NGC/IC Project Restoration Effort
(This is a very very beta version)
NGC1252
Basic Information
Location and Magnitude
Right Ascension: 3:10:44.0
Declination: -57:45:30
Constellation: HOR
Visual Magnitude:
Historic Information
Discoverer: Herschel J.
Year of discovery: 1834
Discovery aperture: 18.3
Observational
Summary description: Cl of 18 or 20 st
Sub-type: *Grp
Corwin's Notes
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NGC 1252 is a sparce cluster (actually, a "cluster remnant"; more below) 20
arcminutes north of the GC and NGC position. JH's CGH position for HD 20037
-- which he adopted for the cluster -- is nearly perfect, so I suspect a
transcription error during preparation of the GC. His description, "Star 8m,
the chief of a cluster of 18 or 20 stars" also fits perfectly, so there is no
doubt about the identity of the cluster.
The position I've adopted is a few arcmin northeast of the bright star, more
or less in the middle of the the group of stars that JH describes. Brian
Skiff moves on another 10 or so arcmin to the northeast, apparently to include
another clump of stars beyond the boundaries of what I believe is JH's
cluster.
RNGC, Wolfgang Steinicke, and Tom DeMary give the nominal NGC position, where
only two 13th magnitude stars are found.
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Brent Archinal in "Star Clusters" has a note telling us that Eggen (PASP 96,
70, 1984) did not regard this as a physical cluster, just a random clump on
the sky. Brent goes on to point out, however, that the 20 arcminute offset
in the positions may mean that Eggen actually measured field stars at the
wrong position rather than cluster members at the correct position. A major
part of Eggen's work was pointed at finding the distance to TW Horologii, so
he does not seem to have been overly concerned with the cluster itself.
However, a more recent paper by de la Fuente Marcos, et al. (MNRAS 434, 194,
2013) directs its attention directly to the question of whether this is a
cluster or not. The authors find that there is indeed an old, metal-poor
cluster remnant here; furthermore, at a distance of nearly 900 parsecs from
the Galactic disk, it is one of the furthest (from the disk) cluster remnants
known. Checking their table, I find that all of the stars they studied are
within twenty arcminutes of JH's CGH position, but only 50 are within twenty
arcminutes of the GC/NGC position, so they did indeed get the right object.
So, a questionable cluster from JH's sweeps has turned out to be a most
interesting object!
Steve's Notes
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NGC 1252
14" (4/7/16 - Coonabarabran, 142x): fairly large scattered group of ~20 stars in a 10' region. Includes mag 6.6 HD 20037 on the southwest end and mag 8.7 HD 20059 on the north side. Not impressive but detached in the field.