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NGC 7626 (17,774 of 18,816)

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NGC 7626

NGC 7626, LEDA 71140, MCG+01-59-057, UGC 12531, II 440, h 2233, GC 4940

RA: 23h 20m 42.68s
Dec: +08° 12′ 59″

Con: Pegasus
Ch: MSA:1256, U2:214, SA:17

Ref: SIMBAD

(reference key)

Type: galaxy (radio), E...

Mag: B=12.8, V=?

Size: 2.754′ x 2.344′
PA: 10°

Historical observations

William Herschel (c.1784)

Synonyms: H II-440

Discovered in 1785 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "pB, pS, bM."

Published comments

Sulentic & Tifft (1973)

The RNGC (Sulentic and Tifft 1973) notes that this is a 13.0 mag galaxy. Their coded description reads BE,R,BM.

[amastro] DSS flaw near NGC 7626

For those of you who have recently spent so much enjoyable time viewing this cluster, I would like to see if anyone noticed the missing star (from Palomar's The Real Sky) close to NGC7626. Like most of you, the field stars are signposts for me. 7626 usually gets a comment about a 14m star less than one minute to the west (Skiff - Sanner, etc.) However, I was using a negative print from The Real Sky and had affixed in my mind a second 14m star to the E about 3m distance. In the 36", I was gleefully enjoying all the faint smudges, when I realized that the bright galaxy I was observing, didn't have the second 14m star to the E. After convincing myself that I was, indeed, viewing 7626 due to the correct locations of about 20 other galaxies, I returned to 7626 and reconfirmed that the star on the Palomar survey just wasn't there visually.

Smudge on the plate? Sure looks stellar! Variable star? Visible due to red plates? I cannot find this 14m star on any other plate. RA 23h 20m 50.5s and Dec 08d 12m 40s N. Don't let me fret about this missing star too long. It drives me crazy! Anyone know what happened? Neal

------------------------------------------------------------------------

Neal's "non-star" appears to be a flaw appearing only on the POSS-I E plate. Yep, looks pretty good on the SkyView DSS image. But it does not appear in the USNO-A2.0 star catalogue---and an isolated star this bright should (not mag. 14, but more like 16th). The killer however is grabbing a POSS-II scan from the Web, which shows no star at this place. If it were a supernova appearing at the time the POSS-I plates were taken (the POSS-I plate-pairs were taken back-to-back on the same night, unlike the POSS-II and southern surveys, which are not ever taken this way), then it would show up in USNO-A2.0 almost without fail. I'm out at the LONEOS telescope now, so can't look at the actual POSS-I/II prints/films, but I'm willing to bet that this is a very convincing flaw. Since the POSS-I red plate (same as the RealSky image) is something like a 50-minute exposure, any asteroid would have trailed noticeably, so that's not what this is either. If I have the energy tomorrow, I'll look at the prints and confirm that it doesn't appear on the blue image. This is probably worth reporting to the NED folks, since their on-line of the galaxy will contain the flaw as well.

\Brian

------------------------------------------------------------------------

I spent about a half-hour with observing partner Ted Forte enjoying counting upwards to 20 faint galaxies in the Pegasus 1 area with my 25" last Thursday evening after reading Dave Knisley's notice on amastro. I'd say the naked-eye magnitude limit was about 6.1 that night. I must admit I was so excited by the number of galaxies I didn't notice the absence of the star in question. With a field so sprinkled with galaxies I was "galaxy hopping" more than "star hopping".

Now I can't wait to get back to the area; this time to NOT see a star that is shown on Real Sky. Neal has proven himself a very keen observer; believing his own observations and questioning the Palomar Sky Survey. Apparently he's correct, and the error lies on the POSS. I for one can't wait to hear from Brian Skiff after looking at one of the original plates. I once had the good fortune of seeing some of these beautiful original plates once. They'd be great to have, but would never fit in my car when going observing! Let us know, Brian.

Thanks.

Kent Blackwell

------------------------------------------------------------------------

Hi, Brian,

I've seen other things like this on the DSS. Sometimes they show up on the prints, sometimes not. This particular one is irregularly fuzzy, at least in the SkyView image I'm looking at now. If it were real, I would have guessed a peculiar compact companion to N7626.

This is a good demonstration as to why multiple-epoch (at least; multiple observatory is even better!) surveys are valuable. SkyView now has NEAT/SkyMorph available for part of the sky, though unfortunately, not this part. Onwards through the fog ... Harold

--------------------------------------------------------------------------------

Harold,

Arizona amateur Neal Galt has noticed a non-star on the POSS-I red plate DSS scan near the galaxy NGC 7626. This is the eastern of the co-dominant pair in the Pegasus I cluster. Since the object does not show up on the POSS-II scan or in USNO-A2.0, I thought at first this was a flaw on the red plate. However, checking our POSS-I prints and POSS-II films just now, it appears on _none_ of them, and so is evidently a flaw (piece of dirt) present when the plate was scanned. The image structure is very close to that of a star, as can be seen in the NED image of the galaxy. It is the fairly bright (mag. 15-16) object about halfway from the center of the galaxy to the left edge of the NED frame. Notice a few other elongated bits of dust in the image, also not present on our POSS-I prints. I'm not sure this rates comment in the NED notes collection, but somebody's bound to notice it again.

