New photometry and spectra OFAB Doradus C: An accurate mass determination of a young low-mass object with theoretical evolutionary tracks

Laird M Close, Niranjan Thatte, Eric L. Nielsen, Roberto Abuter, Fraser Clarke, Matthias Tecza

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

We present new photometric and spectroscopic measurements for the unique, young, low-mass evolutionary track calibrator AB Dor C. While the new K s photometry is similar to that we have previously published, the spectral type is found to be much earlier. Based on new H and K IFS spectra of AB Dor C from Thatte et al. (Paper I), we adopt a spectral type of M5.5 ±1.0 for AB Dor C. This is considerably earlier than the M8 ±1 previously estimated by Close et al. and Nielsen et al. yet is consistent with the M6 ±1 independently derived by Luhman & Potter. However, the spectrum presented in Paper I and analyzed here is a significant improvement over any previous spectrum of AB Dor C. We also present new astrometry for the system, which further supports a 0.090 ±0.005 M mass for the system. Once armed with an accurate spectrum and Ks flux, we find L = 0.0021 ±0.0005 L and Teff = 2925-145+170 K for AB Dor C. These values are consistent with a ∼75 Myr, 0.090 ±0.005 M object like AB Dor C according to the DUSTY evolutionary tracks. Hence, masses can be estimated from the H-R diagram with the DUSTY tracks for young low-mass objects such as AB Dor C. However, we cautiously note that underestimates of the mass from the tracks can occur if one lacks a proper (continuum-preserved) spectrum or is relying on near-infrared fluxes alone.

Original languageEnglish (US)
Pages (from-to)736-743
Number of pages8
JournalAstrophysical Journal
Volume665
Issue number1 PART 1
DOIs
StatePublished - Aug 10 2007

Fingerprint

photometry
astrometry
near infrared
diagram
diagrams
young
continuums

Keywords

  • Binaries: general
  • Instrumentation: adaptive optics
  • Stars: evolution
  • Stars: formation stars: individual (AB Doradus C)
  • Stars: low-mass, brown dwarfs

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

New photometry and spectra OFAB Doradus C : An accurate mass determination of a young low-mass object with theoretical evolutionary tracks. / Close, Laird M; Thatte, Niranjan; Nielsen, Eric L.; Abuter, Roberto; Clarke, Fraser; Tecza, Matthias.

In: Astrophysical Journal, Vol. 665, No. 1 PART 1, 10.08.2007, p. 736-743.

Research output: Contribution to journalArticle

Close, Laird M ; Thatte, Niranjan ; Nielsen, Eric L. ; Abuter, Roberto ; Clarke, Fraser ; Tecza, Matthias. / New photometry and spectra OFAB Doradus C : An accurate mass determination of a young low-mass object with theoretical evolutionary tracks. In: Astrophysical Journal. 2007 ; Vol. 665, No. 1 PART 1. pp. 736-743.
@article{651182f988aa4bd6a5a5655f91db8c79,
title = "New photometry and spectra OFAB Doradus C: An accurate mass determination of a young low-mass object with theoretical evolutionary tracks",
abstract = "We present new photometric and spectroscopic measurements for the unique, young, low-mass evolutionary track calibrator AB Dor C. While the new K s photometry is similar to that we have previously published, the spectral type is found to be much earlier. Based on new H and K IFS spectra of AB Dor C from Thatte et al. (Paper I), we adopt a spectral type of M5.5 ±1.0 for AB Dor C. This is considerably earlier than the M8 ±1 previously estimated by Close et al. and Nielsen et al. yet is consistent with the M6 ±1 independently derived by Luhman & Potter. However, the spectrum presented in Paper I and analyzed here is a significant improvement over any previous spectrum of AB Dor C. We also present new astrometry for the system, which further supports a 0.090 ±0.005 M⊙ mass for the system. Once armed with an accurate spectrum and Ks flux, we find L = 0.0021 ±0.0005 L⊙ and Teff = 2925-145+170 K for AB Dor C. These values are consistent with a ∼75 Myr, 0.090 ±0.005 M⊙ object like AB Dor C according to the DUSTY evolutionary tracks. Hence, masses can be estimated from the H-R diagram with the DUSTY tracks for young low-mass objects such as AB Dor C. However, we cautiously note that underestimates of the mass from the tracks can occur if one lacks a proper (continuum-preserved) spectrum or is relying on near-infrared fluxes alone.",
keywords = "Binaries: general, Instrumentation: adaptive optics, Stars: evolution, Stars: formation stars: individual (AB Doradus C), Stars: low-mass, brown dwarfs",
author = "Close, {Laird M} and Niranjan Thatte and Nielsen, {Eric L.} and Roberto Abuter and Fraser Clarke and Matthias Tecza",
year = "2007",
month = "8",
day = "10",
doi = "10.1086/518207",
language = "English (US)",
volume = "665",
pages = "736--743",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1 PART 1",

