View Full Version : UGC 5189A and SN 2010jl 15.5 months later

2013-Jan-06, 10:22 PM
On November 3, 2010 SN 2010jl was seen in UGC 5189a. I imaged it on the 11th low in the east. Dawn came too fast and I missed getting any blue data but decided to process it anyway creating a pseudo blue out of the red and green data. I had no idea how well it worked.

On February 19, 2012 I decided shoot it again to get a better image of the galaxy. This one is a Jinx. Looking at the data when I processed it a few days ago I was shocked to see clouds had made a mess of it. Two of the luminance frames were nearly totally lost to clouds and the color frames were similarly hurt severely, especially the red which had nasty halos around brighter stars enlarging them greatly. I was about to can the whole thing when I noticed the supernova was still there even though 15 months had passed. The data is mostly weak which prevented me from getting much detail though seeing was excellent. The brighter parts of the galaxy where the SN are located were the only parts to come through with significant signal to allow me to eke out any more detail than my earlier shot. Color is likely even worse than the first try though all three channels used real data this time. I was pleased to see the blue came out rather similar for not even having any blue data to start with.

The supernova is a type IIn meaning it is a core collapse supernova and a super-luminous one being some 10 times brighter than most. There are several theories as to why this happens. One that seems to apply here is the shockwave hits and causes previously ejected gasses to glow brightly. At least that's what Chandra data indicates. What surprised me is the orange color of the object. It's not H alpha pink but red giant orange. I don't know if that is due to my red data through a thick haze or if it really is that color. Too late to go back and try again. I should have at least looked at the data but didn't think it a problem. Since it is back in the sky I looked at it last night (Jan 6, 2013 UT) though heavy gunk. Nothing has changed about the jinx! Seeing was poor but I saw no hint of the super nova so it has apparently faded away.

I've marked a Hubble Space Telescope image of the galaxy taken prior to the supernova with the location of it. It seems to have blown in a rather dark area. There's a rather blue star cloud just to its east. In fact in the first image the SN was also a bit orange but I marked the blue area as the SN in error assuming (I know -- never assume) blue is the expected color of a supernova. Not this one it appears.

Oddly, in my first image both the star cluster and the SN appear very bright. Why the cluster would be so bright I can't fathom. The result is a double object in the first image. This I don't understand at all. The double nature of the two is also seen in Adam Block's image at: http://www.caelumobservatory.com/gallery/UGC5189.shtml

UGC 5189 is a major train wreck of a galaxy in southwest Leo. Redshift puts it about 160 million light-years away. The upper part where SN 2010jl is located carries a separate designation of UGC 5189a. The UGC says of it: "Chaotic arc-shaped object, brightest in north-preceding part Probably chain of disrupted galaxies." The VV catalog confuses me with it's description: "Very faint spiral(?) with a stellar nucleus and a bright extended arm to the northwest." OK I agree the northwest part is by far brightest part. Is it calling the very blue star knot southeast of the "center" the stellar nucleus? A blue nucleus is extremely rare as they are normal made of old, red, population II stars. NED indicates the whole system might be classed as Im for an irregular of the Magellanic type. UGC 5189a as an Irregular system while the lower part is noted to be a Wolf Rayet galaxy, that is one in which Wolf Rayet stars dominate the spectrum. These are high mass stars near a violent death such as SN 2010jl experienced.

A slightly separated piece at the far southeast end carries a separate SDSS label and is listed as being a separate galaxy though it looks like it could be part of UGC 5189. To the southwest of UGC 5189 is a very distorted smudge of a blue galaxy also listed only the the Sloan Survey. It has virtually the same redshift as UGC 5189 and its parts. Has it interacted with UGC 5189? I have no idea. NED has little on it but for the redshift. Well above UGC 5189 is a super faint smudge hiding behind a 17th magnitude star. It is AGC 198337. For such a faint smudge it is surprisingly the closest galaxy in the entire image at a redshift distance of only 82 million light-years. It has no classification at NED but it must be a very low surface brightness galaxy.

The annotated image shows some other galaxies also likely members of UGC 5189's family as they share nearly the same redshift. Another group is seen at a bit over 800 million light-years.

There's one asteroid in the image to the northwest of UGC 5189 near the right edge. Note how broken the left (first) part of the trail is. That is due to those clouds I was complaining about. The first two frames were severely dimmed by them to the point the asteroid's trail disappeared a couple times.

14" LX200R @ f/10, L=4x10' RGB=2x10' (all with cloud damage), STL-11000XM, Paramount ME