Central Bureau for Astronomical Telegrams
IAUC 5004: MWC 560; 1989c1; V3890 Sgr
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 5005
Circular No. 5004
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505
MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN
MWC 560
S. P. Maran and A. G. Michalitsianos, Laboratory for Astronomy
and Solar Physics, Goddard Space Flight Center, write: "Observations
made on Apr. 29 with the International Ultraviolet Explorer
show that the strong, velocity-variable absorption spectrum seen in
the 120- to 200-nm range, previously observed to be blueshifted
(IAUC 4979) by amounts ranging up to 3500 km/s during Feb. 4-Mar.
29 with respect to the spectrum observed with IUE on 1984 Mar. 14,
has returned to a nominal 'home state' velocity defined by the 1984
observation. In home state, the Al III absorption at 185.4 nm has
a velocity of -530 km/s with respect to rest. The total flux in
the 120- to 320-nm range on Apr. 29, 1.1 x 10E-9 erg cmE-2 sE-1,
was four times brighter than on 1984 Mar. 14. The occurrence of
rapid ultraviolet spectral variations is indicated by two 16-min
exposures, made 172 min apart on Apr. 29, that showed a substantial
decrease in the equivalent widths of several strong absorption
features in the 120-200 nm range during that interval, while the
total flux in that range increased by about 10 percent."
COMET AUSTIN (1989c1)
D. G. Schleicher, Lowell Observatory, reports that further
aperture photometry (cf. IAUC 5001) obtained on May 1.46 UT using
the Lowell 1.07-m telescope yields the following Haser model
production rates: log Q(OH) = 28.75, log Q(CN) = 26.45, log Q(C2) =
26.44, log Q(C3) = 25.12, and log Q(NH) = 26.46; dust production:
log (A f rho) = 3.0.
Total visual magnitude estimates (cf. IAUC 4999): Apr. 25.47
UT, 5.1 (C. S. Morris, near Mt. Wilson, CA, 10x50 binoculars; 3 deg
tail); 27.20, 4.9 (A. Pereira, Linda-a-Velha, Portugal, 9x34
binoculars; 1.4 fan tail in p.a. 270-360 deg, 4 deg narrow tail at p.a.
355 deg); 28.46, 4.8 (J. V. Scotti, Kitt Peak, AZ, naked eye); 29.20,
5.3 (M. Kidger, Izana, Tenerife, Canary Is., 10x50 binoculars);
30.46, 5.0 (C. Spratt, Victoria, BC, 11x80 binoculars); May 1.09,
5.0 (J. D. Shanklin, Cambridge, England, 20x80 binoculars).
V3890 SAGITTARII
Visual magnitude estimates (cf. IAUC 5002): Apr. 28.72 UT, 8.6
(A. Jones, Nelson, N.Z.; assuming SAO 186891 has mv = 8.6); 29.70,
8.6 (Jones); 29.85, 9.1 (A. Pearce, Scarborough, W.A.); May 1.85,
9.4 (Pearce).
1990 May 2 (5004) Daniel W. E. Green
Read IAUC 5005
Our Web policy. Index to the CBAT/MPC/ICQ pages.
