Central Bureau for Astronomical Telegrams
IAUC 2257: N Cyg 1970; VY CMa; P/WOLF-HARRINGTON
The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).
Read IAUC 2258
Circular No. 2257
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
NOVA CYGNI 1970
F. Ciatti, A. Mammano and L. Rosino, Asiago Astrophysical
Observatory, write: "Slit spectra (45 A/mm at H-gamma) obtained on June 12
and objective prism spectra (450 A/mm at H-gamma) obtained on June 11
and 12 show wide Balmer emission from H-alpha to H-zeta, emission bands of
Fe II and N II, [N II] 5755 A fairly strong and a wide blend at
4640 A. Weak emissions of [O I] at 6364, 6300 and 5577 A are doubtful.
H-alpha and H-beta show some structure; [N II] 5755 A has a slightly
saddle-type profile. Absorptions are still visible at the blue end
of some H and Fe II emission bands. The velocity of expansion of
the shells ejected by the nova, derived by the halfwidths of the
strongest emissions, is about 1075 km/s. The star, which very
likely has dropped from 3 to 3.5 magnitudes below maximum, has
reached the "phase 4640" that shortly precedes the nebular stage.
Comparisons with plates of the same field, obtained in 1969 with
the two Schmidt telescopes at Asiago, fail to show any trace of the
nova brighter than B = 18 or any trace of emission. On the Palomar
prints the prenova could be identified with the north component of
a faint double star, photographic magnitude about 19, but the
identification for the moment remains doubtful."
Dorrit Hoffleit and Linda Lucignani at the Maria Mitchell
Observatory have made the following observations on available plates
taken with the 19-cm (7.5-inch) Cooke triplet:
JD mpg JD mpg JD mpg JD mpg
2425070 [14.4 2430634 [14 2430702 [16 2439328 [15.9
25128 [14.5 30640 [14.5 30899 [15.9 39329 [16.0
25144 [14.5 30663 [14.5 30907 [16 39345 [15
25147 [14.5 30668 [14.5 30965 [15.5 39382 [16.2
25159 [15.0 30698 [16.0 32798 [16 40456 [16.0
25454 [14.4 30699 [15.9 39323 [15 40735 9.9
25823 [14.4 30700 [15.9 39324 [15.9 40736 10.1
VY CANIS MAJORIS
L. J. Robinson, Sky and Telescope, communicates: "VY CMa (R.A. =
7h20m.9, Decl. = -25o40', equinox 1950.0) has been observed on plates
from the Harvard collection. Extraordinary variations in blue
light have been found. From about JD 2415000 to 2424000 (1900-1925)
the object showed small amplitude variations around magnitude 9, but
between JD 2424000 and 2434000 (1925-1950) minima as deep as 3
magnitudes prevailed. A comprehensive photometric study of VY CMa is
planned in collaboration with J. Ashbrook, Sky and Telescope, and
D. Friedrich, Bamberg Observatory. In view of the astrophysical
importance of this object (cf. Eliasson and Bartlett 1969, Astrophys.
J. 155, L79) we should like to receive visual or photographic
observations, particularly from the years before 1900 and after
1950."
PERIODIC COMET WOLF-HARRINGTON
Dr. G. Sitarski, Institute of Astronomy, Polish Academy of
Sciences, Warsaw, writes: "Three apparitions of this comet were
linked using 81 observations made in 1951-52, 1957-59 and 1964-65.
To represent well all the observations by one system of elements it
was necessary to assume a nongravitational force acting in the
comet's motion. It appears that a secular acceleration in the
motion of the comet exists: the daily change of the daily mean
motion amounts to (+400".9 +/- 12".6) x 10**-8, which yields a change of
about +11".4 in the mean anomaly for one revolution of the comet.
The observations are then satisfied with a mean residual of +/- 1".98.
Perturbations by the planets Mercury to Neptune were included."
T = 1971 Sept. 1.18364 ET Epoch = 1971 Sept. 6.0 ET
Peri. = 187.01460 e = 0.53677417
Node = 254.20084 1950.0 a = 3.5010705 AU
Incl. = 18.43424 n = 0.15045367
q = 1.62178630 AU P = 6.55090 years
Variation
1970/71 ET R. A. (1950) Decl. Delta r dR.A. dDecl. Mag.
Sept. 1 20 40.07 + 6 05.3 2.465 3.357 -0m60 - 5'5 20.5
11 20 33.69 + 5 17.6 2.482 3.305
21 20 29.12 + 4 24.8 2.521 3.253 -0.56 - 5.1 20.4
Oct. 1 20 26.68 + 3 31.3 2.577 3.200
11 20 26.49 + 2 41.0 2.646 3.147 -0.50 - 4.6 20.4
21 20 28.56 + 1 57.0 2.723 3.092
31 20 32.77 + 1 21.5 2.804 3.038 -0.48 - 4.1 20.4
Nov. 10 20 38.96 + 0 56.2 2.886 2.982
20 20 46.95 + 0 42.1 2.966 2.926 -0.48 - 3.7 20.3
30 20 56.55 + 0 39.6 3.041 2.870
Dec. 10 21 07.58 + 0 49.1 3.108 2.813 -0.49 - 3.5 20.3
20 21 19.86 + 1 10.5 3.167 2.755
30 21 33.26 + 1 43.7 3.215 2.698 -0.53 - 3.3 20.1
Jan. 9 21 47.65 + 2 28.4 3.253 2.640
Mag. = 13.3 + 5 log Delta + 10 log r
1970 June 30 (2257) Brian G. Marsden
Read IAUC 2258
Our Web policy. Index to the CBAT/MPC/ICQ pages.
