J/ApJS/208/9 Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
Intrinsic colors, temperatures, and bolometric corrections of
pre-main-sequence stars.
Pecaut M.J., Mamajek E.E.
<Astrophys. J. Suppl. Ser., 208, 9 (2013)>
=2013ApJS..208....9P 2013ApJS..208....9P
ADC_Keywords: Photometry, UBVRI ; Photometry, infrared ; Spectral types ;
Stars, pre-main sequence ; Associations, stellar
Keywords: open clusters and associations: individual (η Cha cluster,
TW Hydra Association, β Pic Moving Group,
Tucana-Horologium Association) -
stars: fundamental parameters - stars: pre-main sequence
Abstract:
We present an analysis of the intrinsic colors and temperatures of
5-30 Myr old pre-main-sequence (pre-MS) stars using the F0- through
M9-type members of nearby, negligibly reddened groups: the η Cha
cluster, the TW Hydra Association, the β Pic Moving Group, and
the Tucana-Horologium Association. To check the consistency of
spectral types from the literature, we estimate new spectral types for
52 nearby pre-MS stars with spectral types F3 through M4 using optical
spectra taken with the SMARTS 1.5 m telescope. Combining these new
types with published spectral types and photometry from the literature
(Johnson-Cousins BVIC, 2MASS JHKS and WISE W1, W2, W3, and W4), we
derive a new empirical spectral type-color sequence for 5-30 Myr old
pre-MS stars. Colors for pre-MS stars match dwarf colors for some
spectral types and colors, but for other spectral types and colors,
deviations can exceed 0.3 mag. We estimate effective temperatures
(Teff) and bolometric corrections (BCs) for our pre-MS star sample
through comparing their photometry to synthetic photometry generated
using the BT-Settl grid of model atmosphere spectra. We derive a new
Teff and BC scale for pre-MS stars, which should be a more
appropriate match for T Tauri stars than often-adopted dwarf star
scales. While our new Teff scale for pre-MS stars is within ≃100K
of dwarfs at a given spectral type for stars <G5, for G5 through K6,
the pre-MS stars are ∼250 K cooler than their MS counterparts. Lastly,
we present (1) a modern Teff, optical/IR color, and BC sequence for
O9V-M9V MS stars based on an extensive literature survey, (2) a
revised Q-method relation for dereddening UBV photometry of OB-type
stars, and (3) introduce two candidate spectral standard stars as
representatives of spectral types K8V and K9V.
Description:
Though the objects in our sample have published spectral types, they
are from a variety of sources and resolutions. In order to check the
consistency of spectral types in the literature, we obtain new
spectral types (table 3). We acquired low-resolution blue
(∼3700Å-5200Å) and red (∼5600Å-6900Å) optical spectra from
the SMARTS 1.5m telescope in Cerro Tololo, Chile for 52 members of
β Pic, TWA (TW Hydra Association) and η Cha. Observations
were made in queue mode with the RC spectrograph between 2011 February
and 2011 July.
We assembled the most precise photometry available from the literature
(table 1). All stars in our list have counterparts in the 2MASS Point
Source Catalog.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 205 148 Spectral types and optical/near-IR photometry for
young, nearby, moving group members
table3.dat 51 52 Observations and new spectral types
table4.dat 116 893 Synthetic color indices from BT-Settl and ATLAS9
models
table5.dat 91 66 Intrinsic colors of O9-M9 dwarfs and adopted Teff,
bolometric correction values
table6.dat 63 40 Intrinsic colors of 5-30Myr old stars and adopted
Teff, bolometric correction values
table9.dat 164 137 Teff, bolometric magnitudes, bolometric corrections,
and angular diameter estimates from SED fitting
