hunt at least once per month in midwinter.
Wed June 29
The rainfall amount this month is the smallest since the beginning of the observation in 1917 in my workplace, Tohkamachi Experimental Station, if no rainfall would be observed tomorrow. Even so, there were few nights that the comet hunting was possible: I could do it only twice this month. The sky is covered with thin cloud tonight also, though the forecast predicted clear sky.It was exciting that LINEAR spotted P/1889 M1 (Barnard 2) after 117 years' separation one week ago. How wonderful it is the comet was discovered unexpectedly after over one century of the first discovery. If the discovery had been made by an armature, especially visually, the story would have been much cooler!
Greater dream for most comet hunters are to discover a periodic comet or a great comet. There still must be such chances for every hunter.
I
am inpatient for the clear sky.
Sun
Jun 11
I
could sit back and relax in the bed at
predawn on this week end, because it is full moon today.
This
month it has been depressing weather
and I could comet hunt only once so far, on last Sunday June 4, in
spite of
optimistic forecast as the end of last month.
I
wonder if the amount of cloud is boosted
by the Global Warming, and it gives rise to the number of cloudy days.
I think no
meteorologists can prove whether this scenario is correct or not due to
lack of
data and incompleteness of the modeling. Anyway, reduction in the
number of clear
days is disappointing.
Another
bad news for me is that the new
solar observation satellite will be launched next month: STEREO (Solar
TErrestrial RElations Observatory)
http://stereo.gsfc.nasa.gov/mission/mission.shtml
According
to Karl Battams, via Hirohisa
Sato OAA-comet mailing list, coronagraphs are equipped in the satellite
and images
will usually be taken as +90/0/-90 -degree triplets. The instruments
would be a
new threat of comet hunters, especially low altitude hunting near the
sun.
You
do not know what will happen until the operation
begins. However, it is yourself who judge if the new satellite really
threats you
or not.
Winners
never quit, and quitters never win.
-Ted
Turner (U.S. broadcaster
and sports executive, 1938- )
Sat May 27
The forecast said clear sky prevails at this predawn and I got up at 1
am and again at 2 am. It was cloudy, however. Ironically, the sky is
very clear this morning; probably since the sunrise.
Yesterday’s predawn, the circumstances was similar: I went out of the
bed at 1 am but no stars were twinkling on the sky, although the
prediction claimed it would be fine.
At the predawn of Thursday also, the situation resembled that of today
but it was better: the forecast predicted clear sky and I got up at 1
am but in
vain. I looked at the sky again at 2:18 am and it was clear! The
twilight began at 2:43 am and there was no time to assemble my 18 inch
telescope and to move to the usual observing site where the sky
condition is superior. Instead,
I assembled my 8 inch reflector in front of my residence. I could
search
the lower part of the eastern sky with 31x for 40 minutes.
The forecast in this season is difficult since a slight motion of the
Rainy Season Front changes the weather drastically, though the mesh-weather forecast
system in
our country is one of the best in the world, I believe.
The Japan Meteorological Agency (JMA) made a public announcement
yesterday that the southern part of the Kyusyu Island, the southwestern
Japanese Island where comet hunters Utsunomiya and Kudo live, entered
the Rainy Season. Hyakutake also lived this Island. I guess that the
area I live would do in a couple of weeks but Japanese Rainy Season
does not necessarily bring constant rainfall; usually it includes some
clear days. I have to watch out for the weather not
to lose the chance.
Wed May 10
Moon set at 2:54am and the twilight began at 3:01am. I did not have
enough time to do three kinds of activity: taking photos, visual
observation, and comet hunting.
At 2:30am I had assembled both 18 inch telescope for comet hunting and
an equatorial mount for taking some photos of 73P Schwassmann-Wachmann
fragments. Fragment C approached Beta Cygni, Albireo and fragment B
passed near Alpha Lyrae, Vega. As a result, I failed to fragment C due
to out of focus.
I am trying astrophotography not only just for fun but for practice:
when I spot a new comet, I want to confirm it by photos.
Fragment B that busted was easily visible by naked eye and looked over
one magnitude brighter than M13: It must be magnitude of 4th to 5th and
also looks brighter than
Epsilon
or Zeta Lyrae in the photo. However, visual observation I made last
evening by 5 cm binocular resulted in magnitude of 6.1 and rough
estimation
at this predawn was almost the same.
Many observers estimated it as 6th magnitude using binoculars. This
sort of discrepancy, including the differences in magnitude estimation
between visual observation and CCD, has been pointed out by many comet
observers
but the exact cause is unknown.
