J/ApJ/943/L16 Keck/NIRES sp. of CWISE J050626.96+073842.4 (Schneider+, 2023)
Redder than Red: Discovery of an Exceptionally Red L/T Transition Dwarf.
Schneider A.C., Burgasser A.J., Bruursema J., Munn J.A., Vrba F.J.,
Caselden D., Kabatnik M., Rothermich A., Sainio A., Bickle T.P.,
Dahm S.E., Meisner A.M., Kirkpatrick J.D., Suarez G., Gagne J.,
Faherty J.K., Vos J.M., Kuchner M.J., Williams S.J., Gagliuffi D.B.,
Aganze C., Hsu C.-C., Theissen C., Cushing M.C., Marocco F., Casewell S.,
(The Backyard Worlds: Planet 9 Collaboration)
<Astrophys. J., 943, L16 (2023)>
=2023ApJ...943L..16S 2023ApJ...943L..16S
ADC_Keywords: Stars, brown dwarf; Spectra, infrared
Keywords: Brown dwarfs ; L dwarfs ; T dwarfs
Abstract:
We present the discovery of CWISE J050626.96+073842.4
(CWISEJ0506+0738), an L/T transition dwarf with extremely red
near-infrared colors discovered through the Backyard Worlds: Planet 9
citizen science project. Photometry from UKIRT and CatWISE give a
(J-K)MKO color of 2.97±0.03mag and a JMKO-W2 color of
4.93±0.02mag, making CWISE J0506+0738 the reddest known
free-floating L/T dwarf in both colors. We confirm the extremely red
nature of CWISE J0506+0738 using Keck/NIRES near-infrared spectroscopy
and establish that it is a low-gravity, late-type L/T transition
dwarf. The spectrum of CWISE J0506+0738 shows possible signatures of
CH4 absorption in its atmosphere, suggesting a colder effective
temperature than other known, young, red L dwarfs. We assign a
preliminary spectral type for this source of L8γ-T0γ. We
tentatively find that CWISE J0506+0738 is variable at 3-5µm based
on multiepoch WISE photometry. Proper motions derived from follow-up
UKIRT observations combined with a radial velocity from our Keck/NIRES
spectrum and a photometric distance estimate indicate a strong
membership probability in the β Pic moving group. A future
parallax measurement will help to establish a more definitive moving
group membership for this unusual object.
Description:
In an effort to refine the astrometry and photometry of
CWISE_J050626.96+073842.4, we observed it with the JMKO filter on
the infrared Wide-Field Camera (WFCAM) on UKIRT on 2022 September 20.
See Section 3.1.
CWISE J0506+0738 was observed with the Near-Infrared Echellette
Spectrometer (NIRES) mounted on the Keck II telescope on UT
2022-Jan-19. NIRES provides a resolution R∼2700 over five
cross-dispersed orders spanning a wavelength range of 0.9-2.45um.
CWISE J0506+0738 was observed in four 250s exposures nodded in an ABBA
pattern along the slit, which was aligned with the parallactic angle,
for a total on-source integration time of 1000s.
See Section 3.2.
