NEW CLUSTER IN PUPPIS
-------------------
John Pazmino
NYSkies Astronomy Inc
www.nyskies.org
nyskies@nyskies.org
1994 March 1
The delegation of [Amateur Astronomers] Association members at the
Florida Winter} Star Party discovered an new undocumented star
cluster in Puppis. Lee Baltin, Arline Caldwell, and John Pazmino made
the find during starbrowsing at the starparty site on West Summerland
Key, Florida, at about 10:30PM on Saturday 12 February 1994.
The new cluster was spotted first by Caldwell, in her 10x80
binoculars, who called the others to confirm it. The group then
examined it in Baltin's 125mm Newton telescope and photographed it
with Pazmino's camera. Being on none of the charts on hand, even those
of nearby telescopists on the field, its position and description were
duly noted for checking back home in the City. Caldwell's Cluster -
after the AAA member who initially came onto it -- is at RA 08h 02m,
dec -50d 36m (2000), in the southeast corner of Puppis.
Caldwell's Cluster lives in a very rich Milky Way field visited
for centuries by binoculars, telescope, and eye alone. It sits 3-1/2
degrees southsouthwest of Regor, or gamma Velorum, itself a bright
wide binary, and two degrees southwest of the bright cluster NGC2547.
Just northwest of Caldwell's Cluster is the bright wide binary
Dunlop 59 and the bright semiregular variable V Puppis.
It is of overall the 7th magnitude and about 30 minutes in
diameter. It consists of a single star of 7th magnitude, SAO235688,
surrounded by tens of scattered stars of 8th to 10th magnitude. In the
binoculars the cluster appears as a soft patch around this star, but
even a low-power telescope breaks it into separate stars. There is no
condensation, the star density being even thruout the mass.
Caldwell's Cluster shows plainly on Vehrenberg's Photographic
Star-Atlas (plate 372) and the Japanese Book of Constellations (page
111), and on just about any photograph of the area that shows the
Milky Way distinctly.
It is absent from the usual and common references for deepsky
objects and from rather uncommon ones, too. These include Burnham's
Celestial Handbook, Dunlop's Catalogue of [Southern] Nebulae and
Clusters of Stars, Godillon's Atlas du Ciel, Lynga's Catalogue of Open
Cluster Data (ADC-CD edition), Ruprecht's Atlas of Open Star Clusters,
Sagot & Texeraeu's Revue des Constellations, Luginbuhl & Skiff's
Observing Handbook, Tirion's Sky Atlas 2000. In sum, Caldwell's
Cluster is wanting from cartographic charts and tabulated catalogs.
Both The_Sky and Earth Centered Universe fail to mark Caldwell's
Cluster by a symbol. However they both do plot enough dim stars at its
site to match the cluster's overall aspect in the sky.
Caldwell's Cluster misses the horizon of New York by its far
southern declination; in fact, Regor clears the southern horizon by
but two degrees. Its location among the stars of Puppis and Vela is
marked on the accompanying map HERE drawn by Earth Centered Universe for
the moment of discovery.