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

Conn Buckley · Post by **Conn Buckley** » Thu Oct 25, 2007 7:30 pm

I do not know how many people see Terry Mosely's newsmail but the following has just arrived.

"MAJOR!!!! COMET OUTBURST!!!!
From: TerryMosel@aol.com
Add contact
Sent:24 October 2007 23:17:19
To: iaa2000@btinternet.com
Hi all,

This is hard to believe, but I've seen it with my own eyes! I've just come from an IAA Council meeting (bad timing!), but I saw the comet with binocs in twilight before the meeting, and easily with the unaided eye afterwards, from Belfast! Here's the story......

Comet 17P/Holmes is undergoing a major, spectacular eruption. The 17th-magnitude comet, which is now at 'opposition', has brightened by a factor of five hundred thousand or more during the past 24 hours becoming a naked eye object in the evening sky. This may signify a break-up of the comet's core or a rich vein of ice suddenly exposed to sunlight - no one knows. Look for a yellow 2.5th-magnitude starlike fuzzball in Perseus after sunset. ("2.5th magnitude" means a little dimmer than the stars of the Big Dipper.) At present the comet looks more like a star than a comet, because only the nucleus has brightened - it does not have a discernible tail, but it might grow one as the outburst continues.

Tonight it lies close to the star 43 Persei, about 5 degrees East of Alpha Persei. To locate it, take a line from Alpha Persei to Delta Persei, then left at 90 degrees to that line for about 2/3 of that distance - you'll see a bright 'star' that should not be there - that's the comet!!!!

At midnight tonight (24/25 Oct), it's at RA 03h 52m 57.9"; Dec + 50 deg 08m 10.6".

Tomorrow night (24h) it's at RA 03h 52m 05.0"; Dec + 50deg 12m 34.0"

If you have a computer programme, the elements are:

Epoch: 2007 May 20.0 TT.
T = 2007 May 4.4995 TT
q = 2.053169 (2000.0)
n = 0.1432508
a = 3.617468
e = 0.432429
i = 19.1132
P = 6.88

(Peri = 24.2585; node = 326.8675)

This is an absolutely amazing outburst, and you should see this object if at all possible - no-one knows what will happen next.

Clear skies,

Terry Moseley

Visit http://spaceweather.com for a sky map, photos and updates.

John O'Mahony · Post by **John O'Mahony** » Fri Oct 26, 2007 8:27 am

Hi Conn

I managed to get a quick look at it throught the Lidl 10x50s last night around 10pm. Easy to mistake it for a bright star unless you knew there was a comet around but I could see a slight halo (like a diffuse globular cluster look like in binos) that was quite obvious. Didn't get a chance to use the scope on it though due to other committments

Dave Lillis · Post by **Dave Lillis** » Fri Oct 26, 2007 11:22 am

Frank and I headed to Doonbeg in Clare last night, a fantastic site illuminated only by the moon.

We had a good look at this comet through the 20", there is definitely a steller like nucleus with a fan shaped wedge mini tail completely contained within the coma, the coma had a very definite outline with one side of it been definitely fuzzier then the other, the side with the mini tail, maybe this is the starts of a dust tail emerging ? this thing really looks like it is heading towards us Laughing
To me, the outer area of the coma looks a little more intense then the area of the coma halfways between the centre and the edge, almost like a shock wave.
I reckon that given the illumination range of this thing, it will be difficult to get an image that represents the visual view through a scope

Frank Ryan · Post by **Frank Ryan** » Fri Oct 26, 2007 8:32 pm

Sweet!
First images of a comet!

Taken Wed 24th around midnight with the ETX125PE.
Phillips Spc900 webcam (no barlow)

Here's a wide angle shot from thes same night....

[/url]

It's not showing up on the bigger image but I can see a darker area in the core..

Dave Lillis wrote: I reckon that given the illumination range of this thing, it will be difficult to get an image that represents the visual view through a scope.

Well, here is a stack of 13 separate shots taken by Dave & I last night the 26th of October from Doonbeg through the
20'' With a Canon 350D using various exposure and iso settings.
All the images and the resulting stacked image I have left unprocessed.

I think it gives a very good impression of what we saw through the scope
but it doesn't show the pin point nucleus that is so evident in the wide angle eyepieces.

