Object of the Week October 25, 2015 NGC 100 "A Ghostly Streak"

[Jimi Lowrey]

NGC 100

Pisces

RA
00 24 02
DEC
+16 29 08

Type Superthin

Mag 13.3

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NGC 100 was found by the famous comet hunter Lewis Swift on the night of Nov 10, 1885 with his 16" Clark refractor. He recorded it "Very faint, pretty small and much extended" I think he understated the "much extended" part! This for me is my most favorite of all the edge on galaxies that I have viewed to date. For many years I poured over the Flat Galaxy Catalog looking at many of this type of galaxy but NGC 100 is my favorite so far. I return to it every fall and it has become like an old friend to me. I remember the first time I swept up this ghostly streak like it was last night. I was in Tates Hell swamp in the Florida panhandle about 15 years ago and still can visualize the low surface brightness streak coming in to view of the 31 Nagler.

1832

There is more to NGC 100 than its LSB streak. There is also a challenge object that most know little about. Its the galaxy PGC 1509358 which lies near the South West end of NGC 100. I used the SDSS photomertry to get an approximate V Mag of this little guy and I came up with 17.2 V mag +/-. This should make it detectable with many of the scopes on this forum. So give it a go, you might be one of the first to visually observe this galaxy!

1833

I hope you will view NGC 100 next time you are out under the stars. I can never get enough of its ghostly streak and hope it too will become one of your fall favorites. Please let us know of your observations of the PGC 1509358 and like I said, you might be one of the first to view this galaxy.

"Give it a go and let us know!
Good luck and great viewing!"

[vesna71]

I observed this galaxy with my 14 " on 27 September 2014 ( SQM 21.13 ), I could guess at low magnification, it is rather difficult even to 13 mm, is a blade of light very weak elongated from north-east to south-west, I can not perceive details, it is visible even with the 8 mm which increases the faint stars of the field but otherwise nothing to write down.
Unfortunately I did not see the companion galaxy.
Ciao.

[Howard B]

Nice object Jimi!

Here's my observation of NGC 100 from a few years ago with my 28 inch:

"A subtle beauty! Very nice edge-on galaxy that takes magnification well even though it has a low surface brightness. Only a slight central brightening, and the ends of the galaxy gradually taper into the darkness. 408x, 21.61
SQM."

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I wasn't aware of PGC 1509358 either Massimo, so it's an excellent reason to go back for another look.

[Jimi Lowrey]

Great looking drawing Howard.

I am surprised that you did not see the PGC galaxy? You got the stars that frame it in your drawing. Now that you know were to look should make it easier to catch.

[Howard B]

Thanks Jimi, and I'm sure I would have seen it had I looked for it with higher power, and that's what I'll try next time.

[Uwe Glahn]

Nice reminder Jimi. I have a quick and dirty observation of NGC 100 with the 27" and like Howard without the PGC companion. Around 18bmag sounds and looks plausible at the DSS. But it could be hard and at the limit for the 28" class. I will revisit and try the pair again.

With the 16" the galaxy was not so fascinating like it seems to be. The superthin character was visible very good but the faint surface brightness made it more difficult than the famous number fools.

[Uwe Glahn]

Got it, but a tough observation for real.
With 27" and bad seeing the galaxy pops in and out of view several times. The faint star 0.5' SW (which was sketched from Howard also) was a little bit easier to catch. I also tried the faint companion 4' NW. It was also visible, equal difficulty like the near PGC companion. Sketch will be given later.

[Jimi Lowrey]

Nice observation Uwe. Congratulations on catching the PGC.

[wvreeven]

Fantastic object, Jimi, but ouch a tough one. I went out tonight with my 20" and gave it a try. Under slightly hazy SQM 20.8 skies I saw a superthin streak of light at 150x and 320x. At 545x the galaxy nearly became invisible though an elongated part lit up in the center. Very nice! No sign of the companion, unfortunately.

Clear skies!

[wvreeven]

I had another try tonight. The conditions were a little better than last night. Less humid. At 545x I could see the three faint stars next to NGC 101 which can be seen below it in the picture. Two of the three point towards the companion galaxy. I had a long, hard look and I may have seen it but I am not 100% sure. I had to stand in an awkward position between two steps on my ladder, one being too low and the other too high. O well, I guess this galaxy is beyond the reach of my telescope.


Clear skies, Wouter

[Steve Gottlieb]

Jimi Lowrey, Mark Wagner and I had a look at NGC 100 last night in the 48-inch. Of course the superthin is the main treat, but we also looked at the companion (listed in NED as 2MASX J00235704+1627450 and in HyperLeda as PGC 1509358). Conditions were not the best, with very high relative humidity (the observatory floor was getting sopping wet). Nevertheless, the companion was not a difficult object at 488x (visible continuously to me with averted vision, though quite small (perhaps 10"). Besides the four mag 15-16 stars just south of the galaxy, a mag 17 star is just 30" SW of PGC 1509358.

LEDA gives a blue magnitude of 17.9 for the companion. That seems reasonable. The derived V magnitude is 17.2 using the g and r magnitudes in SDSS. SDSS also gives a redshift of .099. Plugging that in to Ned Wright's Cosmology Calculator gives a light-travel time of 1.3 billion years!