refs.dat 138 54 References
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See also:
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
III/198 : Palomar/MSU nearby star spectroscopic survey (Hawley+ 1997)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
III/150 : Perkins Revised MK Types for the Cooler Stars (Keenan+ 1989)
III/135 : Henry Draper Catalogue and Extension (Cannon+ 1918-1924; ADC 1989)
III/123 : Dwarf K and M stars of small proper motion (Stephenson 1986)
III/13 : Vyssotsky's Catalogues 1950.0 (Vyssotsky+ 1943-58)
J/AJ/143/134 : Cand. members of β Pic/AB Dor groups (McCarthy+, 2012)
J/MNRAS/403/1949 : UBV(RcIc)JHK photometry of HIP nearby stars (Koen+, 2010)
J/ApJ/699/649 : Young M dwarfs within 25pc. I. (Shkolnik+, 2009)
J/AJ/132/866 : New M dwarfs in solar neighborhood (Riaz+, 2006)
J/AJ/132/161 : NStars project: The southern sample. I. (Gray+, 2006)
J/A+A/460/695 : Search for Associations Containing Young stars (Torres+, 2006)
J/other/ARA+A/42.685 : Young stars near the Sun (Zuckerman+, 2004)
J/AJ/105/1962 : K and M stars photometry (Weis, 1993)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Star name
25- 27 A3 --- Grp Group identifier (1)
29- 44 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs)
46- 56 A11 --- SpT MK spectral type
58- 59 I2 --- r_SpT [1/38] Reference on SpT (see refs.dat file)
61- 66 F6.3 mag Vmag [5.22/21.46]? Johnson V band magnitude
68- 72 F5.3 mag e_Vmag [0.01/0.1]? Uncertainty in Vmag
74- 78 F5.3 mag B-V [0.28/1.73]? Johnson color index B-V
80- 84 F5.3 mag e_B-V ? Uncertainty in B-V
86- 90 F5.3 mag V-Ic [0.33/3.76]? Johnson-Cousins color index V-Ic
92- 96 F5.3 mag e_V-Ic ? Uncertainty in V-Ic
98-105 A8 --- ORef Optical photometry reference(s)
(see refs.dat file)
107-112 F6.3 mag Jmag [5.26/15.35]? 2MASS J band magnitude (3)
114-118 F5.3 mag e_Jmag ? Uncertainty in Jmag
120-125 F6.3 mag Hmag [4.83/14.54]? 2MASS H band magnitude (3)
127-131 F5.3 mag e_Hmag ? Uncertainty in Hmag
133-138 F6.3 mag Ksmag [4.53/13.73]? 2MASS Ks band magnitude (3)
140-144 F5.3 mag e_Ksmag ? Uncertainty in Ksmag
146 A1 --- f_Ksmag [d] Ksmag excluded (4)
148-153 F6.3 mag W1mag [4.49/12.31]? WISE W1 band magnitude (5)
155-159 F5.3 mag e_W1mag ? Uncertainty in W1mag
161 A1 --- f_W1mag [d] W1mag excluded (4)
163-168 F6.3 mag W2mag [6.05/11.63]? WISE W2 band magnitude (5)
170-174 F5.3 mag e_W2mag ? Uncertainty in W2mag
176 A1 --- f_W2mag [d] W3mag excluded (4)
178-183 F6.3 mag W3mag [3.10/11.32]? WISE W3 band magnitude (5)
185-189 F5.3 mag e_W3mag ? Uncertainty in W3mag
191 A1 --- f_W3mag [d] W3mag excluded (4)
193-197 F5.3 mag W4mag [0.19/9.75]? WISE W4 band magnitude (5)
199-203 F5.3 mag e_W4mag ? Uncertainty in W4mag
205 A1 --- f_W4mag [d] W4mag excluded (4)
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Note (1): Group code as follows:
BP = β Pic Moving Group;
EC = η Cha Cluster;
TWA = TW Hydra Association;
TH = Tucana-Horologium Association.
Note (3): From the 2MASS All-Sky Point Source Catalog (Cutri et al. 2003,
Cat. II/246; Skrutskie et al. 2006, Cat. VII/233).
Note (4): d = Photometry excluded due to identified infrared excess
(Hutchinson et al. 1990A&A...234..230H 1990A&A...234..230H; Megeath et al.
2005ApJ...634L.113M 2005ApJ...634L.113M; Riaz et al. 2006, Cat. J/AJ/132/866;
Sicilia-Aguilar et al. 2009ApJ...701.1188S 2009ApJ...701.1188S; Rebull et al.
2008ApJ...681.1484R 2008ApJ...681.1484R; Gautier et al. 2008ApJ...683..813G 2008ApJ...683..813G;
Zuckerman et al. 2011ApJ...732...61Z 2011ApJ...732...61Z;
Schneider et al. 2012ApJ...754...39S 2012ApJ...754...39S, 2012ApJ...757..163S 2012ApJ...757..163S).
The binary pair HIP 10679 and HIP 10680 were studied in Rebull et al.
