Heads up - NGC 5907 and Comet Siding Spring

[DarkerSky]

This weekend 13 - 15 March Comet C/2007 Siding Spring passes close to spiral galaxy NGC 5907. Could be a good opportunity to capture comet and galaxy in the same FOV.

Magnitudes:

Comet Siding Spring: Mag 10.9

NGC 5907: Mag 10.4

[John]

I managed to see both the comet and NGC 5907 tonight with my 10" newtonian but boy was it a tough challenge !.

The Heavens Above web site has Comet C/2007 Q3 Siding Spring listed as magnitude 10.9 (as Darker Sky states above) and it seemed every bit as faint as that to me. I used the Telrad finder and my 20mm Nagler to get to the right starfield but the small, very faint misty spot that was the comet only revealed itself when I used the 13mm Ethos - the additional magnification darkening the background sky slightly which helped. It was also confirmed with my borrowed 10mm Pentax XW and my 7mm Nagler but never more than right on the edge of visibility, needing averted vision and tapping of the scope lightly to confirm it. This was "at the limit" stuff for my observing location and the conditions but very satisfying to have tracked down this challenging object from my moderately light polluted back garden.

I stumbled upon the nearby galaxy NGC 5907 while panning around looking for the comet - at magnitude 10.4 it appeared as a thin needle of misty light. It was not in the same field of view as Comet Siding Springs, at least not in with the 13mm Ethos at any rate. I'll return for another look at this one in due course I think.

Only faint patches of light both of them but they have kept me entirely occupied for the past 2 hours and left me feeling a real sense of achievement

[Talitha]

Just got back in a while ago. I wanted to catch the comet before it was masked by magnitude 10.9 star HD 238452, so i needed to get it before midnight. We're in daylight savings time already (5 hour difference instead of 6), which means my observations were made at about 04:00 UT 15 March.

Despite the low altitude (38 degrees), the galaxy was easy enough. The comet was difficult though, on the verge of impossible. I finally nabbed it avertedly a few times but wow, it was tough. The scope used was an 8" SCT at 64x. Transparency was average (M101, M51 and M81/82 were all easily seen with the 11x70s).

If the sky cooperates tomorrow night i'd like to give it another try, maybe with the 120ST so they'll both fit in the fov. But it's almost certain that the loss of aperture will mean the loss of the comet.

[Doc]

Well done to both of you, it does sound like a very challenging, mag 10.9 is going to e hard to catch unless your skies are very dark.

Also John it's amazing how time flies when you have an objective like you had.

[NickH]

Have an image of the comet from last night...will post up soon

[John]

Have an image of the comet from last night...will post up soon

That would be great Nick

It would be good to know that I was not imagining things ! (or confirm that I was )

[John]

Just ... The comet was difficult though, on the verge of impossible. I finally nabbed it avertedly a few times but wow, it was tough....

I found this with my 10" as well - I felt that the quoted magnitude was a bit optomistic to be honest - the comet seemed fainter than mag 10.9.

[NickH]

Images are now up...here's a few (with some rotational gradeint processing on the two tails)

Very nice comet indeed

Imaged with an Atik 314L/TMB105 F6.2

20 x 2 minute subs, locked on the nucleus, and then composited in the star field

[John]

Wow ! - what a lovely object. Needless to say it looked nothing like that through the eyepiece - the faintest haze of light was all I could make out visually. The starfield looks familliar though so I'm sure I was looking in the right place.

Thanks for posting the pics Nick

[NickH]

Ignore the date, that's just me copying and pasting from the IAU site (incorrectly a month out!)

[NickH]

New one. Composite of my comet data with the SDSS data for star colours.

[John]

Was the latest one taken before or after the previous one Nick ?. There is clear motion of the comet between the 2 images - at a guess I'd say, based on the 2 hours I spent observing it, that the 1st image you posted might have been captured after the one your latest post - but the comet was so faint it was difficult to tell TBH.

[Talitha]

Fantastic images Nick! I sure wish it would have looked like that in the eyepiece. Although the tail is a lot shorter, it reminds me of Bradfield's a number of years ago.

I checked the stats on the Comet and 5907 in Sky Tools 3. The surface brightness of the comet is brighter than the galaxy, so theoretically it should be easier to see... no idea why it's not, though.

Comet... Surface brightness: 21.6 Size: 2'

5907..... Surface brightness: 22.2 Size: 11' x 1.4'

[DarkerSky]

Stunning images there Nick. It's got quite an appreciable tail on it considering how far it is out now and abt 6 months after perihelion.

John / Carol - loved reading both your reports on this. I know what you both mean about it seeming fainter than the stated mag. I picked it up about 10 days ago when at Mag 10.8. I had to find it in a moderate power as I just couldn't pick it out from the background in low powers. The head is also rather small, so makes it more challenging. That night I did get a vague hint of a tail trailing off it, but only a vague hint

Shame it wouldn't go into the same FOV as NGC5907

I have found Mag 12 galaxies easier to pick out than this comet!

[NickH]

I did image 5907 at the same time, but it was (as you say) not in my FOV...a larger CCD would have got it

[mike.brightmore]

Beautiful images Nick. I know I'm a week late for the close encounter but I couldn't pick out the comet last night. This is how NGC 5907 looked in my short exposure retina.