J/ApJ/923/48 Discovery of an L dwarf co-moving BD+60 1417 (Faherty+, 2021)
A wide planetary mass companion discovered through the citizen science project
Backyard Worlds: Planet 9.
Faherty J.K., Gagne J., Popinchalk M., Vos J.M., Burgasser A.J.,
Schumann J., Schneider A.C., Kirkpatrick J.D., Meisner A.M., Kuchner M.J.,
Bardalez Gagliuffi D.C., Marocco F., Caselden D., Gonzales E.C.,
Rothermich A., Casewell S.L., Debes J.H., Aganze C., Ayala A., Hsu C.-C.,
Cooper W.J., Smart R.L., Gerasimov R., Theissen C.A.,
The Backyard Worlds: Planet 9 Collaboration
<Astrophys. J., 923, 48 (2021)>
=2021ApJ...923...48F 2021ApJ...923...48F
ADC_Keywords: Stars, brown dwarf; Stars, L-type; Stars, double and multiple;
Spectra, infrared; Spectra, optical; Stars, K-type
Keywords: Brown dwarfs ; L dwarfs ; Direct imaging ; Young star clusters ;
Astrometry ; Companion stars ; Substellar companion stars
Abstract:
Through the Backyard Worlds: Planet 9 citizen science project we
discovered a late-type L dwarf co-moving with the young K0 star
BD+60 1417 at a projected separation of 37" or 1662au. The
secondary-CWISER J124332.12+600126.2 (W1243)-is detected in both the
CatWISE2020 and 2MASS reject tables. The photometric distance and
CatWISE proper motion both match that of the primary within ∼1σ
and our estimates for a chance alignment yield a zero probability.
Follow-up near-infrared spectroscopy reveals W1243 to be a very red
2MASS (J-Ks=2.72), low surface gravity source that we classify as
L6-L8γ. Its spectral morphology strongly resembles that of
confirmed late-type L dwarfs in 10-150Myr moving groups as well as
that of planetary mass companions. The position on near- and
mid-infrared color-magnitude diagrams indicates the source is redder
and fainter than the field sequence, a telltale sign of an object with
thick clouds and a complex atmosphere. For the primary we obtained new
optical spectroscopy and analyzed all available literature information
for youth indicators. We conclude that the LiI abundance, its loci on
color-magnitude and color-color diagrams, and the rotation rate
revealed in multiple TESS sectors are all consistent with an age of
50-150Myr. Using our re-evaluated age of the primary and the Gaia
parallax, along with the photometry and spectrum for W1243, we find
Teff=1303±31K, log g=4.3±0.17cm/s2, and a mass of 15±5MJup. We
find a physical separation of ∼1662au and a mass ratio of ∼0.01 for
this system. Placing it in the context of the diverse collection of
binary stars, brown dwarfs, and planetary companions, the BD+60 1417
system falls in a sparsely sampled area where the formation pathway is
difficult to assess.
Description:
On the night of 2021 January 10 (UT) we observed the primary
BD+60 1417 using the Kast optical spectrograph on the Shane 3m
telescope at Lick observatory. We observed the system using the 2"
slit with one 60s exposure in the red channel (6300-9000Å).
We observed the secondary CWISER J124332.12+600126.2 (W1243) on two
separate nights using the SpeX spectrograph on NASA's Infrared
Telescope Facility (IRTF) telescope. The first data were taken on the
night of 2021 January 4 (UT) under good conditions with minimal cloud
coverage, and the second set on 2021 January 31 (UT) under varying
cloud conditions. The data were taken in prism mode using the 0.8"
slit to achieve a resolving power of ∼100-500 over the 0.8-2.5um
coverage.
