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IAUC 4551: T Pyx; PKS 0823-22; KR Aur; 1988a; NEPTUNE II (NEREID)

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IAUC number

                                                  Circular No. 4551
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM    Telephone 617-495-7244/7440/7444

     E. Schweitzer, AFOEV, Strasbourg, reports that M. Verdenet,
Bourbon-Lancy, France, has observed a rise in brightness of this
recurrent nova to mv = 12.8 on Feb. 21.93 UT.

PKS 0823-22
     E. G. Tanzi, CNR, Milan; P. Bouchet, European Southern
Observatory, La Silla; R. Falomo, Padua; and L. Maraschi and A. Treves,
University of Milan, telex:  "The BL-Lac object PKS 0823-22 was
observed at optical (ESO 1.52-m telescope + CCD spectrograph) and
infrared (ESO 2.2-m telescope + InSb photometer) frequencies on Jan.
7.4 and 8.4 UT, and found to be in its brightest state ever recorded:
V = 15.7, K = 12.0.  An absorption doublet was apparent at
534.0 and 535.4 (+/- 0.1) nm, with equivalent widths 0.23 and 0.12
nm.  Identification with Mg II (279.6, 280.3 nm) yields z >/= 0.910.
For A(V) = 0.6 (as derived from H I columnar density), M(abs) </=
-29.1, placing the object among the most luminous of its class (cf.
Veron-Cetty and Veron 1987, ESO Scientific Report No. 5)."

     R. Monella, Covo, Italy, notes that this object has brightened
rapidly, as indicated by the following visual magnitude estimates:
Feb. 13.910 UT, 15.0; 15.886, 15.0; 16.899, 14.9; 19.890, 13.7;
20.910, 13.6.  E. Waagen, AAVSO, remarks that no known similar
rapid increase in brightness has occurred since at least 1983.

     Total visual magnitude estimates (L = reflector):  Feb. 7.09
UT, 8.6 (R. Keen, Mt. Thorodin, CO, 0.32-m L); 9.75, 8.5 (A.
Boattini, Florence, Italy, 0.33-m L); 13.13, 8.3 (C. S. Morris,
Whitaker Peak, CA, 20x80 binoculars); 15.08, 8.0 (Keen, 0.15-m L);
22.01, 8.3 (G. R. Chester, Rixeyville, VA, 0.14-m L).

     Corrigendum.  The number 3822 +/- 700, given at the end of the
item on IAUC 4542, refers not to the Neptune/Triton mass ratio, but
to 1000/J2, where J2 is the effective dipole form factor due to
both the oblateness of Neptune and the presence of Triton.

1988 February 22               (4551)            Daniel W. E. Green

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