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IAUC 5845: N Aql 1993; PSR 1509-58; 1991bl

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IAUC number

                                                  Circular No. 5845
Central Bureau for Astronomical Telegrams
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

     R. J. Ivison, University of Toronto, on behalf of the James
Clerk Maxwell Telescope nova monitoring group, reports the detection
of N Aql 1993:  "The flux densities on Aug. 15.3 UT were 59
+/- 10, 80 +/- 11, and 124 +/- 15 mJy at 1.3, 1.1, and 0.8 mm,
indicating a spectral index of 1.5.  Earlier measurements at 1.1 mm
gave 3-sigma < 16 mJy and 55 +/- 11 mJy during July 1.4 and Aug.
8.4.  The latest data suggest that cm-wave synthesis observations
may soon pay dividends."

PSR 1509-58
     P. A. Caraveo, S. Mereghetti, and G. F. Bignami, Istituto di
Fisica Cosmica del CNR, Milan, communicate:  "Using the New Technology
Telescope at the European Southern Observatory, we have observed
the field of the x-ray/gamma-ray pulsar PSR 1509-58, which
is also the radio pulsar with the highest observed period derivative.
A likely optical counterpart (V = 22.0 +/- 0.2, V-R about
+1.2) is clearly detected at the radio position.  Accurate astrometry
(rms < 0".5) from CCD images obtained on June 22-23 places the
counterpart candidate at R.A. = 15h09m59s.1, Decl. = -58o56'58".2
(equinox 1950.0).  The object's color is dominated by the significant
reddening expected at its low galactic latitude and distance
(about 4 kpc).  If the optical emission is due to PSR 1509-58, it
cannot be of thermal origin, and pulsations at the 150-ms rotation
period should be detectable.  In spite of the much longer spin
period, the implied optical luminosity is comparable to that of the
two other young pulsars, the Crab pulsar and PSR 0540-69, which
have characteristic ages similar to PSR 1509-58 (1600 yr)."

     C. Pollas, Observatoire de la Cote d'Azur, reports his
discovery of an apparent supernova (magnitude V about 17.5) found on
films taken 1991 July 5.93 and 10.92 UT with the OCA Schmidt
telescope. SN 1991bl is located at R.A. = 18h12m37s.28, Decl. =
+68o58'13".9 (equinox 1950.0), or 2".7 west and 0".1 north of the
apparent center of the galaxy (which has a brightness of mpg about
19 and is located at end figures 37s.78, 13".8).  Nothing is
present at this location on the POSS prints or on similar films
obtained on 1991 June 8 and 9 and in 1993.  SN 1991bl does appear at
mag about 20.5 on films taken 1991 Sept. 5.88 and 4.90.

1993 August 17                 (5845)            Daniel W. E. Green

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