2005A&A...436..853L -
Astronomy and Astrophysics, volume 436, 853-865 (2005/6-4)
A near-infrared survey for new low-mass members in α Per.
LODIEU N., McCAUGHREAN M.J., BARRADO Y NAVASCUES D., BOUVIER J. and STAUFFER J.R.
Abstract (from CDS):
We present a near-infrared (K'-band) survey of 0.7 square degree area in the α Persei open cluster (age=90Myr, distance=182pc) carried out with the Omega-Prime camera on the Calar Alto 3.5-m telescope. Combining optical data (R
c and I
c) obtained with the KPNO/MOSA detector and presented in Stauffer et al. (
1999ApJ...527..219S) with the K' observations, a sample of new candidate members has been extracted from the optical-infrared colour-magnitude diagram. The location of these candidates in the colour-colour diagram suggests that two-thirds of them are actually reddened background giants. About 20 new candidate members with masses between 0.3 and 0.04M
☉ are added to the ∼400 known α Per cluster members. If they are indeed α Per members, four of the new candidates would be brown dwarfs. We discuss the advantages and drawbacks of the near-infrared survey as compared to the optical selection method. We also describe the outcome of optical spectroscopy obtained with the Twin spectrograph on the Calar Alto 3.5-m telescope for about 30 candidates, including selected members from the optical sample presented in Barrado y Navascues et al. (
2002A&A...395..813B) and from our joint optical/infrared catalogue. These results argue in favour of the optical selection method for this particular cluster.
Abstract Copyright:
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Journal keyword(s):
stars: low-mass, brown dwarfs - techniques: photometric - techniques: spectroscopic - infrared: stars - stars: Hertzsprung-Russell (HR) and C-M diagrams - Galaxy: open clusters and associations: individual: α Persei
VizieR on-line data:
<Available at CDS (J/A+A/436/853): table2.dat>
Nomenclature:
Table 2: Cl* Melotte 20 LMB NNNNN (Nos 1-22129).
CDS comments:
in the ref list GIZIS 1999AJ.118.997G instead of 1999AJ.117.508G
Simbad objects:
22170
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