Electronic Telegram No. 5735
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


(307616) 2003 QW_90
     B. Proudfoot, Florida Space Institute; W. Grundy, Northern Arizona 
University; D. Ragozzine, Brigham Young University; B. Holler, Space Telescope 
Science Institute; and F. L. Rommel and E. Fernandez-Valenzuela, Florida Space 
Institute, report that the transneptunian object (307616) is a tight, 
approximately equal-sized binary where the secondary is 0.32 +/- 0.14 mag 
fainter than the primary.  The binary was discovered in four 350-s Hubble 
Space Telescope exposures taken with the WFC3/UVIS camera (+ F350LP filter) on 
2026 Sept. 5.  At the time of the HST imaging, the resolved components were 
separated by 0".060 +/- 0".001 in p.a. 136 +/- 1 deg.  At the time of the 
first image (Sept. 5.4544 UT), the primary was located at R.A. = 1h42m35.66s,
Decl. = +12d31'24".6 (equinox J2000.0). 


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                         (C) Copyright 2026 CBAT
2026 September 12                (CBET 5735)              Daniel W. E. Green