Objects:
---------------------------------------------------------------
RA (ICRS) DE Designation(s)
---------------------------------------------------------------
12 43 33.27 +60 00 52.7 BD+60 1417 = TYC 4162-626-1
12 43 32.10 +60 01 26.5 W1243 = CWISER J124332.12+600126.2
---------------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig2.dat 33 811 The SpeX Prism spectrum for CWISER J124332.12+600126.2
fig6.dat 38 2682 The Kast optical spectrum of BD+60 1417
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See also:
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/365 : The CatWISE2020 catalog (updated version 28-Jan-2021) (Marocco+, 2021)
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
J/other/ARA+A/43.195 : L and T dwarf stars (Kirkpatrick, 2005)
J/ApJ/670/1367 : Gemini Deep Planet Survey (Lafreniere+, 2007)
J/ApJ/676/1281 : L and T dwarfs in 2MASS/SDSS (Metchev+, 2008)
J/ApJS/181/62 : Survey of young solar analogs (Metchev+, 2009)
J/A+A/517/A76 : Near-IR spectrum of 2M1207b (Patience+, 2010)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/ApJ/752/56 : BDKP. III. Plx for 70 ultracool dwarfs (Faherty+, 2012)
J/ApJ/777/160 : NIR survey for planets around MG stars (Biller+, 2013)
J/ApJ/794/159 : Statistical analysis of exoplanet surveys (Brandt+, 2014)
J/ApJ/788/81 : BANYAN III. RVel and rotation of low-mass stars (Malo+, 2014)
J/MNRAS/454/593 : Young moving groups in solar neighbourhood (Bell+, 2015)
J/ApJ/810/158 : M,L,T dwarfs fundamental param. and SEDs (Filippazzo+, 2015)
J/ApJS/219/33 : BANYAN. VII. Candidate YMG members from BASS (Gagne+, 2015)
J/ApJ/798/122 : Abundances from SEGUE Stellar Param. Pipeline (Miller+, 2015)
J/ApJS/225/10 : Kinematic analysis of M7-L8 dwarfs (Faherty+, 2016)
J/ApJ/833/96 : Hawaii IR parallax program. II. Ultracool dwarfs (Liu+, 2016)
J/AJ/152/113 : Pleiades members with K2 LCs. I. Periods (Rebull+, 2016)
J/ApJ/818/176 : HST/WFC3 NIR photometry of 2M1207b (Zhou+, 2016)
J/A+A/587/A57 : HR 8799e and HR 8799d spectra (Zurlo+, 2016)
J/ApJ/842/83 : Praesepe members rot. periods from K2 LCs (Douglas+, 2017)
J/ApJ/838/73 : BD surface gravities with Keck/NIRSPEC (Martin , 2017)
J/AJ/154/245 : Survey of Spitzer-detected debris disks (Meshkat+, 2017)
J/AJ/153/101 : Pleiades members stellar properties (Somers+, 2017)
J/A+A/603/A3 : VLT/NaCo Large prog. IV. Statistical analysis (Vigan+, 2017)
J/AJ/155/34 : Analysis of the NIR sp. of neighboring L dwarfs (Cruz+, 2018)
J/ApJ/862/138 : BANYAN. XIII. Nearby young assoc. with GaiaDR2 (Gagne+, 2018)
J/ApJ/856/23 : BANYAN. XI. The BANYAN Σ algorithm (Gagne+, 2018)
J/AJ/155/226 : Gemini Planet Imager sp. of HR 8799 c/d/e (Greenbaum+, 2018)
J/AJ/156/102 : TESS Input Catalog and Candidate Target List (Stassun+, 2018)
J/AJ/158/13 : The first 300 stars observed by the GPIES (Nielsen+, 2019)
J/MNRAS/485/4423 : The Gaia ultracool dwarf sample (Smart+, 2019)
J/AJ/159/257 : Hawaii IR plx program. IV. L0-T8 BDs with UKIRT (Best+, 2020)
J/AJ/159/63 : New AO obs. of exoplanets & BD companions (Bowler+, 2020)
J/ApJ/889/176 : Very low-mass binaries with Gaia DR2 data (Faherty+, 2020)
J/ApJ/903/96 : The µTau Association (MUTA) (Gagne+, 2020)
J/ApJ/899/123 : Spitzer follow up of 95 brown dwarfs (Meisner+, 2020)
J/ApJ/893/67 : Smoothed amplitudes from Kepler, K2 & TESS (Morris, 2020)
J/ApJ/898/77 : NIR spectra of 2 extreme T-type subdwarfs (Schneider+, 2020)
J/AJ/160/38 : Spitzer variability detections of 79 BDs (Vos+, 2020)
J/A+A/649/A6 : Gaia Cat. of Nearby Stars - GCNS (Gaia collaboration, 2021)
J/ApJS/253/7 : A full-sky census of BDs within 20pc (Kirkpatrick+, 2021)
Byte-by-byte Description of file: fig2.dat
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Bytes Format Units Label Explanations
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1- 8 F8.6 um lambda Wavelength
10- 21 E12.5 cW/m2/nm Flux Flux in erg/s/cm2/Å
23- 33 E11.5 cW/m2/nm e_Flux Uncertainty in Flux
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Byte-by-byte Description of file: fig6.dat
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Bytes Format Units Label Explanations
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1- 9 F9.4 0.1nm lambda Wavelength; Angstroms
11- 24 E14.7 cW/m2/nm Flux Flux in erg/s/cm2/Å
26- 38 E13.7 cW/m2/nm e_Flux Uncertainty in Flux
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 16-May-2023