J/AJ/123/2828 Spectroscopy of northern NLTT stars (Cruz+, 2002)
Meeting the cool neighbors. III. Spectroscopy of northern NLTT stars.
Cruz K.L., Reid I.N.
<Astron. J. 123, 2828 (2002)>
=2002AJ....123.2828C 2002AJ....123.2828C
ADC_Keywords: Stars, late-type ; Stars, dwarfs ; Photometry, infrared ;
Spectroscopy ; Stars, distances
Keywords: Galaxy: stellar content - solar neighborhood - stars: distances -
stars: late-type
Abstract:
We present initial results of an all-sky search for late-type dwarfs
within 20pc of the Sun using the New Luyten Two-Tenths (NLTT) catalog
cross-referenced with the Two Micron All Sky Survey (2MASS) database.
The results were obtained with low-resolution optical spectroscopic
follow-up of candidate nearby stars as a preliminary test of our
methodology. MJ, derived using spectral indices, and 2MASS J are
used to estimate distances. Out of the 70 objects observed, 28 are
identified as previously unrecognized objects within 25pc of the Sun,
and up to 19 of these are within 20pc. One, LP 647-13, is an M9-type
dwarf at 10.5pc, making it one of the four closest M9 dwarfs
currently known. We also discuss the chromospheric activity of the
observed dwarfs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 125 28 Previously known objects in our sample of NLTT
targets
table2.dat 139 38 Data for targets included in NLTT sample 1
table3.dat 137 37 Data for targets not included in NLTT sample 1
table5.dat 104 86 Spectral Indices for All Targets and Standards
table6.dat 57 43 Activity
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See also:
I/98 : NLTT Catalogue (Luyten, 1979)
B/2mass : The 2MASS database (IPAC/UMass, 2000)
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/126/2421 : 2MASS-Selected sample of ultracool dwarfs (Cruz+, 2003)
J/AJ/126/2449 : Nearby ultracool dwarfs in galactic plane (Reid+, 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
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Bytes Format Units Label Explanations
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1- 10 A10 --- NLTT Name from NLTT (I/98) Catalogue (1)
12 A1 --- n_NLTT [a-d] Note on NLTT (2)
14- 26 A13 --- OName Other name
28- 29 I2 h RAh 2MASS source right ascension (J2000.0)
31- 32 I2 min RAm 2MASS source right ascension (J2000.0)
34- 38 F5.2 s RAs 2MASS source right ascension (J2000.0)
40 A1 --- DE- 2MASS source declination sign (J2000.0)
41- 42 I2 deg DEd 2MASS source declination (J2000.0)
44- 45 I2 arcmin DEm 2MASS source declination (J2000.0)
47- 51 F5.2 arcsec DEs 2MASS source declination (J2000.0)
53- 57 F5.2 mag VMAG ? Absolute V magnitude
59- 60 I2 --- r_VMAG ? Reference for VMAG (3)
62- 66 F5.2 mag JMAG ? Absolute J magnitude, obtained using our
distance estimates
68- 71 F4.2 mag e_JMAG ? rms uncertainty on JMAG
73- 76 F4.1 mag rmag ? r magnitude, given in the NLTT
78- 83 F6.3 mag Jmag ? J magnitude form 2MASS
85- 90 F6.3 mag Hmag ? H magnitude form 2MASS
92- 97 F6.3 mag Ksmag ? Ks magnitude form 2MASS
99-104 F6.2 pc Dist ? Distance
106-110 F5.2 pc e_Dist ? rms uncertainty on Dist
112-113 I2 --- r_Dist ? Source of trigonometric parallax (4) (3)
115-118 A4 --- r_Dist2 ? Source of photometry,
separated by comma (4) (3)
120-123 A4 --- SpType Spectral type
125 I1 --- r_SpType ? Reference for SpType (4)
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Note (1): Identifiers are Luyten-Palomar (LP), Ross (R) and
Bonner Durchmusterung (BD)
Note (2): Individual notes:
a: Used TiO 5 and CaH 2 indices and our calibrations to find JMAG
and distance
b: Distance based on trigonometric parallax for companion, Gl 53.1A
c: The system made up of two NLTT objects, LP 469-118 and its close
companion G35-27, are unresolved by 2MASS and the photometry is
not reliable
d: Used TiO 5 and CaH 2 indices and our calibrations to find MJ and
a distance estimate. Final estimate is average of this value with
estimates based on optical photometry.
