Comet Garrad C/2009 P1

Got a question on astronomy that you'd wanted to ask? Ask your questions here and see if the old timers can give you some good answers.
Post Reply
User avatar
rcj
Vendor
Posts: 2983
Joined: Sun Sep 28, 2003 1:46 am
Location: Katong
Contact:

Comet Garrad C/2009 P1

Post by rcj »

Hi all,

Been quite a while since we last saw a nice comet. Here's one which may hold some promise and located in an area of the sky away from the sun's glare - Garrad C/2009 P1.

It is currently in the constellation of Pegasus at magnitude 8.2, with a 9' coma. It is expected to brighten by 0.7 magnitudes, and gradually moving towards Sagitta/Aquila region end of this month. At this magnitude, it is possible to already image it with our DSLRs in semi-dark skies.

Finder chart can be seen
here.

Have fun!
Photon Bucket
http://www.celestialportraits.com
Facebook page: celestialportraits

User avatar
Tachyon
Posts: 2034
Joined: Wed Jun 01, 2005 11:40 am
Location: Bedok

Post by Tachyon »

Yes, I have been following it with the RASO.

This was taken on 1 Aug, exposure 5 mins:

Image
[80% Steve, 20% Alfred] ------- Probability of Clear Skies = (Age of newest equipment in days) / [(Number of observers) * (Total Aperture of all telescopes present in mm)]

User avatar
starfinder
Posts: 1038
Joined: Tue May 25, 2004 11:15 pm
Location: River Valley / Tanglin Road
Contact:

Post by starfinder »

Thanks Remus for another lead!

I took some images of the comet this evening.

Here is one taken at 9:53pm (5 Aug 2011 1353UTC)
Position at: RA: 21h 20m 43s Dec: +13°45'33" (Equatorial 2000)

Imaging details: Meade LX-90 8"SCT f/10. Canon EOS60D, 20s, ISO 800.

Immediately below is the original image, full field of view.

Below that is a screen capture of The Sky6 software showing roughly the same field of view as the camera. From the pattern of the stars, we can see that the field of view matches.

So the identity of the object as Comet C/2009 P1 (Garradd) is I think confirmed. However, I hope to take another image soon to see if the comet's movement can be detected.

The reference star is SAO 107049 of mag 8.73.
According to the BAA's Comet Section, the comet's magnitude is now around 8.5:
http://www.ast.cam.ac.uk/~jds/


The third item below is the same image at 100% (cropped).

Visually, I thought I may have seen the comet through the eyepiece just now, but not certain. Will try again to confirm.

Image

Image

Image

User avatar
starfinder
Posts: 1038
Joined: Tue May 25, 2004 11:15 pm
Location: River Valley / Tanglin Road
Contact:

Post by starfinder »

I can now confirm that there is no doubt it is the comet, for the image below (20s at ISO1600) shows that it has moved quite a lot. In the words of Galileo, "Eppur si muove".

This was was taken at 11:07pm local time (1507UTC), i.e. 1 hr 14 mins after the first one.

Using the planetarium software, I estimate the movement to be about 2 arc minutes based on a comparison of the distances of the other stars with each other.

I also attempted another visual observation of it. I used a 14mm eyepiece, for about 143x power. I am confident that I did indeed manage to observe the comet from here in central Singapore. This was with direct vision. The object looked different from the surrounding pinpoint stars (around mag 9 to 10), as it was diffuse but with a brighter core. It is not bright or obvious, but once seen it is clearly there.

For the record, the comet was in the constellation Pegasus, near the border with Equuleus and Delphinus, and not too far from the globular cluster M15.

Now, let's hope it brightens, and not just moves.

Image

User avatar
rcj
Vendor
Posts: 2983
Joined: Sun Sep 28, 2003 1:46 am
Location: Katong
Contact:

Post by rcj »

wow you guys are fast! brilliant! still waiting for my camera.... today's weather looked good too.
Photon Bucket
http://www.celestialportraits.com
Facebook page: celestialportraits

User avatar
starfinder
Posts: 1038
Joined: Tue May 25, 2004 11:15 pm
Location: River Valley / Tanglin Road
Contact:

Post by starfinder »

Ok, I've made a side-by-side montage of the same two frames.
As I was using a alt-azi mount, I had to rotate the 2nd image to the exact same orientation as the first one, and then cropped the two to have the exact same rectangular field of view.

Now the comet's movement in just over an hour can clearly be seen.
(Edit: I've boosted the brightness of the frame on the left (taken at ISO 800) to make the stars near the comet easier to see and also to be similar in brightness to the frame on the right (taken at ISO 1600))


Image

User avatar
Gary
Posts: 3790
Joined: Tue Sep 30, 2003 7:06 am
Location: Toa Payoh
Contact:

Post by Gary »

Great stuff Gavin! It moved!
http://www.astro.sg
email: gary[at]astro.sg
twitter: @astrosg


"The importance of a telescope is not how big it is, how well made it is.
It is how many people, less fortunate than you, got to look through it."
-- John Dobson.

User avatar
Airconvent
Super Moderator
Posts: 5628
Joined: Tue Sep 30, 2003 11:49 pm
Location: United Federation of the Planets

Post by Airconvent »

Great effort Gavin. Always amazed at your energy!
Its so convenient to have a good balcony and an LX90...haha.
Do keep on capturing it as it grows brighter! [smilie=cute.gif]
The Boldly Go Where No Meade Has Gone Before
Captain, RSS Enterprise NCC1701R
United Federation of the Planets

Post Reply