Central Bureau for Astronomical Telegrams
IAUC 3414: SATURN'S RINGS; Prob. N IN Sgr; SS 433; TIME ADJUSTMENT ON 1979 Dec. 31
The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).
Read IAUC 3415
Circular No. 3414
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
SATURN'S RINGS
H. J. Reitsema, Lunar and Planetary Laboratory, communicates:
"Observers of the edgewise Saturnian rings are urged to obtain
absolute flux calibrations for ring thickness measurements. For
observations made with spectral response functions other than the
standard UBVRI system measurements of stars with spectrophotometric
calibration are necessary. Stars that are suitable for this (e.g.,
Breger 1976, Ap. J. Suppl. 32, 7) are alpha Leo (HD 87901) and 60 Leo
(HD 95608). The nominal time of passage of the earth through the
ring plane is 1979 Oct. 27.1 +/- 0.2 UT. Observations should extend
for a period of several days before and after the crossing."
PROBABLE NOVA IN SAGITTARIUS
E. P. Belserene, Maria Mitchell Observatory, reports that the
object mentioned on IAUC 3411 is visible at mpg = 12.5-13.6 on
plates obtained during 1978 June 30-Oct. 3.
SS 433
E. M. Leibowitz, T. Mazeh and A. Sternberg, Wise Observatory,
report: "Photometry of SS 433 in the V and B bands was performed
with the Wise Observatory's 1-m telescope on nine nights during
July 23-Sept. 17. Erratic fluctuations up to 0.1 mag on a timescale
of an hour were observed in both colors. The nightly average
intensity of the star was once found to increase by 0.4 mag in both
colors much as described by Kemp and Arbabi (IAUC 3391); this
change took place within one day on Aug. 20-21. Furthermore, on
Aug. 21.8 UT an increase of 0.23 mag in V and 0.33 mag in B was
observed within two hours. These observations suggest a timescale
shorter than one day for optical variations of a few tenths of a
magnitude similar to the infrared variations (Impey, IAUC 3379)."
TIME ADJUSTMENT ON 1979 DECEMBER 31
The Bureau International de l'Heure informs us that a positive
leap second will occur such that the sequence of UTC second markers
will be: 1979 Dec. 31d23h59m59s, 31d23h59m60s, 1980 Jan. 1d00h00m00s.
1979 October 12 (3414) Brian G. Marsden
Read IAUC 3415
Our Web policy. Index to the CBAT/MPC/ICQ pages.
