October 29
Comet Levy fading away
What has become of weather recently! It is late October but
so hot. As the sun has shifted southward, strong sunlight gets directly
into my study and I still have to keep air-conditioning going everyday.
On my way to the observatory today, I turned on the air-conditioner in
my car. The temperature in the dome stayed around 25 degrees C through
night and I observed wearing a short-sleeve shirt until morning. Occasionally,
I saw fast-flying fireballs with long trails. The Taurid meteor shower
may be active now.
I spent a lot of time sweeping the sky near opposition using
the 60cm reflector. I also searched from my third observatory with a roll-off
roof. Alongside the telescope a meteor patrol was going on with 35mm cameras
alongside. My observing session involves two or three simultaneous activities
like this. During a typical observing session I would shuttle between the
two domes 30 meters apart many times, which gives me quite a lot of physical
exercise.
My search using an altazimuth mounting has been made easier
by the use of digital setting circles purchased from Magellan about 3 years
ago. Without the digital setting circles, there is no way to know RA and
Dec. coordinates of the object you are watching, as a comet seeker was
on an altazimuth mounting. When I was using 12cm Nikon binoculars, I obtained
the horizontal coordinates using the azimuth and altitude rings, then converted
them to equatorial coordinates to work out the position of the object.
In this method I could get measurements as accurate as by sketching, which
was quite reliable, but the drawback of this method was an amount of time
required. The digital setting circles are very small in size, but can display
the positions of the objects quickly. If the two-star initialization is
accurate, the position of the object is displayed with an error margin
of less than 10'. When more accurate positional measurement is required,
I will turn to the wide-field equatorial telescope sitting next to me and
take photographs of the object. Nothing is better than this arrangement.
This 21cm photographic telescope with a 5-degree-wide field will catch
the object without fail. When you find a "suspicious" object,
it is vital to work out its position even roughly, though it is not easy.
What was once very difficult now has become easy thanks to the technologies
in electronics. However, the development of technologies does not necessarily
mean increasing discoveries. Ultimately, dedication, energy, and perseverance
makes a difference.
After 7 long hours of observing, I turned the 60cm reflector
to Comet Levy (P/2006 T1) in the morning sky. It became fainter with a
small coma and looked as if it were just about to disintegrate. The total
magnitude was 12.5 and no tail was detected.
In the elongated coma there appeared to be two nuclei, one ahead of the
other. It made a good contrast with the round and well-defined coma of
C/2006 L1, which was visible in the same area. Comet Levy is fading from
the scene. I will photograph it one more night to determine its precise
positions. This comet seems to have begun to show deviations in an intricate
way from the calculated orbital elements due to non-gravitational effects,
but this will be in the domain of orbit calculators.
On my way down from the observatory hill I saw brightly shining
Orion and Canis Major through trees in the forest. It was an awesome sight
and I stood still on the sidewalk mesmerized by their unforgettable beauty.
Large, blue Sirius looked like the last bit of a sparkler dangling motionless
from the end of the stick. It didn't move even a little, indicating the
atmosphere was quite stable. It was a perfect night for star-loving people.