}

TY - JOUR

T1 - New photometry and spectra OFAB Doradus C

T2 - An accurate mass determination of a young low-mass object with theoretical evolutionary tracks

AU - Close, Laird M

AU - Thatte, Niranjan

AU - Nielsen, Eric L.

AU - Abuter, Roberto

AU - Clarke, Fraser

AU - Tecza, Matthias

PY - 2007/8/10

Y1 - 2007/8/10

N2 - We present new photometric and spectroscopic measurements for the unique, young, low-mass evolutionary track calibrator AB Dor C. While the new K s photometry is similar to that we have previously published, the spectral type is found to be much earlier. Based on new H and K IFS spectra of AB Dor C from Thatte et al. (Paper I), we adopt a spectral type of M5.5 ±1.0 for AB Dor C. This is considerably earlier than the M8 ±1 previously estimated by Close et al. and Nielsen et al. yet is consistent with the M6 ±1 independently derived by Luhman & Potter. However, the spectrum presented in Paper I and analyzed here is a significant improvement over any previous spectrum of AB Dor C. We also present new astrometry for the system, which further supports a 0.090 ±0.005 M⊙ mass for the system. Once armed with an accurate spectrum and Ks flux, we find L = 0.0021 ±0.0005 L⊙ and Teff = 2925-145+170 K for AB Dor C. These values are consistent with a ∼75 Myr, 0.090 ±0.005 M⊙ object like AB Dor C according to the DUSTY evolutionary tracks. Hence, masses can be estimated from the H-R diagram with the DUSTY tracks for young low-mass objects such as AB Dor C. However, we cautiously note that underestimates of the mass from the tracks can occur if one lacks a proper (continuum-preserved) spectrum or is relying on near-infrared fluxes alone.

AB - We present new photometric and spectroscopic measurements for the unique, young, low-mass evolutionary track calibrator AB Dor C. While the new K s photometry is similar to that we have previously published, the spectral type is found to be much earlier. Based on new H and K IFS spectra of AB Dor C from Thatte et al. (Paper I), we adopt a spectral type of M5.5 ±1.0 for AB Dor C. This is considerably earlier than the M8 ±1 previously estimated by Close et al. and Nielsen et al. yet is consistent with the M6 ±1 independently derived by Luhman & Potter. However, the spectrum presented in Paper I and analyzed here is a significant improvement over any previous spectrum of AB Dor C. We also present new astrometry for the system, which further supports a 0.090 ±0.005 M⊙ mass for the system. Once armed with an accurate spectrum and Ks flux, we find L = 0.0021 ±0.0005 L⊙ and Teff = 2925-145+170 K for AB Dor C. These values are consistent with a ∼75 Myr, 0.090 ±0.005 M⊙ object like AB Dor C according to the DUSTY evolutionary tracks. Hence, masses can be estimated from the H-R diagram with the DUSTY tracks for young low-mass objects such as AB Dor C. However, we cautiously note that underestimates of the mass from the tracks can occur if one lacks a proper (continuum-preserved) spectrum or is relying on near-infrared fluxes alone.

KW - Binaries: general

KW - Instrumentation: adaptive optics

KW - Stars: evolution

KW - Stars: formation stars: individual (AB Doradus C)

KW - Stars: low-mass, brown dwarfs

UR - http://www.scopus.com/inward/record.url?scp=34548297816&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34548297816&partnerID=8YFLogxK

U2 - 10.1086/518207

DO - 10.1086/518207

M3 - Article

AN - SCOPUS:34548297816

VL - 665

SP - 736

EP - 743

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1 PART 1

ER -