TA e-circular

<title>TA e-circular</title>
<pre>
THE ASTRONOMER Electronic Circular No 497       1991 Mar 19 20.59UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise,  Basingstoke,
Hants, RG22 4PP, England. Telephone:  (0256)471074 Int:+44256471074
Telex: 9312111261 Answerback: TA G                     JANET BOXES:
GMH at UK.AC.CAM.ASTRONOMY.STARLINK or GUYH at UK.AC.SUSSEX.CLUSTER
TELECOM GOLD: 10074:MIK2885                       PRESTEL 256471074
-------------------------------------------------------------------
COMET MRKOS (1991k)
On Mar. 17 Antonin Mrkos, Klet Observatory, reported his discovery
of a rapidly moving object.  Films taken at Palomar by E.Helin et
al. show the object to be somewhat diffuse, and Mrkos later
described the object as diffuse with central condensation.
Available observations:
     1991 UT             R.A. (1950) Decl.        m1    Observer
     Mar. 16.95628   12 44 29.36   - 2 47 07.9   15     Mrkos
          16.97017   12 44 27.13   - 2 48 00.8            "
          17.03753   12 44 16.12   - 2 52 20.0   15       "
          17.04517   12 44 14.79   - 2 52 52.2            "
          17.98406   12 41 43.03   - 3 53 58.3            "
          17.99170   12 41 41.72   - 3 54 28.3            "
          18.02642   12 41 35.98   - 3 56 38.7   15       "
          18.03406   12 41 34.62   - 3 57 07.8            "
          18.24219   12 41 01.86   - 4 10 45.1   14.0   Helin
          18.27500   12 40 56.11   - 4 12 54.9            "
          18.54028   12 40 11.89   - 4 29 53.9   15     McNaught
          18.62014   12 39 59.01   - 4 35 07.3   13     Lowe
          18.88368   12 39 13.86   - 4 52 14.0            "

The following preliminary parabolic orbital elements are from 8
observations Mar. 16-18.  The comet may be of short period.
     T = 1991 Mar. 20.992 ET          Peri. = 181.852
                                      Node  =   1.941   1950.0
     q = 1.55617 AU                   Incl. =  40.651
Ephemeris by Hurst based on a program by N.James:
m = 13.0 + 5.0 log R + 10.0 log r
  Date    R.A. (1950) Dec.     R       r     Elong  Mag.    Motion
          h  m       o  '     (AU)    (AU)     o          "/hr P.A.
1991 Mar
  19.00  12 38.93   -5  0.1   0.571   1.556  166.4  13.7   194  212
  20.00  12 36.13   -6  5.9   0.569   1.556  167.4  13.7   195  213
  21.00  12 33.28   -7 11.9   0.568   1.556  168.3  13.7   196  213
  22.00  12 30.39   -8 17.9   0.567   1.556  169.0  13.7   197  213
  23.00  12 27.47   -9 23.9   0.566   1.556  169.5  13.7   197  213
  24.00  12 24.52  -10 29.7   0.566   1.557  169.6  13.7   197  214
  25.00  12 21.54  -11 35.1   0.566   1.557  169.4  13.7   197  214
  26.00  12 18.54  -12 40.0   0.567   1.558  169.0  13.7   196  214
  27.00  12 15.53  -13 44.3   0.568   1.558  168.3  13.7   194  214
  28.00  12 12.50  -14 47.9   0.570   1.559  167.4  13.7   192  215
  29.00  12  9.48  -15 50.7   0.572   1.560  166.4  13.7   190  215
  30.00  12  6.45  -16 52.4   0.575   1.561  165.2  13.7   188  215
  31.00  12  3.43  -17 53.1   0.578   1.562  163.9  13.7   185  216

V418 CAS
Further to the note on E493, Mike Collins, Sandy, reports that he
has recorded the star on recent patrol photographs (K2415 film):
1991 Mar 13.8UT, 11.4; 14.9, 11.4. The star is probably red and may
therefore be fainter visually. Close monitoring of this latest
maximum is needed to establish whether this is a mira or nova-like
variable,

Guy M Hurst
</pre>