Virgo Galaxy Cluster Observing Session

[astronymonkey]

On the very early mooning of Sunday 26^th March I was lucky enough to be at the Kielder Star Camp under a clear sky with my 16inch dob at hand.

My plan for the night was to get in a good haul of galaxies from the Virgo Galaxy cluster so using a Photographic Star atlas of the region with stars to Mag 16 and labelled galaxies to Mag 13 I began my observing.

Dew could have been a problem so I had the dew control on eyepiece, red dot, both ends of the finder and secondary mirror running at approx 50% with an Air Temperature of -1.1 Celsius.

I started the session from the 5^th Mag star 6 Com which is about 6 degrees east of beta Leo and this was visible to the naked eye so made a good starting point for my star hopping.

The Virgo cluster is absolutely packed with galaxies and I easily found that I could star hop quite easily between the brighter objects and then pick up the dimmer objects in between. With a 22mm Nagler T4 in the focuser for the full session I had a 0.97degree true field at 87x magnification which made star hopping easy.

My route around the cluster was to head north east from 6 Com up to M100 as far as NGC 4350 and 4560 and then moving back down as far as NGC 4206.

From here I began to make my way east via 4294 and on to Markarian’s Chain and sweeping back after reaching M91 and ending up at NGC 4568/4567.

The highlight of the session was definitely NGC 4568 and 4567 which are two colliding galaxies which appear as a butterfly shape and were worth spending some time observing. I also spent some time looking for the jet from M87 but nothing could be seen. Markarian's chain was also nice to see but at one point I moved over an area where there were 8 galaxies in the field of view which is something I haven’t seen before.

I also wanted to see what the limits of what I could see with the scope but from the chart I had most of the objects were easily visible with a few which were harder to see and needed averted vision, only one object I looked for wasn’t visible. I also noted what the faintest galaxy I could see was and then I had the chance to refer back to the magnitude charts to see what this would tell me.

Strangely the range of objects upto 12.6 could be seen clearly with those up to 13.3 needing averted vision. The object I classed as being on the limit was at Mag 12.4 which didn’t correlate well with being able to see some objects which were considerably dimmer. The single object I couldn’t see was at Mag 12.1 so I’m suspecting that this was an anomaly as it is well within the range of what I was observing.

I finished observing at 1.37am having spent about 45-60 minutes observing having had a successful haul of 49 objects.

The objects seen were:

Easy:

 

 M58, 84, 86, 87, 88, 89, 90, 91

NGC 4413, 4189, 4193, 4206, 4212, 4216, 4222, 4294, 4299, 4313, 4371, 4387, 4388, 4402, 4425, 4429, 4435, 4438, 4440, 4452, 4458, 4459, 4461, 4473, 4474, 4477, 4479, 4491, 4497, 4503, 4531, 4567, 4568, 4634

Faint:

 

IC 3476

NGC 3476, 4305, 4306, 4351, 4571, 4633

Very Faint:

 

NGC 4330

Not Visible:

 

NGC 4528

 

 

Cheers

[John]

Great report !

I'd like a night like that soon

[scarp15]

Great, very impressive hour, how did the Saturday night fair in terms of clear Sky, did you specifically wait until early Sunday morning for Virgo to culminate? I was out observing due east of Kielder until around 1.15am (not accounting for the clock change), occasional patches of thin cloud here and there but mostly clear with mostly very good transparency. I will have to refer back to former session notes to see if I have encountered NGC 4568 & NGC 4567, they have at least been on my 'radar' to observe and will note this pairing for next time.

  

[astronymonkey]

Hi Scarp

There was a bit of a milky haze due to the moisture in the air and some sky glow from Nescastle but the air was stable with no wind. For this reason i waited til virgo was high and away fron the Newcastle glow.

CHeers

[Knighty2112]

Great haul of galaxies. Well done!  Have to get to a good dark site myself one day. Managed to grab quite a few of the M's myself in Virgo on Saturday night with my 4SE Mak in my light polluted garden which I was surprised with! Wonder what I could get in a good dark sky like Kielder with the same scope? 

[astronymonkey]

I think with a 4inch mak you would be able to see a lot of the brighter objects and if you cover the wider coma virgo leo area then you would be able to get a reasonable haul. If you have tracking and goto then that would help too along with a decent star chat so you can confirm you are in the right  place.

A dark sky will also add greatly and this helps give some contrast to the dimmer objects that get lost in a light polluted garden.

Cheers