I could spend 35 minutes for comet hunting from 3:10am.
Thu May 4
I have arrived at the observing site at mid night, because I tried to
astrophotography with guiding for the first time since my boyhood; I
took the last one more than 25 years ago. Off course, tonight I aimed
at 73P
Schwassmann-Wachmann Component C and B.
The results were not satisfactorily due to poor alignment of polar axis
telescope (not polar alignment itself), and lack of focusing skills for
digital camera lens.
73P Schwassmann-Wachmann
component C, 2006 May
3.7073UT
73P Schwassmann-Wachmann
component B and
M13(left),
2006 May 3.6784UT
Common data: Canon 20Da,
EF200mm F2.8 (F2.8), three minutes exposure, ISO 800, Takahashi Sky
Port
portable equatorial mount. Images were cropped.
After taking photos, I observed
a series of this comet.
I could barely observe 73P Schwassmann-Wachmann C with naked eye, but
could not 73P-B. 73P G was very diffuse, though 13th magnitude, and
just the limit for my instrument (18 inch). I have to turn the azimuth
axis
of my telescope 180 degrees for a short time during the observation of
this comet, since it had just passed the meridian near the zenith! It
was
hard work and for me this was the first experience. I also tried 73P R
but
I could not.
After observation, I began to comet hunting at 2am and finished at
3:30am. Today is a national holiday and I can have enough time to sleep
after dawn.
Thu Apr 20
Whizzing wind woke me up at 1:50am. The sky was clear. I hesitated
to comet hunt with 18 inch telescope because of the strong wind.
However, it seemed to be weaker with time and I decided to assemble my
18 inch.
The sky was bright due to last quarter moon and the southern wind was
dry and warm. I started search from Gamma Cygni toward north.
Scintillation was extremely bad and it must be caused by the strong
wind in the upper air. The star images were distorted and looked fleshy
that made this comet hunting session uncomfortable: each star looked
like a comet.
Suddenly, at a quarter past 3am, scintillation became much better.
How easy and cool to search! The sky area I covered this predawn
included
the position of C/2006 A1 Poimanski that must be reduced to 10th
magnitude, but I could not catch it due to twilight and moon light.
Fri Apr 13
Kazimeras Cernis, a Lithuanian comet hunter, sent me a copy of book
written by an American comet hunter Don Machholz entitled “A decade of
comets: A study of the 33 comets discovered by amateur astronomers
between
1975 and 1984”. I exchange email with him every now and then but
it
came unexpectedly.
It consists of 111 pages, including description on the time,
magnitudes, positions, the statistics of discovery and orbital
elements. Tsutomu Seki had ever written similar booklets in Japanese,
though some Seki’s books features spiritual point of view; they are
fable rather than scientific reports. I guess his literature was not
known in foreign countries, unfortunately. Those kinds of publications
often feed and encourage comet hunters. Actually, I was one of them. If
it were not for Seki’s book, the number of Japanese comet hunter would
be much less.
A copy of Machholz’s book.
Sat Mar 25
I was ready to comet hunt at 2:45am but before it, I observed 73P
Schwassmann-Wachmann component B that was darker than the main
component C. The result is cited here. I could not notice the
component C at 68x and increased magnification up to 170x. Then, it was
apparent at a first glance. After brightness measurement, I changed
magnification to 68x again. Now, the component B was easy to observe
with 68x. To find a known deep sky object or a comet is one thing; to
discover unknown one is another.
Howt graceful the component C was! The tail was 6 arc minutes in
length that was the same with the component B. But I must make it a
snap. I just watched it and soon after that began to comet search.
It took 25 minutes to observe 73P that was long time for a comet
hunter at predawn. I always hesitate whether I really should observe
comets
or not, especially when I conduct brightness measurements because it is
time consuming work. However, regardless of doing brightness
measurement
or not, I never regret to observe a graceful comet that gives me an
impression of subtle and profound.
Sat Mar 18- Sun Mar 19
I attended the
36th Annual Comet Conference in Nishiharima
Astronomical Observatory, Western Japan, where 2 m (79 inch)
telescope, Nayuta, had the first light last year. This is the largest
telescope at home.
The Conference began in Saturday afternoon and closed at Sunday
noon. There were 44 attendees including both professional and amateur
cometary astronomers. The Conference consisted of 8 oral presentations,
4 sectional meetings and 73P Schwassmann-Wachmann session.
The opening statement by the chairperson of the Annual Comet Conference
management committee, Jun-ichi Watanabe of National Astronomical
Observatory Japan. Far left: the chairperson of Local Organizing
committee, Atsushi Mori of the Nishiharima Astronomical Observatory.
