View Single Post
  #18  
Old 17-11-2010, 07:25 AM
glenc's Avatar
glenc (Glen)
star-hopper

glenc is offline
 
Join Date: Jun 2005
Location: Terranora
Posts: 4,406
globular ngc 1261

NGC 1261, Dun 337, JH 2517
GC in Hor, mag 8.3, size 6.9’, RA 3.204, dec -55.20
Distance 53,500 light years

This GC seems brighter than mag 8.3 to me (GC)
NGC 1261 is 13 deg east of Achernar, see maps a and c in post 15.
Other GC at this time of the year are: NGCs 104, 288, 362, 1851, 2298

Descriptions
On 28/9/1826 Dunlop discovered NGCs 1261 (at ~2:40am), 1433, 1527 and 1553 (at ~3:45am)
Moonrise (18%) was 3:00 am and astro-twilight 4:15 am. (not DST)
(Parramatta house was at latitude 33.82S and longitude 151.00E)
Dunlop 337 “A very bright round nebula, about 1.5’ diameter, pretty well defined and gradually bright to the centre. A small star north following.” [star mag 9.1]
http://picasaweb.google.com/dunlop18...28570659595186

John Herschel (JH) 2517: 5/12/1834 "bright; large; irregularly round; 2.5' diameter; all resolved into equal stars 14 mag.
Has a star 9th mag 45 N.f. 3' distant." [m9.1, pa 54, 3.6’]
His second observation recorded it as "pretty bright; round; very gradually brighter in the middle; 3' across; resolved into stars of 15th magnitude. A very faint nebula (??) precedes." [there is no nebulae preceeding, GC]

Hartung notes: “This well condensed globular cluster lies in a fine field; 30cm resolves it into crowded stars right to the centre. It is about 2.5’ across and the scattered outliers do not extend far; the stars are however very faint and hard to detect with 20cm although the cluster looks granular. It is a fine bright object, conspicuous with 10.5cm.”
See Auke Slotegraaf http://www.fortunecity.com/roswell/borley/49/u419.htm#NGC1261

IIS image by Scott tornado33 (2007)
http://www.iceinspace.com.au/forum/s...highlight=1261
http://www.iceinspace.com.au/forum/a...1&d=1192831138
The bump of stars on the left, NW side is visible in a 12”. (GC)

Image from Chile by Daniel Verschatse
http://www.astrosurf.com/antilhue/ngc1261.htm

Last edited by glenc; 17-11-2010 at 08:30 AM.
Reply With Quote