by Steve Gottlieb
waste-of-time was NGC 1240. What gives? Single star? Whoopy. Am I missing something?
Nope. It's probably a double star, mistaken as nebulous by William Herschel. This is Harold Corwin's write-up from the NGC/IC Project site (did you see the article in S&T?).
NGC 1240 is probably the double star 34 sec east and 3.7 arcmin south of WH's position. His description, from one observation on 12 Sept 1784 ("Suspected, 240 left a doubt; eF and vS, most probably 2 close stars; between 2 stars," quoted by Dreyer in the 1912 Papers collection) fits perfectly, and there is nothing else in the area that matches. The position difference is not unexpectedly large for WH's early observations.
Coincidentally, I also looked at a couple of NGC double stars on Saturday night and had Randy verify one of these observations! Pretty boring stuff, but it's curious to see why the original observer thought it might be a fuzzy something-or-another.
| N7143 | 21 48 53.9 +29 57 24 |
|---|---|
18" (10/25/03): this is a faint, very close pair of mag 15 stars which are just resolved at 257x. At first glance at 215x, this pair appeared nebulous. Also, an easier distinctive pair of mag 14 stars is just 2' E. Located 28' SW of mag 5.1 14 Pegasi. | |
| N7161 | 21 56 57.2 +02 55 39 |
18" (10/25/03): this is a close pair of faint mag 15 stars at 9" separation, situated nearly at the midpoint of two mag 13 stars ~2' N and 2' S. Resolved at 250x, but the faint pair appears nebulous at lower powers. Located 10' N of a distinctive equilateral triangle of stars highlighted by mag 8.9 SAO 127184. | |