J/AJ/126/2449 Nearby ultracool dwarfs in galactic plane (Reid+, 2003)
Meeting the cool neighbors.
VI. A search for nearby ultracool dwarfs in the galactic plane.
Reid I.N.
<Astron. J., 126, 2449-2461 (2003)>
=2003AJ....126.2449R 2003AJ....126.2449R
ADC_Keywords: Stars, dwarfs ; Stars, late-type ; Photometry, infrared ;
Stars, nearby
Keywords: Galaxy: stellar content - stars: low-mass, brown dwarfs -
stars: luminosity function, mass function
Abstract:
Surveys for nearby low-luminosity dwarfs tend to avoid the crowded
regions of the Galactic plane. We have devised near-infrared
color-magnitude and color-color selection criteria designed to
identify late-type M and early-type L dwarfs within 12pc of the Sun.
We use those criteria to search for candidates within the regions of
the Galactic plane (|b|<10°) covered by the Second Incremental
Data Release from the Two Micron All Sky Survey (II/241). Detailed
inspection of the available photographic images of the resulting 1299
candidates confirms only two as ultracool dwarfs. Both are known
proper-motion stars, identified in the recent survey by Lepine et al.
(2003, Cat. J/AJ/125/1598). Despite the low numbers, the inferred
surface density is consistent with comparable surveys at higher
latitudes. We discuss the implications for the luminosity function and
consider means of improving the efficiency and scope of photometric
surveys in the plane.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 91 101 Ultracool dwarf candidates with |b|<10°
table2.dat 99 31 Ultracool candidates from Luyten's surveys
table3.dat 94 61 2MASS data for LSR proper motion stars
--------------------------------------------------------------------------------
See also:
II/241 : 2MASS Catalog Intermediate Data Release (IPAC/UMass, 2000)
I/98 : NLTT Catalogue (Luyten, 1979)
J/AJ/123/2806 : Nearby stars in the NLTT catalogue (Reid+, 2002)
J/AJ/123/2822 : Photometry of southern NLTT stars (Reid+, 2002)
J/AJ/123/2828 : Spectroscopy of northern NLTT stars (Cruz+, 2002)
J/AJ/126/2421 : 2MASS-Selected sample of ultracool dwarfs (Cruz+, 2003)
J/AJ/126/3007 : Spectroscopy of faint red NLTT dwarfs (Reid+, 2003)
J/AJ/128/463 : A preliminary 20pc census from the NLTT cat. (Reid+, 2004)
J/AJ/130/1680 : LSPM-North proper-motion catalog nearby stars (Lepine+, 2005)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh Hour of Right Ascension (J2000)
4- 5 I2 min RAm Minute of Right Ascension (J2000)
7- 11 F5.2 s RAs Second of Right Ascension (J2000)
13 A1 --- DE- Sign of the Declination (J2000)
14- 15 I2 deg DEd Degree of Declination (J2000)
17- 18 I2 arcmin DEm Arcminute of Declination (J2000)
20- 23 F4.1 arcsec DEs Arcsecond of Declination (J2000)
25- 30 F6.3 mag Jmag The 2MASS J band magnitude
32- 36 F5.3 mag e_Jmag Error in Jmag
38- 43 F6.3 mag Hmag The 2MASS H band magnitude
45- 49 F5.3 mag e_Hmag Error in Hmag
51- 56 F6.3 mag Ksmag The 2MASS Ks band magnitude
58- 62 F5.3 mag e_Ksmag Error in Kmag
64- 90 A27 --- Comm Additional comments
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- NLTT NLTT (Cat. I/98) number
7- 17 A11 --- Name Other name
19- 20 I2 h RAh Right ascension (J2000.0)
22- 23 I2 min RAm Right ascension (J2000.0)
25- 28 F4.1 s RAs Right ascension (J2000.0)
30 A1 --- DE- Declination sign (J2000.0)
31- 32 I2 deg DEd Declination (J2000.0)
34- 35 I2 arcmin DEm Declination (J2000.0)
37- 38 I2 arcsec DEs Declination (J2000.0)
40- 42 I3 deg GLAT Galactic latitude
44- 47 F4.1 mag rmag ? Red magnitude from NLTT (I/98) or
LHS (I/87)
49- 53 F5.2 mag Jmag 2MASS J magnitude
55- 58 F4.2 mag J-H 2MASS J-H colour index
60- 63 F4.2 mag H-Ks 2MASS H-Ks colour index
65- 68 A4 --- SpType Spectral type
70- 72 A3 --- Sel [Yes No] Indicates whether the (J-H, H-Ks)
colors meet our criteria
74- 99 A26 --- Com Comments (1)
--------------------------------------------------------------------------------
Note (1): Notes on individual stars:
1: Cataloged by Gizis, Reid, & Hawley, 2002, Cat. J/AJ/123/3356
2: Included in Paper III of the present series (Cruz & Reid, 2002,
Cat. J/AJ/123/2828)
3: Identified as a nearby star in Paper III, Cruz et al., 2002,
Cat. J/AJ/123/2828 and by McCaughrean, Scholz, & Lodieu,
2002A&A...390L..27M 2002A&A...390L..27M
4: Binary star with separation 5; 2MASS photometry unreliable.
