Major !!!!Comet outburst!!!!!

[Dave Lillis]

I had a good look at this comet through the 12" tonight and decided to put the canon on the back of the scope and try get a pic or 2.

This is 300k, so sorry in advance to our dial up friends.

http://farm3.static.flickr.com/2149/181 ... 7bb5_o.jpg

This was a 20 x 2 min exposure run (iso 800) with 3 discarded so 17 were stacked in registax, the images were full resolution for the camera and brought down to a more manageable size after processing was done.
You can see a gap in the star trails, that is where the discarded pics were. This is a full FOV image with the canon+12", I even used a dark frame. The central point was clearly seen as was the coma in this pic.
There is the makings of a tail to the lower right as the outline becomes diffuse compared to the upper left.
This was a very tough image to process without getting the onion effect gradients appearing in the coma, I don't know if you see that effect with your monitor, the comet is fairly smooth on my monitor, although the jpeg compression does put very faint colour ovals in there. The bmp version of the image was silky smooth.

All the same, I've never seen a comet quite like this one.!

[Frank Ryan]

WOW Dave!
That is a FANTASTIC image.

I can't see and onion effect, it's totally smooth.
The balance is perfect and you can just see the streamers in the tail without
going over the top in pushing the levels.
The startrailing gives a lovely sense of movement and scale.
It's well positioned too.

Do yourself a favor and send it into the Mags!!!

[John O'Mahony]

Awesome picture Dave

[DaveN]

Wow Dave..

Great shot !!

[John O'Mahony]

I managed to get a brief look at the comet last night just as a break in the cloud cover appeared through my 3". I was surprised just how bright. not to mention large it was. I thought I could detect a faint tail but then the clouds moved back in.
ps did anyone catch Venus and the Cresent Moon ths morning - quite spectacular.

[Frank Ryan]

ps did anyone catch Venus and the Cresent Moon ths morning - quite spectacular.

Sure did John!
See here:

http://shannonsideastronomy.com/phpBB2/ ... c.php?t=86


As for Holmes.
I've been observing it closeley since the outburst (weather permitting)
and I am now convinved there is an elongation visible.
Not tail as such (as seen in the long exposure shots on the net)
It is for sure getting bigger each night.
Not a bright lately in the last few days but the size makes up for it!

Here is a quick shot I took through the Clubs 12'' using eyepiece projection (for anyone else that means sticking the camera lens
up to the eyepiece and popping off a shot)

I have yet to get a proper shot of this beauty because the weather
has pipped me to the post on every occasion.
(except last night, when there was the perfect opportunity as there was
a power cut from Ballysimon all the way out to Boher!!!! arrrrraagghh!)

[DaveN]

Hi guys,

Managed to find holmes for myself tonight.
Once I found a star chart listing its current position (Stellarium didn't have it), I stuck my head out my bedroom window and actually managed to spot it even with full street lights in the estate !!!

It was quite obvious that there was a fuzzy ball just to the left of Perseus even with the poor lighting conditions.

To be sure I wasn't imagining it, I took a trip out the road to somewhere darker. In those conditions it was even more obvious. I took a look at it with my rather poor binoculars and could clearly make out the fuzzy shape next to the pinpoint stars. I wasn't able to make out any definition to the nucleus but it was certainly worth seeing. It certainly is a very unusual object!!

B.T.W. Keep the photos coming guys, they are really spectacular!!

Cheers,
Dave

[DaveN]

I have just realised that you can add new objects into Stellarium by editing a text file with the orbit description.

I found a website with the following instructions for adding Comet 17P Holmes to Stellarium,

This assumes you have a default installation of Stellarium Version 0.9.0

1. Close Stellarium if you have it open.

2. Using notepad open the file:
"C:\Program Files\Stellarium\data\ssystem.ini"

3. Scroll down to the bottom and copy/paste the following section into the file

[17P/Holmes]
name = 17P/Holmes
parent = Sun
radius = 1000
oblateness = 0.0
halo = true
color = 1.0,1.0,1.0
tex_halo = star16x16.png
tex_map = nomap.png
coord_func = comet_orbit
orbit_TimeAtPericenter = 2454225.0277
orbit_PericenterDistance = 2.053218
orbit_Eccentricity = 0.432564
orbit_ArgOfPericenter = 24.2712
orbit_AscendingNode = 326.8646
orbit_Inclination = 19.1126
orbit_SemiMajorAxis = 3.617468
lighting = false
albedo = 1
sidereal_period = 2578.665

4. Save the file and reopen Stellarium.

You should now see Holmes next to Perseus. (at least in Nov '07)
I can't vouch for the accuracy of the above details but I can tell you that it correctly predicted the location of Holmes on 8-Nov-07 @ 23:00

Hope this helps.

Dave

[Dave Lillis]

Fair play Dave for hunting down the comet and having a good look at it !!
Hopefully if its clear this weekend, the club will have an observing session and head for the hill and get a good look at it.

[Conn Buckley]

I got this image last Thursday 8th Nov. It is a 49 Sec. exposure which managed to capture the background stars before trailing started. I liked that it caught the different star colours even though the Comet is not exactly centred. But, more inportantly, even if the comet was centred its outer edges would have been just outside the field of view. Previous images which I have posted have the comet comfortably within the field of view and these were of 6 secs. exposure It is a measure of just how big it has become and how diffuse. Conn

[Conn Buckley]

From the various images captured on Thursday 8th Nov. I wondered if I could see how much the comet had moved. This image is actually two images stiched together, each taken at separate times with the same scope/camera set up on the same night.
From this zoom image you can see how much the comet moved relative to the distant background star (at the 7 o'clock position) in the space of 1 hr. 15 mins 3 secs. Conn

[John O'Mahony]

Great images Conn. Well done

[Dave Lillis]

Great images Conn, it really is great to see how big this comet ha become over the past few weeks.
As far as speed goes, this comet is going at an absolute crawl compared to your average comet.