Central Bureau for Astronomical Telegrams
IAUC 3511: H 2252-035; TYCHO'S SN
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Circular No. 3511
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM Telephone 617-864-5758
H 2252-035
B. Warner, University of Cape Town, reports: "Photometric
observations on Aug. 29-30 of the optical candidate for the x-ray
source H 2252-035 (Griffiths et al., preprint) show rapid variability.
Flickering on time scales 50-200 s and amplitudes up to 15
percent are superimposed on a regular 14.2-min oscillation whose
amplitude is variable (reaching 40 percent). Occasional extended
trains of quasi-periodic oscillations with periods near 100 s are
present. The similarity of the light curve to those of AM CVn
(1972, M.N. 159, 101) and WZ Sge (1972, M.N. 156, 297) suggests
that H 2252-035 is a cataclysmic variable with orbital period 14m."
J. Patterson, Harvard-Smithsonian Center for Astrophysics; and
C. Price, University of Michigan, write: "Photometry of the optical
counterpart of this HEAO-1 x-ray source (Griffiths et al., preprint)
during July at McGraw-Hill and McDonald Observatories reveals the
existence of two strictly periodic modulations in the (unfiltered)
light curve. A smooth variation of ~ 25 percent occurs with a period
of 3h.588 +/- 0h.002; superimposed on this is a sinusoidal variation
of ~ 10 percent amplitude with period 14m.3117 +/- 0m.0003. Average
magnitudes are V = 13.4, B-V = -0.06, U-B = -0.88. Spectroscopy at
McGraw-Hill Observatory shows broad lines (FWHM = 2.0 nm at H-beta) of
H and He II on a blue continuum. The He II 468.6 nm and H-beta lines
move with K = 145 km/s and P = 3h.59; this is likely to be the
orbital period of the underlying cataclysmic binary. Synchronous
spectrophotometry at the 14-min period yields typical upper limits
of K < 50 km/s for radial velocity variations at this period. The
large amplitude and high stability of the 14-min oscillation suggest
an origin in the rotation of an accreting, magnetized compact
star. The Lx/Lopt ratio suggests that it is a white dwarf and is
related to AM Her. H. Bond informs us that this object is identical
to HK 38 4-7, a star extensively observed in 1977-78 by Preston,
Lanning and Mochnacki, who independently derived the 3.6-hour
orbital period at that time."
TYCHO'S SUPERNOVA
C. Morbey and S. van den Bergh, Dominion Astrophysical Observatory,
telex that 7 red plates of Tycho's supernova remnant obtained
with the Hale 5-m telescope were digitally stacked to yield a
composite which shows no stellar image at the position of the reported
radio source (cf. IAUC 3502); the limiting magnitude was R = 23.2.
1980 September 8 (3511) Daniel W. E. Green
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