Objects:
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RA (ICRS) DE Designation(s)
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05 06 26.93 +07 38 43.5 CWISE J050626.96+073842.4 = CWISE J050626.96+073842.4
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig2.dat 29 6131 The Keck/NIRES spectrum of CWISE J0506+0738
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See also:
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
II/367 : The VISTA Hemisphere Survey (VHS) catalog DR5 (McMahon+, 2020)
II/365 : The CatWISE2020 catalog (updated version 28-Jan-2021) (Marocco+, 2021)
J/other/ARA+A/43.195 : L and T dwarf stars (Kirkpatrick, 2005)
J/ApJ/637/1067 : NIR spectral classification of T dwarfs (Burgasser+, 2006)
J/AJ/132/891 : Binaries among nearby L dwarfs (Reid+, 2006)
J/AJ/134/1162 : 11 new T dwarfs in 2MASS (Looper+, 2007)
J/ApJ/689/1295 : Lithium test implications for BDs (Kirkpatrick+, 2008)
J/ApJ/676/1281 : L and T dwarfs in 2MASS/SDSS (Metchev+, 2008)
J/ApJ/723/684 : NIRSPEC ultracool dwarf RVel survey (Blake+, 2010)
J/ApJS/190/100 : NIR proper motion survey using 2MASS (Kirkpatrick+, 2010)
J/A+A/517/A76 : Near-IR spectrum of 2M1207b (Patience+, 2010)
J/ApJ/743/156 : NEOWISE obs. of NEOs: preliminary results (Mainzer+, 2011)
J/ApJS/201/19 : Hawaii Infrared Parallax Program. I. (Dupuy+, 2012)
J/ApJS/205/6 : T dwarf population revealed by WISE (Mace+, 2013)
J/PASP/125/809 : New nearby M, L, and T dwarfs (Thompson+, 2013)
J/ApJ/792/30 : NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)
J/A+A/564/A55 : 1.1-2.4um sp. of 7 young M and L dwarfs (Manjavacas+, 2014)
J/AJ/147/20 : Spectroscopy of 447 nearby M dwarfs (Newton+, 2014)
J/AJ/147/34 : SpeX library of L-type dwarfs (Schneider+, 2014)
J/MNRAS/454/593 : Young moving groups in solar neighbourhood (Bell+, 2015)
J/ApJ/814/118 : L/T transition dwarfs with PS1 & WISE. II. (Best+, 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/814/65 : Jupiter HST light curves (Karalidi+, 2015)
J/other/Sci/350.64 : 51 Eri b near-infrared spectrum (Macintosh+, 2015)
J/ApJS/225/10 : Kinematic analysis of M7-L8 dwarfs (Faherty+, 2016)
J/ApJ/833/96 : Hawaii infrared parallax program. II. (Liu+, 2016)
J/ApJ/817/112 : NEOWISE/AllWISE high PM objects (Schneider+, 2016)
J/AJ/153/95 : Catalog of Suspected Nearby Young Stars (Riedel+, 2017)
J/AJ/154/69 : ACRONYM II. β Pictoris Moving Group (Shkolnik+, 2017)
J/AJ/155/34 : The NIR spectra of neighboring L dwarfs (Cruz+, 2018)
J/ApJ/856/23 : BANYAN. XI. The BANYAN Σ algorithm (Gagne+, 2018)
J/AJ/159/257 : Hawaii IR parallax program. IV. L0-T8 BDs (Best+, 2020)
J/A+A/642/A179 : beta Pic moving group RV of 81 stars (Miret-Roig+, 2020)
J/AJ/160/38 : Spitzer variability detections of 79 BDs (Vos+, 2020)
J/ApJ/891/171 : COCONUTS. I. Sp. of a WD & T4 comoving syst. (Zhang+, 2020)
J/AJ/161/42 : Volume-limited sample of cool dwarfs. I. (Best+, 2021)
J/ApJ/923/48 : An L dwarf co-moving BD+60 1417 (Faherty+, 2021)
J/ApJS/257/45 : BDKP. V. Radial & rot. vel. of M, L, T dwarfs (Hsu+, 2021)
J/ApJS/253/7 : A full-sky census of BDs within 20pc (Kirkpatrick+, 2021)
J/ApJ/934/178 : L/T transition BDs from NIR SpeX spectra (Ashraf+, 2022)
J/AJ/163/288 : Astrometry for ε Indi B (Chen+, 2022)
J/MNRAS/513/5701 : Silicate clouds in ultracool dwarfs (Suarez+, 2022)
J/AJ/164/239 : IR LC of VHS1256-1257b in 2018 & 2020 epochs (Zhou+, 2022)
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 [0.96/2.5] Wavelength
10- 19 E10.3 cW/m2/nm Flux [-1.8e-16/1.5e-16] Flux;
erg/s/cm2/Angstrom
21- 29 E9.3 cW/m2/nm e_Flux [8.7e-20/4.4e-17] Uncertainty in Flux
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 13-Jan-2025