(2008ApJ...681.1484R 2008ApJ...681.1484R), with only HIP 10679 identified as having a 24
micron excess. However, they are separated by ∼14" and thus it is
likely that the HIP 10680 W4 photometry is contaminated by the HIP
10679 W4 excess, so we exclude the HIP 10680 W4 photometry as well.
Note (5): From WISE All Sky Data Release (Cutri & et al. 2012, Cat. II/311).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Object name
16- 17 A2 --- m_Name [AB ] Multiplicity index on Name
19 A1 --- f_Name [abc] Individual notes (1)
21- 29 A9 --- SpT Mk spectral type from this work
31- 38 A8 --- Cover Spectral coverage (Red/blue)
40- 50 A11 --- SpTl MK spectral type from literature
52- 53 I2 --- Ref [41/55] Reference code (see refs.dat file)
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Note (1): Flag as follows:
a = Our blue spectrum of this star was classified as G5V while our red
spectrum was classified as a K1V. Therefore we adopted an overall
spectral type of G5V,K1V.
b = Our spectrum of this star did not cover the Na doublet feature.
c = McCarthy & White (2012, Cat. J/AJ/143/134) were unable to detect Li in a
high-resolution spectrum of this star, casting doubt on its membership
in β Pic; however, we retain it as a member for the purposes of
this study.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 I5 K Teff [1400/50000] Effective temperature
7- 9 F3.1 [cm/s2] logg [3/5] Surface gravity
11- 16 F6.3 mag U-B [-1.194/4.978] Johnson color index U-B
18- 23 F6.3 mag B-V [-0.945/3.376] Johnson color index B-V
25- 30 F6.3 mag V-Ic [-0.344/8.421] Johnson-Cousins color index V-Ic
32- 37 F6.3 mag Rc-Ic [-0.219/3.433] Johnson-Cousins color index Rc-Ic
39- 44 F6.3 mag J-H [-0.132/1.916] 2MASS color index J-H
46- 51 F6.3 mag H-Ks [-0.11/1.344] 2MASS color index H-Ks
53- 58 F6.3 mag V-Ks [-1.035/14.184] Johnson-2MASS color index V-Ks
60- 65 F6.3 mag Ks-W1 [-0.085/1.379] 2MASS-WISE color index Ks-W1
67- 72 F6.3 mag Ks-W2 [-0.142/1.967] 2MASS-WISE color index Ks-W2
74- 79 F6.3 mag Ks-W3 [-0.241/2.652] 2MASS-WISE color index Ks-W3
81- 86 F6.3 mag Ks-W4 [-0.325/2.921] 2MASS-WISE color index Ks-W4
88- 93 F6.3 mag V-Vt [-0.42/1.09] Johnson-Tycho color index V-Vt
95-100 F6.3 mag Bt-Vt [-0.37/4.05] Johnson-Tycho color index B-Bt
102-107 F6.3 mag V-Hp [-0.18/3.19] Johnson-Hipparcos color index V-Hp
109-116 A8 --- Model Synthetic model source (ATLAS9 or BT-Sett1) (1)
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Note (1): Solar metallicity models. The BT-Settl model colors presented here
adopt the Asplund et al. (2009ARA&A..47..481A 2009ARA&A..47..481A) solar composition,
whereas the ATLAS9 model colors presented here adopt the Grevesse
& Sauval (1998SSRv...85..161G 1998SSRv...85..161G) solar composition.
