Observing Report: Mostly Vela, Carina, Puppis and Centaurus

[Akarsh Simha]

I had the opportunity to spend three nights under variable-quality Bortle 4 skies in Coorg, southern India as part of a star party organized by the Bangalore Astronomical Society. I was enjoying and providing feedback on my new 12" f/4 ultra-portable travel scope designed and constructed by a friend here in Bangalore. He intends to premier his product at NEAF 2025. My fellow observer Gautham Ramachandra and I were sharing the telescope. My program consisted of southern targets picked out of the pages of Interstellarum Deep-Sky Atlas, whereas Gautham had put together a list pulling targets from various sources perhaps including ADS.

Overall, we observed about four dozen objects, and I'm highlighting a few of them here.

NGC 2480 and NGC 2481: A pair of galaxies in Gemini put on the list by Gautham. At 203x, NGC 2481 appeared bright, somewhat elongated, continuously visible to direct vision. NGC 2480 appeared very very dim, I got only 3--4 flashes. This is a pair I'd like to see with my 28" when I'm back in California. Looking at the Legacy Survey image, my best guess is that NGC 2481 might be foreground although NGC 2480 shows signs of being a merger on its own. There is some light connecting the two galaxies but I can hardly see any severe distortion in NGC 2481. If anyone knows more about this pair, I'm all ears.

LGG 158: Fellow deep-sky observer Sudhash Natarajan was working through a bunch of galaxies in Cancer in his 12" that we later found were members of this group, through Owen Brazell's article. We picked up NGC 2563, NGC 2562, NGC 2560 and NGC 2569 in his scope. Under the conditions, NGC 2569 was visual torture, flashing into my averted vision only about 3–4 times with location later verified against DSS. Also fascinating is an asterism that Sudhash stumbled upon while finding this object -- a chain of stars reminiscent of the integral sign galaxy or of Hickson 55 at 08:23:26 +21:51:23. If I could name it I'd call it Natarajan's Integral Sign.

NGC 2626: A cool reflection nebula in Vela appeared as a distinct haze around a moderately bright star. Another star of similar brightness had no such haze. The haze was asymmetric, appearing thicker on the southeast of the star.

NGC 2792, a planetary nebula in Vela, appeared bright and round with a 3.5mm Pentax XW producing 350x. Central star quite strongly suspected. Could not determine anything else. Weak suspicion of brightenings at N and S ends.

NGC 3201, a fine globular in Vela at 175x sported resolved stars scattered even in the core region, but averted vision revealed a grainy background of faint stars. There wasn't a strong density increase towards the center of the cluster.

NGC 3132, the Eight Burst Nebula, was incredible! A very bright central star sported a bright halo elongated NW-SE roughly in a 3:2 ratio. Hugging the central star on the leading side was a V-shaped dark rift! Fascinating!

NGC 3347, 3358 and 3354: A nice line-up of galaxies in Antlia, appeared as collinear glows in the FOV of a 10mm Delos. 3347 was the brightest, visible continuously to direct vision, with a brighter middle and a N-S elongated halo. 3354 was a roundish, faint glow whose core was visible almost continuously to direct vision. The halo could be held continuously in averted vision. This was the dimmest of the three. NGC 3358 was the second brightest, visible continuously to direct vision. Only the core was definitively detected.

NGC 5286 is a very nice globular cluster near a bright naked eye star in Centaurus. The round, dense GC sported a much brighter and denser central region. The outer regions were resolved. A star stood out on the ENE of the core at about 80% the radius from the center.

NGC 5307 is a funky-looking (in photos) planetary nebula in Centaurus. It appeared as a rectangular glow elongated roughly north-south. I estimated its size as about 16 arcseconds.

IC 4406 or the Chain-Link Nebula, a fascinating planetary nebula in Lupus, appeared as a bright round blob embedded in a rather dim and subtle east-west elongated halo visible with averted vision. The halo appeared brighter on the western side than on the eastern side of the center.

Henize 2-7 at 200x was unfortunately observed through haze. I confirmed the nebula by seeing a strong response to a UHC filter, using a nearby star (UCAC4 207-019058) for comparison. No detail could be discerned. The nebula lies in a fascinating, long line of dim stars. This line of dim stars was visible with averted vision like a dividing line running through the eyepiece. If it is as yet unnamed, perhaps I would suggest calling it the Great Wall of Vela?

NGC 986 is a nice barred spiral in Fornax. At 122x, the galaxy appeared considerably bright. I picked up the elongated bar but struggled to fix its exact orientation beyond roughly NE-SW. The spiral arm bending on the NE side from the bar appeared more prominent than the SW side. The SW spiral arm emerging from the bar must be considered a weak observation.

NGC 1128 is the "double star galaxy" at the center of Abell 400 in Cetus discussed in Scott's thread on the subject. Gautham put it on the list. It rendered many intermittent strong flashes to averted vision at 175x after knowing the exact position. Bumping the power to 270x, I got 3–4 flashes of resolution of the pair. We were observing it at less than ideal airmass and through some haze.

NGC 2440, a planetary nebula in Puppis, may be the most fascinating observation of this run. Observed patiently at 350x, the core appeared complex with 2–3 bright points including a stellar condensation. With averted vision, the halo appeared bipolar elongated northeast-southwest. The core detail was difficult to determine and I suspected two parallel brightenings on the NW and SE ends of the core. These brightenings appeared elongated slightly NE-SW, i.e. along the major axis of the outer halo. This gave the core region a dumbbell-shaped appearance, the dumbbell extending NW-SE. Observing further, I picked up on a stellar point, perhaps a superposed star, NNE of the center in the core region, in addition to a central star. I cannot corroborate these stellar condensations with images on the internet. I was disappointed that the orientation seen on the DSS2 Color image on my red-filtered laptop disagreed with the orientation of the halo I had observed, but I was overjoyed when I got home and looked at high-resolution images of the nebula, only to find the orientation matching!

NGC 2452, a planetary nebula in Puppis, was observed under very hazy conditions. Yet at 350x, I detected two confounding elongations: E-W and N-S. The north-south elongation was more prominent. I was unable to catch any other detail, other than perhaps suspecting that the northern rim was slightly brighter. This nebula looks fascinating in images and I must definitely visit it in my 28".

Not really deep-sky, but Mars, at 350x, appeared mushy under the poor transparency. I could nevertheless see a polar ice cap on one end and a dark surface feature on the other end.

Clear Skies

Akarsh

[Scott Harrington]

Thanks for your report on NGC 2440 and NGC 3132. I've now moved them near the top of my list to view with my 16-inch. And even though I've seen NGC 5286 in my 130mm at a max altitude of 2.7*, I've yet to glimpse NGC 5307. Your report certainly makes me want to see it! As for Henize 2-7, several years ago my friend Lauren Herrington saw the star chain you mentioned from her previous home in Houston and thought it looked like a harpoon. She showed it to Amelia Goldberg or someone like that who then nicknamed it "Herrington's Harpoon." This was back in 2018 or so.

I wonder how bright you would rate the skies there.

Scott H.

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[Akarsh Simha]

Thanks for the inputs Scott!  I figured that the chain would have been discovered several times earlier. In fact, Gottlieb mentions it in this 2008 observing report:

https://groups.io/g/amastro/topic/planetaries_from_australia/51295124

My skies weren’t very dark, maybe a good Bortle 4 at best, lots of haze and moisture. I think the moisture is inescapable in south India.

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