I append below Neal's message to the 'amastro' mailing-list, which connects many of the active visual deep-sky observers worldwide. His position for the flaw seems to be accurate within a couple arcsec.

\Brian

=====================================

Date: Mon, 11 Oct 1999 16:50:39 -0700

From: Neal Galt(neal@primenet.com)

To: "amastro@egroups.com"

I finally got a clear night last night, and immediately returned to the wonderful Pegasus 1 cluster of galaxies. Neal Galt is entirely correct, the 14th magnitude star east of galaxy N7626 does not exist.

There are a few galaxies I need help with magnitudes, or at least suggestions of whether I have a chance of seeing them. I've bagged a total of 21 galaxies in this cluster, using MegaStar charts and DSS printouts, but have not been able to see the ones listed below. My sky last night was about 5.7 naked-eye, though it's usually about 6.2.

I only have the MAC numbers, as all of these are from MegaStar listings.

MAC 2319+0816A, 23h 19m 26.9s, +08 16' 25"

MAC 2319+0816B, 23h 19m 49.3s, +08 16' 01"

MAC 2319+0805, 23h 19m 37.5s, +08 05' 12"

MAC 2321+0804, 23h 21m 5.1, +08 04 44

I spent over two hours last night in search of these with my 25" f/5, to no avail!

Kent Blackwell, Virginia Beach, VA

------------------------------------------------------------------------

From NED:

MAC 2319+0816A no object in NED at this position

MAC 2319+0816B = [OBC97] P01-5, given with mb=17.5

MAC 2319+0805 no object in NED at this location

MAC 2321+0804 no object in NED at this location

As another tack, you might try looking up the objects in USNO-A2.0 and the GSC using VizieR. If they're small, the blue magnitudes (not the red) are often in the right ballpark.

\Brian

------------------------------------------------------------------------

Brian......Thank you so much for confirming that, ONCE AGAIN, I have discovered irrelavent impedimenta. The least we could have done, was name it NDF 1 (Neal's dust flake #1). :~)

I did enjoy the "hunt", however, and I'm sure the group appreciated how rapidly you were able to solve the mystery. Regardless of the outcome in this case, it is obvious that any serious members in this group can count on expert assistance with observational discoveries or oddities. Thank you for the personal time expended. Neal

------------------------------------------------------------------------

Modern observations

(unknown)

In this field sprinkled with stars are two bright, round galaxies, NGC 7619 and 7626. Clearly seen with a 6-inch, they are about 7' apart. The easternmost galaxy, NGC 7626, is about 1' across and rises much to the centre to a tiny starlike nucleus. The galaxy pair make a large cross with two 8th mag stars lying north and south.

Gramer, Lew (IAAC)

IAAC Observer: Lew Gramer, Site classification: rural; Limiting magnitude: 6.9 (zenith); Seeing: 6 of 10 - above average; 20" f/5 Tectron truss-tube dob Newtonian reflector: "Member of the Pegasus I group. Forming the left "eye" of a nice pair with n7619 (above), this galaxy was remarkably similar to its companion at first glance in 70x. But with the use of a friend's 16mm Nagler (160x), suddenly the two "twins" began to diverge from one another. First n7626 was slightly fainter than its neighbor. Second, it showed no brightness "steps" like -19, brightening gradually to a diffuse core without a nucleus. Finally even at 420x, 7626 appeared quite round, with the notable exception of a "notch" or flattened area to the W, perhaps due somehow to interaction with -19. I'd love to be able to apply yet MORE power to this curious object - again, with better seeing!"

Steve Gottlieb

Steve Gottlieb notes: "17.5-inch: bright, slightly elongated 4:3, brighter core (although less intense than N7619), substellar nucleus. This is the second brightest in the Pegasus I cluster and appears similar to N7619 6.9' W. 8-inch: faint, small, bright core. A mag 6.5 star is at the S edge of the 40' field.

Brian Skiff

POSS: m14-15 * 54" W/sl N. gx nrly circ, sl elong NNE-SSW (smaller pa than -19). 6'.85 E of -19.

7Sam: * V=14.42/0.81 (ApJS 64,601).

15cm - approx same overall mag as -19, but poss sl lgr and w/circ sub*ar nuc--- def no *-like center @ 140x. poss oval elong SSE-NNW; m15 * defines W border, lies WWNW of nuc. strong even concen but no well-def core. BS, 29Sep1989, Anderson Mesa.

20cm - seems brtr than -19. *ar nuc w/much more diffuse core and halo 1'x1'.

25cm - pair w/-19. not as concen as -19, a bit smlr w/broader core 1' diam.

30cm - lgr than -19, a little fntr. lower sfcbr. 30" core, 1'.2 overall. sev *s nrby, esp 1' W. non*ar nuc. sl elong pa135.

- forms nrly equilat triangle w/m10 * N and -19. vsim to -19. circ, 1'.0 diam. evenly concen to f *ar nuc that is not as consp as that in -19. 50" W is m14 *. 5Sep1983, USNO.

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