INTRINSIC COLORS, TEMPERATURES, AND BOLOMETRIC CORRECTIONS OF PRE-MAIN-SEQUENCE STARS

By M. Pecaut, Eric Mamajek. 2013

1,679 citations recorded by the source corpus.

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 WISEW1, 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 ≃100 K 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.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/60bf49bc4c821e2183ab53755b8bd977f1bd629a

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In Astronomy and Astrophysics

1. D. Charbonneau
2. Michael C. Liu
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4. Timothy Morton
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In Instrumentation

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Citations in the corpus

• Stellar and substellar companions of nearby stars from Gaia DR2 (2018, methodology): “The spectral type of the companion determined by Hale (1994) corresponds to an M2V star, of a mass of m2 ≈ 0.44 ± 0.05 M (Pecaut & Mamajek 2013).”
• BANYAN. VII. A NEW POPULATION OF YOUNG SUBSTELLAR CANDIDATE MEMBERS OF NEARBY MOVING GROUPS FROM THE BASS SURVEY (2015, methodology): “These standards were identified from the list maintained by Eric Mamajek3 (Boeshaar, P. C. 1976; Kirkpatrick et al. 1991; Pecaut & Mamajek 2013) and their spectra were downloaded from the IRTF spectral library4.”
• SOPHIE velocimetry of Kepler transit candidates XVII. The physical properties of giant exoplanets within 400 days of period (2015, methodology): “We estimated the (B-V) of the host stars based on their atmospheric parameters reported by Huber et al. (2014) and the calibration from Pecaut & Mamajek (2013).”
• Mind Your Ps and Qs: The Interrelation between Period (P) and Mass-ratio (Q) Distributions of Binary Stars (2016, methodology): “We then calculate the near-infrared magnitude H according to the temperature-dependent color indices (V − H) reported in Pecaut & Mamajek (2013).”
• 197 CANDIDATES AND 104 VALIDATED PLANETS IN K2's FIRST FIVE FIELDS (2016, methodology): “We estimate approximate spectral types (SpTs) using tabulated photometric relations (Kraus & Hillenbrand 2007; Pecaut & Mamajek 2013; Rodriguez et al. 2013) and convert SpTs into stellar radii (R*) based on interferometric studies (Boyajian et al. 2012).”
• Peering into the Dark Side: Magnesium Lines Establish a Massive Neutron Star in PSR J2215+5135 (2018, background): “These correspond to effective temperatures for the cold (“night”) and hot (“day”) sides of TN=5660 +260 −380 K and TD=8080 +470 −280 K, respectively (Pecaut & Mamajek 2013).”
• Discovery of a warm, dusty giant planet around HIP 65426 (2017, methodology): “Effective temperatures and reddening have been derived from spectral types using the calibration of Pecaut & Mamajek (2013).”
• The VLT-FLAMES Tarantula Survey XXVII. Physical parameters of B-type main-sequence binary systems in the Tarantula nebula (2017, neutral): “5 V, the spectral type versus magnitude calibrations of Walborn (1972) and Pecaut & Mamajek (2013) would imply a B -magnitude di ff erence of 0.8-0.9 and a secondary flux contribution of approximately 30%, in reasonable agreement with that estimated above.”
• AN EMPIRICAL CALIBRATION TO ESTIMATE COOL DWARF FUNDAMENTAL PARAMETERS FROM H-BAND SPECTRA (2014, background): “It has also been shown that latetype dwarfs may have different spectral types in the optical and infrared (e.g. Rojas-Ayala et al. 2012; Pecaut & Mamajek 2013; Newton et al. 2014).”
• A STELLAR CENSUS OF THE TUCANA–HOROLOGIUM MOVING GROUP (2014, background): “The dwarf and young-star temperature scales of Pecaut & Mamajek (2013) both fall between these limits.”
• A NEARBY M STAR WITH THREE TRANSITING SUPER-EARTHS DISCOVERED BY K2 (2015, methodology): “5±0.5, determined 16 https://github.com/awmann/Teff_rad_mass_lum to a half-subtype scale and assuming a sequence K5-K7M0 (i.e., without the K8 and K9 subdivisions of Pecaut & Mamajek 2013).”
• THE KEPLER FOLLOW-UP OBSERVATION PROGRAM. I. A CATALOG OF COMPANIONS TO KEPLER STARS FROM HIGH-RESOLUTION IMAGING (2016, methodology): “To derive an estimate of this ratio, we used the table with colors and effective temperatures for dwarf stars from Pecaut & Mamajek (2013) and assumed that primary and secondary stars are bound.”
• The star formation history and accretion-disc fraction among the K-type members of the Scorpius–Centaurus OB association (2016, methodology): “We use the same spectral standards and classification criteria as described in Pecaut & Mamajek (2013).”
• Stellar Flares from the First TESS Data Release: Exploring a New Sample of M Dwarfs (2019, methodology): “If only the Teff is available, we estimate R? using the updated values from Pecaut & Mamajek (2013)2 to then calculate L?.”
• The stellar rotation–activity relationship in fully convective M dwarfs (2018, methodology): “Converting the V − Ks colours to Teff using the data from Pecaut & Mamajek (2013) and converting these to stellar mass using a 1-Gyr iscohrone from Siess et al. (2000), we can also parametrize τ in terms of stellar mass (see Table 2) and fit a polynomial relationship of the form log τ =…”
• PLANETARY CANDIDATES FROM THE FIRST YEAR OF THE K2 MISSION (2015, methodology): “…temperature for each target from the star’s colors using either empirical relations from Boyajian et al. (2013), Casagrande et al. (2008), or González Hernández & Bonifacio (2009), or by interpolating color temperature relations from Eric Mamajek’s spectral type table8 (Pecaut & Mamajek 2013).”
• A self-consistent, absolute isochronal age scale for young moving groups in the solar neighbourhood (2015, methodology): “Following Pecaut & Mamajek (2013), for SACY objects brighter than V = 12 mag we adopt an uncertainty of σV = 0.01 mag, whereas for fainter sources we again adopt the rather conservative σV = 0.1 mag.”