NGC 4098/VV61

[obrazell]

I was wondering if anybody here with the larger telescopes had managed to split the NGC 4098/VV 61 pair. The smaller galaxy appears to be quite close in and faint so I guess it is not going to be an easy split.

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Owen

[wvreeven]

I checked DeepSkyLog.org for observations of this galaxy and there are three. One by Steve, but I'll leave it to him to inform us about his observations. Two other observations were done with a C14 and a 40 cm dob and both report not seeing any detail in the galaxy. One does note the 12 mag star to the south south east (assuming the pic you posted has north up and west to the right).

[Jimi Lowrey]

Hi Owen cool galaxy. I am sure I have see it but can not find any notes about the two cores.

The Poss1 and poss2 photos look like it might be a tough one. The SDSS list it at 14.25 V mag but that may not be accurate due to it being embedded in a galaxy merger.

I will try it when the moon gets out of the way and let you know what I see.

[Steve Gottlieb]

I only have one observation from 30 years ago and recorded a single core ("fairly faint, fairly small, round, bright core"). I probably used 220x, but as the nuclei are separated by only 10", this is going to require higher power (and good seeing) to resolve. They certainly look bright enough, though. Here are a couple more observations.

Mark Bratton, mentions the dual structure in his Guide to the Herschel Objects, but he only noticed the "the brighter [northern] elliptical galaxy as an irregular patch of light which is brighter to the middle in a hazy, ill defined envelope." Also Piero Mazza, using a 16", just calls it "slightly elongated N-S, size 45"x30", gradually brighter towards the middle.", so didn’t resolve the nuclei either.

[Jimi Lowrey]

Here is the PanStarrs image of VV 61

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[Bill Weir]

Now another one I’ll need to reobserve. I logged this galaxy a year ago with my 20”. Smallish, fairly faint, brighter core slightly elongated NNW SSE. That’s it. THis split will require pretty steady skies I think. Also when I looked at this in SIMBAD I see a third object is noted as that SE section. This is on my list for next clear sky.

Bill

[Steve Gottlieb]

Bill, is the third object you're referring to identified as RASCALS NRGb177.088 in SIMBAD? Checking the original paper (redshift survey), their position (http://vizier.u-strasbg.fr/viz-bin/VizieR-6?-out.form=%2bH&-source=16070202&-corr=PK=RASSCALS&-out.max=9999&RASSCALS==NRGb177) is centered on the southern nucleus, so only two objects.

[Bill Weir]

Yes this is what I’m referring to so OK thanks.

Bill

[Jimi Lowrey]

I gave NGC 4098 a go last night under fair transparency and below average seeing. I found the other nuclei a tough nut to crack. I spent a lot of time on it and found that on this night 610X was the best power to see the twin galaxy's cores. I could only see the small core when it would pop in and out with the seeing. It was only visible as a quick flash when the seeing would settle. I am confident of my observation as I did see it multiple times in the right location. I think on a night of better seeing it would be a lot easier to see it. I will try it again on a better night.

[Uwe Glahn]

Gave it also a try and got it.

Conditions were good, transparency and seeing good but not excellent. As Jimi already mentioned the second core is difficult to spot. The star 0,5' SE has to be visible steadily with averted vision. With my 27-inch I got also several pops of a stellar source near the center. The closeness to the main core was not the problem. With 586x the distance seemed large enough. The difficulty was the faintness.

By the way, the galaxy neighbor group is a very nice view. I add a sketch when it is redrawn.