Unexpectedly, I was the only
comet discoverer among the attendees and was assigned to the chairman
of the sectional meeting on the comet hunting, in which 11 persons
attended. Six out of 11 attendees including me are active comet
hunters. On top
of those six hunters, one is planning to start comet searching and
making
a comet seeker, and another may resume hunting.
Two hunters are searching comets with DSLR (Digital Single Lens
Reflex) camera or CCD and others are visual comet hunters. There are
two Fujinon 15 cm binocular users, one Miyauchi 14 cm and Nikon 12 cm
binocular user, respectively. Others are reflector users but some use
both a binocular and a reflector.
For most hunters light pollution is a serious problem and they make
much effort to compensate for it; one said that he drove two
hours to
the observing site. Another remarked that he had supper and took a bath
and
then drove to the observing site to sleep in his car and got up at
predawn. After his comet hunting session, he heads for his office to
work!
Photographical hunters, especially CCD users have an advantage that
they can comet hunt under moderate light polluted conditions.
Yukio Sakurai who has discovered many novas shifted from a film
camera to a DSLR. He said that it is easy to take photos with DSLR and
he took a lot of images but it is time consuming to check all the
images.
Most of the comet hunters without discovery are unknown and you
do not know how many hunters in this country. Some people say there are
about one hundred active comet hunters in Japan, and I think it
is
reasonable judging from the number of hunters attended this Conference.
The next year’s Conference is held in Niigata Prefecture, and I
was assigned to the chairperson.
2 m telescope, Nayuta with me
This telescope is “photo visual” and we could observed Moon, Jupiter
and 73P Schwassmann-Wachmann through thin cloud.
Domes of 2 m telescope
Nayuta, and 60 cm reflector (far right).
Sun Mar 5
It is bright! At last I could observe C/2006 A1 Pojmanski at this
predawn.
Yesterday, I got up at 2:30am and 3am but was clouded out. Then, the
clear sky spread after sunrise yesterday and has continued since
then.
Today, before comet hunting I observed 73P/Schwassmann-Wachamann 3 and
P/2004 VR8 LONEOS. 73P was 12th magnitude and the tail was apparent
with 18 inch 68x, while VR8 was only 14th magnitude and at a first
glance with 68x I was not sure if the image I focus on was actually the
comet. I confirmed it with 157x.
Seiichi Yoshida observed both 73P-C/Schwassmann-Wachmann 3 as magnitude
of 12.3 and 73P-B/Schwassmann-Wachmann 3 as magnitude of 14.4 but what
I observed was 73P-C. I had not prepared the finding chart of 73P-B.
OK, I started comet searching session at 3:30am but there was thin
cloud at the low altitude and the transparency was not very good. The
rating was 3/5 when 5 is perfect. My telescope was trained at some 10
degrees south of Altair and I swept the sky vertically so that I could
catch C/2006 A1 during the session. After detecting NGC6781, no comets
like
objects were observed after a while. Suddenly bright comet crossed the
field
with a straight tail!
The length of the tail, type I, was about 2 degrees and there was the
type II tail at the position angle of a few tens of degrees clockwise
from the type I tail. The type II tail was very short and looked like a
part of the coma that was ejected. I could also recognize the type I
tail
by a 8x50mm binocular.
After I enjoyed C/2006 A1 cloud in the eastern sky become thick and I
took 10 minutes break. I found there was cloud gap at Soc and swept
there. I completed the session at 5:20am.
Sat Feb 25
Impressive predawn!
The first half of today’s comet hunting session I caught one dozen of
globular clusters in Scorpion and Ophiuchus, and the latter half I
enjoyed splendid star field in the Summer Milky Way in Cygnus.
I had set an alarm clock at 3am, two hours before the beginning of the
twilight, but I wake up at 2:25am. I drove to the usual observing site
where snow depth reduced to acceptable level. Just after one hour of
getting out of bed, I completed assembling my 18 inch telescope and
began
to search from M4, Scorpion. A lot of globular clusters that I met
welcomed
me for a long absence.
A few minutes after 4am, the light in a ski field had turned on that
caused serious light pollution in the south-eastern sky. Skiers
from Tokyo Area come to ski to this area at predawn.
I trained my telescope to the north-east and continued to search: the
Summer Milky Way in Cygnus touched me, too. Venus and the crescent Moon
rose and some time after the twilight began, I tried to observe
C/2006 A1 Pojmanski. However, the mountain near the horizon intercepted
the comet. Instead, I enjoyed Jupiter with a binoviewer and was also
impressive
like all the objects I observed this predawn! Apparently, observing by
two eyes reveals more details of Jupiter than by a single eye.