Note (3): Source upon which the distance estimate is based.
Note (4): References:
1: Harrington et al., 1985AJ.....90..123H 1985AJ.....90..123H
2: PMSU1, Reid et al., 1995, Cat. III/198
3: Gizis et al., 2000AJ....120.1085G 2000AJ....120.1085G
4: Gizis & Reid, 1997, Cat. J/PASP/109/849
5: ESA, HIP, 1997, Cat. I/239
6: Gliese & Jahreiss, 1991, Cat. VII/155
7: Harrington & Dahn, 1980AJ.....85..454H 1980AJ.....85..454H
8: Monet et al., 1992, Cat. J/AJ/103/638
9: Dahn et al., 2000, ASP Conf. 212, 74
10: Tinney, Mould, & Reid 1993
11: Reid, 1993MNRAS.265..785R 1993MNRAS.265..785R
12: Weis, 1991AJ....101.1882W 1991AJ....101.1882W
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Byte-by-byte Description of file: table2.dat table3.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- NLTT Name from NLTT (I/98) Catalogue (1)
11 A1 --- n_NLTT [d-k] Individual note (2)
13- 20 A8 --- OName Other name
22- 23 I2 h RAh 2MASS source right ascension (J2000.0)
25- 26 I2 min RAm 2MASS source right ascension (J2000.0)
28- 32 F5.2 s RAs 2MASS source right ascension (J2000.0)
34 A1 --- DE- 2MASS source declination sign (J2000.0)
35- 36 I2 deg DEd 2MASS source declination (J2000.0)
38- 39 I2 arcmin DEm 2MASS source declination (J2000.0)
41- 45 F5.2 arcsec DEs 2MASS source declination (J2000.0)
47- 51 F5.2 mag rmag ? r magnitude, given in the NLTT
52- 57 F6.3 mag Jmag ? J magnitude form 2MASS
59- 64 F6.3 mag Hmag ? H magnitude form 2MASS
66- 71 F6.3 mag Ksmag ? Ks magnitude form 2MASS
73- 77 F5.2 mag JMAGTiO5 ? Predicted absolute J magnitude based on the
spectral index TiO 5
TiO 5 = F(7126-7135Å)/F(7042-7046Å)
79- 82 F4.2 mag e_JMAGTiO5 ? rms uncertainty on JMAGTiO5
83 A1 --- n_JMAGTiO5 [a] Note (3)
85- 89 F5.2 mag JMAGCaH2 ? Predicted absolute J magnitude based on the
spectral index CaH 2
CaH 2 = F(6814-6846Å)/F(7042-7046Å)
91- 94 F4.2 mag e_JMAGCaH2 ? rms uncertainty on JMAGCaH2
95 A1 --- n_JMAGCaH2 [ab] Note (3)
97-101 F5.2 mag JMAGCaOH ? Predicted absolute J magnitude based on the
spectral index CaOH
CaOH = F(6230-6240Å)/F(6345-6354Å)
103-106 F4.2 mag e_JMAGCaOH ? rms uncertainty on JMAGCaOH
107 A1 --- n_JMAGCaOH [abc] Note (3)
109-113 F5.2 mag JMAG ? Final absolute J magnitude estimate
115-118 F4.2 mag e_JMAG ? rms uncertainty on JMAG
120-124 F5.1 pc Dist ? Photometric estimated distance
126-129 F4.1 pc e_Dist ? rms uncertainty on Dist
130 A1 --- n_Dist [*] Note (4)
132-137 A6 --- SpType Spectral type
139 A1 --- Flag [YN?] Flag that indicates whether the object
lies within our distance limit of 20 pc ("Y")
within 1 σ of the boundary ("?"), or
beyond the limit ("N"), for table2.dat only
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Note (1): Identifiers are Luyten-Palomar (LP), Ross (R) and
Bonner Durchmusterung (BD)
Note (2): Note on Name:
--- (table2.dat):
d: LP 31-301 and LP 31-302 form a wide binary system with a
separation of 5". The band-strength indices measured for the
brighter star fall in the ambiguous range, and we quote two
distances estimates. The distance derived for the fainter star,
LP 31-302, is consistent with the shorter distance of 14.7±1.2pc
e: Also identified by Phan-Bao et al., 2001A&A...380..590P 2001A&A...380..590P
--- (table3.dat):
f: Has common proper motion with G36-39
g: Has common proper motion with LP 831-38
h: Has common proper motion with G8-48
i: Candidate M subdwarf; see Chapt. 4.1 and 5.2
j: LP 880-441 and LP 880-442 form a wide binary system with
separation of 8". As with LP 31-301/302, the brighter star has
indices that fall within the region of ambiguity in Fig. 4.