5: Binary companion of LP 375-27 (mr=12.0), Δ=3";
2MASS photometry unreliable.
6: Binary companion of G148-8 (mr=14.9), Δ=4.5";
2MASS photometry unreliable.
7: Binary companion of BD+25 2621 (mr=11.0), Δ=4";
2MASS photometry unreliable.
8: Misidentification; no evidence of motion, probably a background giant.
9: LP 862-26 is not an M dwarf.
10: Inconsistent optical and infrared photometry; both stars are
merged with red field stars in the 2MASS scans.
11: Not identified as a binary by Luyten, but clearly elongated on
both UKST/SERC and 2MASS images; 2MASS photometry unreliable.
12: Merged with a field star in the 2MASS scans, and photometry
correspondingly unreliable. UBV photometry by Ryan
(1992AJ....104.1144R 1992AJ....104.1144R) indicates G-type colors. Note that SIMBAD
has separate listings for this star under the LP and Lowell names.
13: Binary companion of LP 878-90 (mr=14.2), Δ=4";
2MASS photometry unreliable.
14: Binary companion of BD-10 6203A (mr=7.8), Δ=3";
2MASS photometry unreliable.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [LSR]
4- 13 A10 --- LSR Name in LSR (Cat. J/AJ/124/1190)
15- 18 F4.1 mag Rmag The R band magnitude
20- 23 F4.2 mag R-J ? The (R-J) color
25 A1 --- l_Jmag Limit flag on Jmag
26- 31 F6.3 mag Jmag The 2MASS J band magnitude
33- 37 F5.3 mag e_Jmag ? Error in Jmag
39 A1 --- l_Hmag Limit flag on Hmag
40- 45 F6.3 mag Hmag The 2MASS H band magnitude
47- 51 F5.3 mag e_Hmag ? Error in Hmag
53 A1 --- l_Ksmag Limit flag on Ksmag
54- 59 F6.3 mag Ksmag The 2MASS Ks band magnitude
61- 65 F5.3 mag e_Ksmag ? Error in Ksmag
67- 71 F5.2 --- HR The R-band reduced proper motion
H = Rmag + 5 + 5logµ
73- 80 A8 --- Class Classification
82- 93 A12 --- Com Additional comments (1)
--------------------------------------------------------------------------------
Note (1): Spectral types are taken from Lepine, Rich & Shara (2003, Cat.
J/AJ/125/1598), except for LSR0510, LSR0539, LSR0602 (this paper)
and LSR1835 (Reid et al., 2003AJ....125..354R 2003AJ....125..354R)
1 = These white dwarfs lie within the area covered by the 2MASS Second
Incremental Data Release, but are not detected
2 = For further details, see Hambly et al. (1997ApJ...489L.157H 1997ApJ...489L.157H)
3 = LSR0510+2713 - correct position is RA = 5:10:20.1, DE = +27:14:4)
4 = This M8.5 dwarf lies only 5.67 parsecs from the Sun (Reid et al.,
2003AJ....125..354R 2003AJ....125..354R)
5 = LSR1928-0200B - correct position is RA = 19:28:13.3, DE = -2:0:25)
6 = Further details are given in Lowrance et al. (2003ApJ...584L..95L 2003ApJ...584L..95L).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Reid & Cruz, Paper I 2002AJ....123.2806R 2002AJ....123.2806R, Cat. J/AJ/123/2806
Reid et al., Paper II 2002AJ....123.2822R 2002AJ....123.2822R, Cat. J/AJ/123/2822
Cruz & Reid, Paper III 2002AJ....123.2828C 2002AJ....123.2828C, Cat. J/AJ/123/2828
Reid et al., Paper IV 2003AJ....125..354R 2003AJ....125..354R
Cruz et al., Paper V 2003AJ....126.2421C 2003AJ....126.2421C, Cat. J/AJ/126/2421
Reid et al., Paper VII 2003AJ....126.3007R 2003AJ....126.3007R, Cat. J/AJ/126/3007
Reid et al., Paper VIII 2004AJ....128..463R 2004AJ....128..463R, Cat. J/AJ/128/463
Cruz et al., Paper IX 2007AJ....133..439C 2007AJ....133..439C, Cat. J/AJ/133/439
Reid et al., Paper X 2008AJ....136.1290R 2008AJ....136.1290R, Cat. J/AJ/136/1290
Reid et al., Paper XI 2007AJ....133.2825R 2007AJ....133.2825R, Cat. J/AJ/133/2825
Cruz et al., Paper XII 2018AJ....155...34C 2018AJ....155...34C
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 12-Jan-2004