Central Bureau for Astronomical Telegrams
IAUC 6316: HD 3346
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Circular No. 6316
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
Phone 617-495-7244/7440/7444 (for emergency use only)
HD 3346
R. Noyes, S. Korzennik, P. Nisenson, S. Jha, and M.
Krockenberger, Smithsonian Astrophysical Observatory; T. Brown, T.
Kennelly, and C. Rowland, High Altitude Observatory; and S. Horner,
Pennsylvania State University, report the detection of large short-
term radial-velocity variations in the K5 III star HD 3346 = HR 152.
Irregularly spaced observations were made with the Advanced Fiber
Optic Echelle (AFOE) spectrometer at the 1.5-m telescope of the
Whipple Observatory during the last quarters of 1993, 1994, and
1995, with more intensive observations in December 1995 and
February 1996. A long-period radial-velocity variation similar to
that already reported by McClure et al. (1985, PASP 97, 740) is
seen with amplitude of order 500 m/s and period of order 650 days.
This is consistent with a companion to HD 3346 at orbital distance
about 2.5 AU. If the mass of HD 3346 is 5 solar masses, then this
already-reported companion would have projected mass m sin i about
60 Jupiter masses. The AFOE data reveal the presence of shorter-
term radial-velocity variations superimposed on the 650-day
variation. The amplitude of the variations is in the range 150-300
m/s. Near-nightly observations in December 1995 and February 1996
show the variations to be consistent with those produced by a
second orbital companion. The window function of the data would
allow for its period to be near 14, 18, 24, or 40 days. Such a
short period would imply that the second companion's orbit would
have a semimajor axis between 0.2 and 0.4 AU; the amplitude of the
variation implies that (again, if HD 3346 has a mass of 5 solar
masses) this second companion has m sin i about 10 Jupiter masses.
Acoustic pulsations may be an alternative source of the short-term
radial-velocity variations. However, the fundamental period of
acoustic pulsations in giants is expected to be only a few days;
the present data could be explained by acoustic pulsations only if
the star has a mass much lower than suggested by standard stellar-
evolution theory. Spurious signals due to rotation of starspots
appear to be unlikely because of the low reported rotational
velocity for HD 3346. A definitive period for the short-period
radial-velocity variation may be determinable if other
contemporaneous precise radial-velocity observations of this star
exist or can be obtained before the star disappears behind the sun
for this observing season.
(C) Copyright 1996 CBAT
1996 February 16 (6316) Daniel W. E. Green
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