However, in this case the distance estimate to the fainter star
is not sufficiently accurate to provide an improved distance
estimate to the system.
k: Has common proper motion with G4-5
Note (3): Note on JMAG estimation:
a: This predicted value of JMAG is double-valued, and the result
closest to the predictions based on other indices was used as
our estimate JMAG
b: This predicted value of JMAG is double-valued, and both
predictions are more than 3σ from either of the other
predictions. Neither is incorporated in calculating the final
value JMAG
c: This value is more than 3σ from either of the other
predictions and was not used to estimate JMAG
Note (4): *: See text for explanation of distance estimate.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- NLTT The object name
12- 31 A20 --- 2MASS The 2MASS name
33- 37 F5.3 --- CaOH The CaOH spectral index (1)
39- 43 F5.3 --- Ha The Hα spectral index (2)
45- 49 F5.3 --- CaH1 The CaH 1 spectral index (3)
51- 55 F5.3 --- CaH2 The CaH 2 spectral index (4)
57- 61 F5.3 --- CaH3 The CaH 3 spectral index (5)
63- 67 F5.3 --- TiO-a The TiO-a spectral index (6)
69- 73 F5.3 --- TiO2 The TiO 2 spectral index (7)
75- 79 F5.3 --- TiO3 The TiO 3 spectral index (8)
81- 85 F5.3 --- TiO4 The TiO 4 spectral index (9)
87- 91 F5.3 --- TiO5 The TiO 5 spectral index (10)
93- 97 F5.3 --- VO-a The VO-a spectral index (11)
99-103 F5.3 --- PC3 The PC3 spectral index (12)
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Note (1): Defined as the 6230-6240 Å flux divided by the 6345-6354 Å flux
Note (2): Defined as the 6560-6566 Å flux divided by the 6545-6555 Å flux
Note (3): Defined as the 6380-6390 Å flux divided by the average of the
6345-6355 Å & 6410-6430 Å flux
Note (4): Defined as the 6814-6846 Å flux divided by the 7042-7046 Å flux
Note (5): Defined as the 6960-6990 Å flux divided by the 7042-7046 Å flux
Note (6): Defined as the 7033-7048 Å flux divided by the 7058-7073 Å flux
Note (7): Defined as the 7058-7061 Å flux divided by the 7043-7046 Å flux
Note (8): Defined as the 7092-7097 Å flux divided by the 7079-7084 Å flux
Note (9): Defined as the 7130-7135 Å flux divided by the 7115-7120 Å flux
Note (10): Defined as the 7126-7135 Å flux divided by the 7042-7046 Å flux
Note (11): Defined as the sum of the 7350-7370 Å & 7550-7570 Å flux
divided by the 7430-7470 Å flux
Note (12): Defined as the 8230-8270 Å flux divided by the 7540-7580 Å flux
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- NLTT The object name
12- 31 A20 --- 2MASS The 2MASS name
33- 38 F6.2 10-18W/m2 FHa Hα flux in units of 10-15ergs/cm2/s
40- 44 F5.2 0.1nm EWHa Hα equivalent width in Angstroems
46- 50 F5.2 mag MBol Bolometric magnitude
52- 56 F5.2 --- logRat Log of the Hα to bolometric flux ratio
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History:
From electronic version of the journal
* 27-Aug-2003: in Table1, the negative sign for the declination of
LP 593- 68 = LHS 1604 has been added (the correct declination is:
03 51 00.03 -00 52 44.11)
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
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, Paper VI, 2003AJ....126.2449R 2003AJ....126.2449R, Cat. J/AJ/126/2449
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 Bauer [CDS] 21-Jun-2002