J/A+A/497/619 New ultra-cool dwarfs from SDSS and 2MASS (Zhang+, 2009)
Ultra-cool dwarfs: new discoveries, proper motions, and improved spectral typing
from SDSS and 2MASS photometric colors.
Zhang Z.H., Pokorny R.S., Jones H.R.A., Pinfield D.J., Chen P.S., Han Z.,
Chen D., Galvez-Ortiz M.C., Burningham B.
<Astron. Astrophys. 497, 619 (2009)>
=2009A&A...497..619Z 2009A&A...497..619Z
ADC_Keywords: Infrared sources ; Stars, late-type ; Photometry, SDSS ;
Photometry, infrared
Keywords: stars: low-mass, brown dwarfs - stars: late-type
Abstract:
We try to identify ultra-cool dwarfs from the seventh Data Release of
the Sloan Digital Sky Survey (SDSS DR7) with SDSS i-z and r-z colors.
We also obtain proper motion data from SDSS, 2MASS, and UKIDSS and
improve spectral typing from SDSS and 2MASS photometric colors.
Description:
SDSS and 2MASS photometry of 129 ultra-cool dwarf candidates. The
photometric data are from the seventh Data Release of the SDSS
Photometric and the 2MASS All-Sky Catalog of Point Sources. Proper
motions are found by dividing the difference between the 2MASS and
SDSS coordinates by the observational epoch difference. Spectral types
are based on the relationship between spectral type and SDSS and 2MASS
colors.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table7.dat 124 129 SDSS and 2MASS photometry of 129 ultra-cool
dwarf candidates
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/282 : The SDSS Photometric Catalog, Release 6 (Adelman-McCarthy+, 2007)
http://www.sdss.org : SDSS Home Page
Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- SDSS SDSS Name (JHHMMSS.ss+DDMMSS.s)
22- 26 F5.2 mag rmag SDSS r band magnitude
29- 32 F4.2 mag e_rmag rms uncertainty on rmag
35- 39 F5.2 mag imag SDSS r band magnitude
42- 45 F4.2 mag e_imag rms uncertainty on imag
48- 52 F5.2 mag zmag SDSS r band magnitude
55- 58 F4.2 mag e_zmag rms uncertainty on zmag
61- 65 F5.2 mag Jmag 2MASS J band magnitude
68- 71 F4.2 mag e_Jmag rms uncertainty on Jmag
74- 78 F5.2 mag Hmag 2MASS H band magnitude
81- 84 F4.2 mag e_Hmag rms uncertainty on Hmag
87- 91 F5.2 mag Kmag 2MASS K band magnitude
94- 97 F4.2 mag e_Kmag rms uncertainty on Kmag
100-103 F4.2 arcsec/yr pm ? Proper motion
106-109 F4.2 arcsec/yr e_pm ? rms uncertainty of pm
112-114 I3 deg pmPA ? Proper motion angle
117-118 I2 deg e_pmPA ? rms uncertainty of pmPA
121-124 A4 --- Sp Spectral type by colors
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Acknowledgements:
Zenghua Zhang, zenghuazhang(at)hotmail.com
(End) Zenghua Zhang [Hertfordshire Univ., UK], P. Vannier [CDS] 11-Apr-2009