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IAUC 2798: 1975h; N Sct 1975

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                                                  Circular No. 2798
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Cable Address: SATELLITES, NEWYORK
Western Union: RAPID SATELLITE CAMBMASS


COMET KOBAYASHI-BERGER-MILON (1975h)
     Further independent discoveries have been reported.  The
following precise positions have been communicated:

     1975 UT             R. A. (1950) Decl.        m1    Observer
     July  5.28611    21 39 20.48   - 4 02 22.3          McCrosky
           6.32778    21 36 03.09   - 2 27 13.1    7.5   Klemola
           6.46597    21 35 34.19   - 2 13 51.6            "
           8.43403    21 28 02.04   + 1 17 12.4    7.5     "
           9.29167    21 24 10.41   + 3 02 50.6          Schwartz
           9.67535    21 22 18.69   + 3 53 01.6    6     Tomita
           9.67743    21 22 17.95   + 3 53 20.0            "
          10.06318    21 20 20.48   + 4 45 48.0    7     Milet
          10.06726    21 20 19.20   + 4 46 21.4            "

R. E. McCrosky (Harvard College Observatory, Agassiz Station).
   4.2-cm patrol camera.  Comet image trailed.  Measurer: C. Y.
   Shao.
A. R. Klemola (Lick Observatory).  51-cm astrograph.  Correction to
   IAUC 2797: no tail.  Measurer: Klemola.
G. Schwartz (Harvard College Observatory, Agassiz Station).  20-cm
   astrograph.  Comet image trailed.  Poor sky.  Measurer: Shao.
K. Tomita (Tokyo Astronomical Observatory, Dodaira Station).
B. Milet (Nice Observatory).

     The comet is diffuse, with a central condensation, but without
a tail.  The following elements, by Z. Sekanina, satisfy the above
observations within 6".

       T = 1975 Sept. 5.19 ET    Peri. = 117.36
                                 Node  = 295.64   1950.0
       q = 0.4210 AU             Incl. =  80.83

     1975 ET     R. A. (1950) Decl.     Delta     r      m1
     July 11    21 15.18    + 7 02.9    0.373   1.320    6.6
          13    21 01.83    +12 41.4
          15    20 44.35    +19 31.2    0.303   1.250    5.9
          17    20 21.01    +27 32.1
          19    19 49.37    +36 21.7    0.262   1.178    5.3
          21    19 06.40    +45 04.4
          23    18 09.93    +52 20.4    0.264   1.106    5.0
          25    17 02.55    +57 00.6
          27    15 53.91    +58 49.5    0.305   1.033    5.1
          29    14 54.62    +58 29.3

                m1 = 7.5 + 5 log Delta + 10 log r


NOVA SCUTI 1975
     Drs. Y. Andrillat, Ch. Fehrenbach and J. M. Vreux, Haute
Provence Observatory, report a number of features identified in the
spectra taken on 24 June-2 July.  In the region 3600-5000 A (dispersion
20 A/mm): hydrogen emission lines H-beta to H-15, of which H-beta to
H-9 are strong and bounded by an absorption of variable profile
(corresponding expansion velocities on the order of 1000 km/s);
several weak emissions that can be due to O I, O II and N II; a
complex emission of variable intensity near 4650 A; and very narrow
lines of interstellar calcium.  In the region 5670-8750 A (dispersion
230 A/mm): extremely intense H-alpha + [N II]; weak He I lines
(5875, 5678 and 7065 A); [N II] at 5755 A; [O I] and a number of
lines of O I, N I and N II observed in Nova Herculis 1963 and Nova
Deiphini 1967.  In the region 7700-11000 A (dispersion 230 A/mm):
H I (9545 and 10049-10938 A), He I at 10830 A, O I (7772, 8222,
8446, 9265 and 11302 A), N I (8216, 8629, 8680, 9060, 9862, 10113,
13639 and 11329 A), C I (9094, 9406 and 10691 A), S I (8694, 8874,
9213 and 9650 A), Mg II (7877-96 A), and, from 26 June on, [N I]
(10395 and 10404 A); and strong continuum on 24-25 June.

     O. L. Hansen, Cerro Tololo Inter-American Observatory,
obtained the following IR magnitudes on June 22.2556 UT: 6.77 (with
probable error +/- 5%) at 1.57 um (bandpass 0.19 um), 6.19 at 2.27 um
(0.37 um), 5.12 at 3.80 um (0.52 um) and 5.22 (p.e. +/- 20%) at 4.71 um
(0.60 um).  Comparison star: BS 7120.  While the data do not fit a
perfect black body, they are approximately consistent with radiation
from 23000 K.

     The following prediscovery observations have been reported:

                1975    UT     mpv     Observer
                May  17.75     7.8     Nishi
                     22.74     7.5     Harada
                June  9.65     7.4     Osada
                     10.78     7.3     Miyamoto

R. Nishi (Jyoyo).  5.5-cm lens.  Tri-X film, exposure 2 min.
T. Harada (Takefu).  5-cm lens.
K. Osada (Yamaguchi).  5.5-cm lens.
Y. Miyamoto (Kumamoto).  20-cm lens.  Tri-X film, exposure 15 min.

     Dr. D. Hoffleit, Maria Mitchell Observatory, informs us that
a search, by M. Brewster, D. Carmichael, P. Guida, J. Lukas and
M. McGrath, on some 1200 plates (reaching mostly photographic
magnitude 15) taken with the 19-cm Cooke triplet resulted in no
detection of the nova between 1917 and 1974.

     The following selected visual magnitude estimates have been
reported: July 2.22 UT, 9.1 (K. Simmons, Switzerland, Florida);
3.16, 8.5 (Simmons); 4.13, 9.3 (D. di Cicco, Waltham, Massachusetts);
4.20, 9.4 (Simmons); 5.12, 9.3 (di Cicco); 6.25, 8.8 (C.
Sherrod, North Little Rock, Arkansas); 7.25, 8.7 (Sherrod).


1975 July 11                   (2798)              Zdenek Sekanina

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