Fri Feb 10
Temperature was -9 degrees in Celsius. I began to comet search at 4:40
am, 20 minutes before the moon set and 30 minutes before the beginning
of the twilight. The summer constellations rose already in the
eastern sky.
I could comet hunt only once last month due to tight schedule, heavy
workload and snowy weather. On January 30 the sky condition for comet
searching must be excellent but I was in Nagoya area to give scientific
presentation as a forest hydrologist. Since last comet hunting session
I had gotten up at the predawn a few times expecting clear sky, but in
vain.
That blank makes today’s hunting session impressive, even though some
globular clusters I saw in Ophiuchus was not well resolved and stars in
the star ground in Sagittarius never looked pinpoint image because of
low altitude and poor scintillation.
As twilight proceeded the Summer Triangle rose in the northeast and I
completed the hunting session after Venus crossed the field.
C/2006 A1 becomes bright in the Southern Hemisphere. In my opinion and
I believe most agree with me, the naming of C/2006 A1 “Pojmanski” is
inappropriate in reference to the discovery story. It should be
named ASAS (The All Sky Automated Survey).
Thu Jan 12
The Disaster Relief Act was invoked in my city and surrounding area
about a week ago. At the elementary school next to my office Japanese
Army (formally called the Self-Defense Force) removed snow cornice
on the roof. I thank them for their activity again: they came to my
city
about a year ago for the rescue activity of the Mid Niigata earthquake
in 2004.
Tue Jan 10
Yesterday, clear sky spread and luckily, it lasted until this morning!
Off course, this is my first comet hunting session this year.
Temperature: -8 degrees Celsius. I decided to comet search in front of
my house on the snow where a snowplow pushes snow out to a paddy
field.
It took a lot of time to assemble my telescope and to prepare hunting
under such low temperature on snow. In addition to that, digital
setting circles did not work well; I tried to fix stars twice by aiming
at Spica and Polaris but indicator showed error messages. I wandered if
I got back my house and replace the digital setting circles with
extra one. At the next moment, I found Vega at low latitude and tried
to do again by combining Vega with Spica. This time it was OK! What a
relief!
I began to comet hunt at 4:20 a.m., one hour after I got up. After a
while, dew, caused by my breathing, condensed on the eyepiece and I was
forced to wipe it. Then, I powered the heater up than usual and after
that it never occurred: Kendrick
Dew Remover System is equipped on the flip side of the secondary
mirror, eyepiece of the 2 inch finder and the eyepiece of the18 inch
telescope.
When the eastern sky got brighter, I noticed the whole telescope looked
white because of frost. I could enjoy one and half hour hunting
capturing a dozen of deep sky objects.
Sun Jan 8
I went to usual observing site today not for comet hunting but for
check the sky visibility (Photo 1). You see a crash barrier rope on the
left of my car, which I dig out with a shovel. In normal winter I can
observe near the horizon from this hill slope site. Now snow depth is
3.5 m (11.7 feet) and it hides up to 20 degrees sky from the horizon. I
do not want to comet hunt at this site now.
Photo 1
Observing site with 3.5 m (11.7 feet) snow.
Cold wave still prevails nationwide and a record snowfall is observed
in a lot of observing points. The chance of comet hunting seems scant
this winter, especially here in Japan Sea side.
Snow depth in my city, Tohkamachi (or Tokamachi), has reached 3 m
(10 feet, Photo 2-4) but this value itself is not surprising: The
highest one was 425 cm (14.17 feet) that was observed in 1945. The
problem is that it is too early and that it must increase from
now on.
The snow depth chart from 1917 to 2005 in Tohkamachi (observed at my
workplace) is available here
(pdf file) and the latest snow chart is here (lower
right).
Photo 2
A girl has crossed the road and ‘enters’ a sidewalk. If it were not for
snow, it would have been mere sidewalk; however,
she has to enter there due to snow. Taken on Jan 7.
Photo 3
A man is walking on a pedestrian crossing. The snow wall in this photo
is the same with Photo 2 but it became higher. Taken on Jan 8.
Photo 4
A snow cornice on the building developed and seemed dangerous. Snow on
the shopping arcade and a city house was plowed many times but a
ferro-concrete building does not. Now snow weight is 800 kg/m2 that is
approaching to the structural limit for the ferro-concrete building,
990 kg/m2.
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