17P / Holmes - OCT 31, 2007

| 2 Comments

Step 1
Move mouse over sketch above to view labels. Click image for larger version.

Step 1
Move mouse over sketch above to view labels. Click image for larger version.

Observation Notes:

After a couple days off from observing the comet, I was treated to more stunning views. The moon was out of the sky, and Holmes was really showing its stuff. To the naked eye, it is a soft puff in Perseus. Through 15 x 70 binoculars, it is simply awesome, floating brightly amid a rich star field. Color is now hard to describe, but I think it looks like the most subtle aqua color. Through the telescope, it is wonderfully bright, and loaded with soft detail. The subtle outer halo makes the comet appear even brighter than it is, as though the radiance of the coma is lighting up its surroundings. The outer halo appears brighter to me along the southwest side. The coma sports a well-defined northeast side with a diffuse southwest edge. Its edges have a hairy appearance that looks like it is being blown gently to the southwest. Within the coma, the central condensation now looks detached from the pseudonucleus. Some very subtle radial features began to coalesce after 45 minutes of observing at 120X and 240X. I don't know if these are real structures, or just the cometary version of Martian canals. A brighter jet seemed to connect the now faint pseudonucleus with the detached condensation.

My measurements with the astrometric eyepiece are as follows:

  • Central Condensation: 92 arc seconds / 1.5 arc minutes
  • Coma: 653 arc seconds / 10.9 arc minutes
  • Outer Halo: 1550 arc seconds / 25.8 arc minutes

Subject17P / Holmes
ClassificationComet
Position*6:15 UT - Perseus: [RA: 03:45:52.4 / Dec: +50:32:29]
SizeCentral condensation: 92 arc seconds / 1.5 arc minutes
Coma: 653 arc seconds / 10.9 arc minutes
Outer halo: 1550 arc seconds / 25.8 arc minutes
Brightness*~ 2.6 vMag
Date/TimeOctober 31, 2007, 10:00 - 11:30 PM
(November 1, 2007, 05:00 - 06:30 UT)
Observing Loc.Flagstaff, AZ - Home
InstrumentOrion XT8 (203 mm dia./1200 mm F/L)
Eyepieces/Mag.25 mm Sirius Plössl (48X)
10 mm Sirius Plössl +/- 2X Barlow (120X/240X)
12 mm Meade Astrometric +/- 2X Barlow (~100X/200X)
ConditionsClear, calm
Seeing3/10 Pickering
Transparency~ Mag 5.8 NELM
*SourcesAerith.net; Starry Night Pro Plus 5

*Based on published data.

2 Comments

Jeremy,

This is one of the most accurate sketches of Comet 17/P Holmes I have seen yet. Very nice!

~WadeVC

Wade, thanks! I've been enjoying your sketches of the comet as well.

Leave a comment

You do not need to sign in or register to leave a comment.


The Cerulean Arc

My weblog for
everything else non-astronomy

Pin at will!


(Thanks for maintaining
return links.)

About this Entry

This page contains a single entry by Jeremy Perez published on November 1, 2007 4:17 AM.

17P / Holmes - How big will it get? was the previous entry in this blog.

17P / Holmes - NOV 3, 2007 is the next entry in this blog.

Find recent content on the main index or look in the archives to find all content.

Categories

Monthly Archives

Powered by Movable Type 4.23-en