A Caltech Library Service

The First ALLWISE Proper Motion Discovery: WISEA J070720.50+170532.7

Wright, Edward L. and Kirkpatrick, J. Davy and Gelino, Christopher R. and Fajardo-Acosta, Sergio and Mace, Gregory and Eisenhardt, Peter R. and Stern, Daniel and McLean, Ian S. and Skrutskie, M. F. and Oza, Apurva and Nelson, M. J. and Cushing, Michael C. and Reid, I. Neill and Fumagalli, Michele and Burgasser, Adam J. (2014) The First ALLWISE Proper Motion Discovery: WISEA J070720.50+170532.7. Astronomical Journal, 147 (3). Art. No. 61. ISSN 0004-6256. doi:10.1088/0004-6256/147/3/61.

PDF - Published Version
See Usage Policy.

PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


While quality checking a new motion-aware co-addition of all 12.5 months of Wide-field Infrared Survey Explorer (WISE) data, we found that the source WISE J070720.48+170533.0 moved 0".9 in six months. Backtracking this motion allowed us to identify this source as 2MASS J07071961+1705464, with several entries in the USNO B catalog. An astrometric fit to these archival data gives a proper motion of μ = 1793 ± 2 mas yr^(–1) and a parallax of ω = 35 ± 42 mas. Photometry from WISE, 2MASS, and the POSS can be fit reasonably well by a blackbody with T = 3658 K and an angular radius of 4.36 × 10^(–11) radians. No clear evidence of H_2 collision-induced absorption is seen in the near-infrared. An optical spectrum shows broad deep CaH bands at 638 and 690 nm, broad deep Na D at 598.2 nm, and weak or absent TiO, indicating that this source is an ultra-subdwarf M star with a radial velocity v_(rad) ≈ –21 ± 18 km s^(–1) relative to the Sun. Given its apparent magnitude, the distance is about 39 ± 9 pc and the tangential velocity is probably ≈330 km s^(–1), but a more precise parallax is needed to be certain.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Wright, Edward L.0000-0001-5058-1593
Kirkpatrick, J. Davy0000-0003-4269-260X
Fajardo-Acosta, Sergio0000-0001-9309-0102
Mace, Gregory0000-0001-7875-6391
Stern, Daniel0000-0003-2686-9241
Cushing, Michael C.0000-0001-7780-3352
Fumagalli, Michele0000-0001-6676-3842
Burgasser, Adam J.0000-0002-6523-9536
Additional Information:© 2014 American Astronomical Society. Received 2013 October 23; accepted 2013 December 6; published 2014 February 10. We thank the referee, Ralf-Dieter Scholz, for a very fast and useful report pointing out the UCAC and CMC observations. This publication makes use of data products from the Widefield Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. The WISE, 2MASS, and USNO B data were all provided by the Infrared Science Archive at Caltech. The Digitized Sky Survey images were provided by the Space Telescope Science Institute. Support for M.F. was provided by NASA through Hubble Fellowship grant HF-51305.01-A. This research has benefitted from the SpeX Prism Spectral Libraries maintained by Adam Burgasser at Facilities: WISE, FMO:31in/FanCam, Hale (DoubleSpec), ARC (TSpec)
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
NASA Hubble FellowshipHF-51305.01-A
Subject Keywords:brown dwarfs; infrared: stars; solar neighborhood; stars: individual (WISEA J070720.50+170532.7); stars: late-type; stars: low-mass
Issue or Number:3
Record Number:CaltechAUTHORS:20140314-084243626
Persistent URL:
Official Citation:The First ALLWISE Proper Motion Discovery: WISEA J070720.50+170532.7 Edward L. Wright et al. 2014 The Astronomical Journal 147 61
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:44311
Deposited By: Ruth Sustaita
Deposited On:14 Mar 2014 18:40
Last Modified:10 Nov 2021 16:50

Repository Staff Only: item control page