Central Bureau for Astronomical Telegrams
IAUC 3431: Occn OF AGK3 +0 1022 BY (3); THE DOUBLE QUASAR Q0957+561; Corrs
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Read IAUC 3432
Circular No. 3431
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
OCCULTATION OF AGK3 +0 1022 BY (3) JUNO
R. Elliott, University of Wisconsin, reports a positive
photoelectric observation of this event (BAA Handbook for 1979, p. 26)
as follows: disappearance, Dec. 11d09h00m21s +/- 1s UT; reappearance,
11d09h01m28s; Long. = +91o29'57".66, Lat. = +44o47'44".42, h = 268 m. M.
Bicay and S. Donnell assisted. Conditions were gpod but somewhat
hazy. No secondary events were detected during 8h57m-9h03m UT.
W. Osborn, Central Michigan University, also reports a positive
photoelectric observation: disappearance, Dec. 11d08h58m31s +/-
2s UT; reappearance, 11d08h59m49s; Long. = +84o46'28".3, Lat. = +43o35'15".3,
h = 258 m. Conditions were quite good but with scattered clouds.
The magnitude drop was ~ 0.7. A secondary event lasting 2s at Dec.
11d09h01m37s UT is believed to be instrumental in origin.
THE DOUBLE QUASAR Q0957+561
J. E. Gunn, J. Kristian, J. B. Oke, J. A. Westphal and P. J.
Young, Hale Observatories, report further evidence that this object
is formed by a gravitational lens. The intervening galaxy is the
brightest member of a rich cluster, seen on a deep red CCD exposure
taken at the 5-m telescope. The galaxy has a total magnitude of
18.5 and is centered 0".75 north of the southern QSO component,
Q0957+561B. Multichannel spectrophotometry of the two QSO images
shows a galaxy component in the spectrum of Q0957+561B, with a
redshift of 0.4. Detailed calculations of the gravitational-lens
effect, based on models for both the galaxy and the cluster, lead to
a prediction that the southern QSO image, Q0957+561B, may itself be
double, with a separation below the resolution of existing data.
Some models predict a separation of 0".2 and a brightness ratio of ~
1.6, with the brighter component to the south. Other observers
using higher-resolution techniques (VLBI, speckle interferometry,
etc.) are urged to examine their data for the possible detection of
this effect.
CORRIGENDA
IAUC 3416, PKS 2155 and Cygnus X-2. Lines 4-3 from the foot should
read: "539), the 150-nm flux was ~ 10**-16 J m**-2 s**-1 nm**-1, while
on Oct. 15.7 UT, at phase 0.6, it was hardly detectable over the
background. Several".
IAUC 3429, 1979 VA, line 19. For 0.4-cm read 0.4-m.
1979 December 14 (3431) Brian G. Marsden
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