The impressive thing was to see the pin-point background stars around it
which gave fantastic contrast to the size and fuzziness of this amazing comet.

John O'Mahony · Post by **John O'Mahony** » Sat Oct 27, 2007 8:03 am

Nice images Frank.
Looks like the weather is against us for the next few days.

Frank Ryan · Post by **Frank Ryan** » Sun Oct 28, 2007 10:45 pm

Lads and Lassies, it looks like its getting bigger and brighter for sure!!!
(based on tonights observation anyway)

Conn Buckley · Post by **Conn Buckley** » Mon Oct 29, 2007 6:37 pm

I know that there are now thousands of images available , but here's my humble effort at imaging what looked to me like a 'motorbike coming at you in a fog'.
I agree with what many have already said i.e. that no image has recreated the impression at the eyepiece. I have had no opportunity to have a look since last thursday but images made by others are very impressive.

Frank Ryan · Post by **Frank Ryan** » Mon Oct 29, 2007 8:25 pm

Wow Conn thats class.
How did you photograph it?
(your 'humble' image is as good as I've seen anywhere! - you should post up more!)

Conn Buckley · Post by **Conn Buckley** » Mon Oct 29, 2007 10:29 pm

Comet Holmes at 8;30pm on 29th Oct. Much bigger object and this time its position has some stars to give it some perspective, even if the focus is not spot on. Any suggestions on how to get the focus exactly right? The article in this months Sky and Telescope gave the answer albeit an expensive one.

Conn Buckley · Post by **Conn Buckley** » Mon Oct 29, 2007 11:31 pm

Tried to put the two images I have together. Both images were taken with the same settings at 8:30pm -- the first was on 25 Oct and the second on 29 Oct. Am I not understanding something here or has it actually changed that much in just 4 days?

Frank Ryan · Post by **Frank Ryan** » Tue Oct 30, 2007 12:32 am

WOw! Conn, they are fantastic!

The comet has grown in size for sure...
Check this animation out on Spaceweather..

http://www.spaceweather.com/archive.php ... &year=2007

I can see the change even with the naked eye now.
What an awesome comet!

Dave Lillis · Post by **Dave Lillis** » Tue Oct 30, 2007 2:34 pm

humble??, you gotta be kidding me, that's a great image !!
If the camera and adapters are the same then the 2 pics are to scale, reports have come in that this thing has expanded alot , to me it now looks quite diffuse to the naked eye, it wasn't like that on Thursday.

you should post that in the Comet Holmes thread on the IFAS site.
http://www.irishastronomy.org/boards/vi ... php?t=7271

John O'Mahony · Post by **John O'Mahony** » Wed Oct 31, 2007 3:36 pm

Great images Conn

What camera did you use?

Conn Buckley · Post by **Conn Buckley** » Wed Oct 31, 2007 7:52 pm

John, Canon EOS 400d bolted on to the LX200R 10" for about 6 seconds. I do not have a lap top , so carrying the desktop outside to use the webcam is a lot of bother especially when the weather was dodgy.
I had one of those 'Hommah .. Hommah ... HOMMAH moments the other night. I leave the scope on the tripod and carry the lot down a few steps out through the conservatory to the back of the house, Anyway, I had everything out, power lines everywhere and the scope tracking nicely with camera attached-- ready to race and I felt the rain arriving.

So, I grabbed an old parasol and covered the lot pondering what to do next!! Fortunately the rain stopped just as quickly as it started.
What is it about halloween time? In 2003 I saw and photgraphed my first sunspots with my ETX 90 and within a few more days I had seen not one but 2 aurorae -- now Comet Holmes.
Any luck with observing /photographing Holmes? Conn

John O'Mahony · Post by **John O'Mahony** » Wed Oct 31, 2007 8:35 pm

Conn Buckley wrote: Any luck with observing /photographing Holmes? Conn

I managed to get a look at it a few days ago through the 8" sct and my 3" short tube refractor (which I have on standby in case of a break in the clouds). I thought the comet looked assymetric suggesting we may see a tail when the line of sight is better (orbit shifts a bit). The weather is too iffy to set up the 11" but to be honest the 3" refractor showed just as much (due to the glow from the moon) and only takes two seconds to move outside.