Electronic Telegram No. 4242
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
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e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
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Prepared using the Tamkin Foundation Computer Network


COMET C/2016 B1 (NEOWISE)
     J. Bauer, Jet Propulsion Laboratory, forwards a report from Emily Kramer
of the discovery of another comet found on infrared images taken with the
Near-Earth Object Wide-field Infrared Survey Explorer (or NEOWISE; formerly
the WISE earth-orbiting satellite; cf. CBET 4225).  The discovery observations
from Jan. 17-18 are tabulated below, in which the listed optical-wavelength
magnitude was roughly estimated based on past WISE and NEOWISE cometary
observations.  Bauer adds that follow-up observations were obtained by J.
Masiero, A. Shugart, L. Magill, A. Lopez, and M. Gomez with the Gemini 8.0-m
reflector (+ GMOS) at Cerro Pachon, Chile, on Jan. 22.3 UT that show an
obvious coma of red mag 18.8-20.0 with a faint tail extending to the east-
northeast.

     2016 UT             R.A. (2000) Decl.       Mag.
     Jan. 17.87360   12 23 55.71   -46 39 51.4    19
          17.93918   12 23 57.22   -46 40 15.5
          18.00475   12 23 58.66   -46 40 40.0
          18.26694   12 24 04.79   -46 42 17.8
          18.46368   12 24 09.27   -46 43 32.0
          18.59471   12 24 12.32   -46 44 18.1
          18.66029   12 24 13.80   -46 44 39.9
          18.85703   12 24 18.19   -46 45 51.8
          18.98806   12 24 21.35   -46 46 43.6
          18.98819   12 24 21.42   -46 46 40.2

After the object was posted on the Minor Planet Center's PCCP webpage, R.
Holmes (Ashmore, IL, USA) writes that CCD images taken by T. Linder and
himself with an 0.61-m f/6.5 Dall-Kirkham astrograph at Cerro Tololo on Jan.
21.34-21.35 UT show a 10" coma without an obvious cometary tail on five
stacked 20-s exposures; the magnitude (stated as V) was measured as 19.0-19.7.
     The available astrometry (spanning Jan. 17-22), the following preliminary
parabolic orbital elements by G. V. Williams, and an ephemeris appear on MPEC
2016-B63.

     T = 2016 Sept.19.6636 TT         Peri. = 338.0745
                                      Node  = 239.4108  2000.0
     q = 4.272297 AU                  Incl. =  47.4651


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2016 CBAT
2016 January 23                  (CBET 4242)              Daniel W. E. Green