C.D.S. - SIMBAD4 rel 1.7 - 2020.07.14CEST19:46:13

2014A&A...566A..85S - Astronomy and Astrophysics, volume 566A, 85-85 (2014/6-1)

First spectroscopic observations of the substellar companion of the young debris disk star PZ Telescopii.


Abstract (from CDS):

In 2010 a substellar companion to the solar analog pre-main sequence star PZ Tel and member of the approximately 12Myr old β Pic moving group was found by high-contrast direct imaging independently by two teams. In order to determine the basic parameters of this companion more precisely and independent of evolutionary models, hence age-independent, we obtained follow-up spectroscopic observations of the primary and companion. We used the Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) at the Very Large Telescope Unit 4/Yepun of ESO's Paranal Observatory in the H+K band and processed the data using the spectral deconvolution technique. The resulting spectrum of the companion was then compared to a grid of Drift-Phoenix synthetic model spectra, a combination of a general-purpose model atmosphere code with a non-equilibrium, stationary cloud and dust model, using a χ2 minimization analysis. We find a best fitting spectral type of G6.5 for PZ Tel A. The extracted spectrum of the substellar companion, at a spatial position compatible with earlier orbit estimates, yields a temperature Teff=2500+138–115K, a visual extinction AV=0.53+0.84–0.53mag, a surface gravity of logg=3.50+0.51–0.30dex, and a metallicity at the edge of the grid of [M/H]=0.30–0.30dex. We derive a luminosity of log(Lbol/L)=-2.66+0.06–0.08, a radius of R =2.42+0.28–0.34RJup, and a mass of M=7.5+16.9–4.3MJup for the PZ Tel companion, which is consistent with most earlier estimates using photometry alone. Combining our results with evolutionary models, we find a best-fitting mass of about 21 Jupiter masses at an age corresponding to the recently determined lithium depletion age of 7+4–2Myr. Hence, the PZ Tel companion is most likely a wide brown dwarf companion in the 12+8–4Myr old β Pic moving group.

Abstract Copyright:

Journal keyword(s): brown dwarfs - stars: pre-main sequence - stars: atmospheres - planetary systems - planets and satellites: formation - stars: individual: PZ Tel

Simbad objects: 3

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Number of rows : 3

N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
1 NAME beta Pic Moving Group MGr 14 30 -42.0           ~ 557 0
2 V* PZ Tel BY* 18 53 05.8733807460 -50 10 49.901380086   9.22 8.342   7.464 G9IV 286 0
3 HD 179029 * 19 12 34.5412903219 -37 31 26.533195308   7.22 7.15     B5V 15 0

    Equat.    Gal    SGal    Ecl

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