Central Bureau for Astronomical Telegrams
IAUC 2798: 1975h; N Sct 1975
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Read IAUC 2799
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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