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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- 5 A5 --- SpT MK spectral type
7- 11 I5 K Teff [2450/34000] Effective temperature
13- 17 F5.2 mag BCV [-5.73/0] The V band bolometric correction
19- 24 F6.3 mag U-B [-1.114/1.433]? Johnson color index U-B
26- 31 F6.3 mag B-V [-0.318/2.13]? Johnson color index B-V
33- 38 F6.3 mag V-Rc [-0.115/2.18]? Johnson-Cousins color index V-Rc
40- 45 F6.3 mag V-Ic [-0.369/4.6] Johnson-Cousins color index V-Ic
47- 52 F6.3 mag V-J [-0.765/7.617] Johnson-2MASS color index V-J
54- 59 F6.3 mag V-H [-0.929/8.366] Johnson-2MASS color index V-H
61- 66 F6.3 mag V-Ks [-1/8.85] Johnson-2MASS color index V-Ks
68- 72 F5.3 mag K-W1 [0.023/0.212]? Johnson-WISE color index K-W1
74- 78 F5.3 mag K-W2 [0.001/0.38]? Johnson-WISE color index K-W2
80- 85 F6.3 mag K-W3 [-0.021/0.544]? Johnson-WISE color index K-W3
87- 91 F5.3 mag K-W4 [0.044/0.669]? Johnson-WISE color index K-W4
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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- 2 A2 --- SpT MK spectral type
4- 7 I4 K Teff [2880/7280]? Effective temperature
9- 12 F4.2 mag B-V [0.28/1.65]? Johnson color index B-V
14- 17 F4.2 mag V-Ic [0.34/3.31]? Johnson-Cousins color index V-Ic
19- 22 F4.2 mag V-Ks [0.73/9.8] Johnson-2MASS color index V-Ks
24- 27 F4.2 mag J-H [0.11/0.7] 2MASS color index J-H
29- 32 F4.2 mag H-Ks [0.06/0.47] 2MASS color index H-Ks
34- 37 F4.2 mag Ks-W1 [0.04/0.49] Johnson-WISE color index Ks-W1
39- 42 F4.2 mag Ks-W2 [0.03/1.05] Johnson-WISE color index Ks-W2
44- 47 F4.2 mag Ks-W3 [0/1.13] Johnson-WISE color index Ks-W3
49- 52 F4.2 mag Ks-W4 [0.08/0.62]? Johnson-WISE color index Ks-W4
54- 58 F5.2 mag BCV [-3.21/0.01]? The V band bolometric correction
60- 63 F4.2 mag BCJ [0.57/2.01]? The J band bolometric correction
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Object name (1)
25- 40 A16 --- 2MASS 2MASS identifier
42- 45 I4 K Teff1 [2118/7275] BT-Settl effective temperature (2)
47- 49 I3 K e_Teff1 Uncertainty in Teff1
51- 53 I3 uas Diam1 [46/790] BT-Settl angular diameter (θ)
55 I1 uas e_Diam1 Uncertainty in Diam1
57- 61 F5.2 mag BCV1 ? BT-Settl V band bolometric correction
63- 66 F4.2 mag e_BCV1 ? Uncertainty in BCV1
68- 71 F4.2 mag BCJ1 [0.4/2.1] BT-Settl J band bolometric correction
73- 76 F4.2 mag e_BCJ1 Uncertainty in BCJ1
78- 82 F5.2 mag mbol1 [5.2/15.7] BT-Settl apparent bolometric magnitude
84- 87 F4.2 mag e_mbol1 Uncertainty in mbol1
89- 94 F6.3 [Lsun] logL1 [-2.75/0.88]? BT-Settl log luminosity
96-100 F5.3 [Lsun] e_logL1 ? Uncertainty in logL1
102 A1 --- n_logL1 [abc] Reference of parallax used for logL1 (3)
104-107 I4 K Teff2 [3572/7251]? Kurucz effective temperature (2)
109-110 I2 K e_Teff2 ? Uncertainty in Teff2
112-114 I3 uas Diam2 [89/753]? Kurucz angular diameter (θ)
116-117 I2 uas e_Diam2 ? Uncertainty in Diam2
119-123 F5.2 mag BCV2 ? Kurucz V band bolometric correction
125-128 F4.2 mag e_BCV2 ? Uncertainty in BCV2
130-133 F4.2 mag BCJ2 [0.5/1.9]? Kurucz J band bolometric correction
135-138 F4.2 mag e_BCJ2 ? Uncertainty in BCJ2
140-144 F5.2 mag mbol2 [5.2/11.3]? Kurucz apparent bolometric magnitude
146-149 F4.2 mag e_mbol2 ? Uncertainty in mbol2
151-156 F6.3 [Lsun] logL2 [-1.14/0.87]? Kurucz log luminosity
158-162 F5.3 [Lsun] e_logL2 ? Uncertainty in logL2
164 A1 --- n_logL2 [a] Reference of parallax used for logL2 (3)
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Note (1): We have used a weighted mean distance of 94.3±1.2pc for η Cha
cluster members. For HD 139084B, HD 164249B, AZ Cap, and HD 222259B
we have adopted parallaxes from their brighter companions.
Note (2): Teff values were fit at log(g)=4.3.
Note (3): Flag as follows:
a = logL estimates use parallaxes from Weinberger et al. (2013ApJ...762..118W 2013ApJ...762..118W).
b = logL estimate uses parallax from Teixeira et al. (2008A&A...489..825T 2008A&A...489..825T).
c = logL estimate uses parallax from Teixeira et al. (2009A&A...503..281T 2009A&A...503..281T).
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref [1/55] Reference code
4- 22 A19 --- BibCode Bibcode
24- 45 A22 --- Aut Author's name(s)
47-138 A92 --- Comm Comment
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 30-Sep-2013