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New Asteroids!
Updated 24 Mar 1998
Latest Finds!
1997 XF11
E. F. Helin,
Jet Propulsion Laboratory, reports that K. J. Lawrence
has located prediscovery observations
of this object in 1990 on films
taken by Helin, Lawrence and B. Roman
in the course of the Planet-Crossing
Asteroid Survey with the 0.46-m Schmidt
telescope at
Palomar:
1990
UT
R.A. (2000) Decl.
B
Mar.
22.44427 13 15 16.50 -12 54 21.2
17.3
22.47674 13 15 13.91 -12 54 04.3
23.44062 13 14 00.86 -12 45 47.4
23.46632 13 13 58.73 -12 45
34.4
The following
improved orbital elements have been computed by
G. V. Williams, Harvard-Smithsonian Center
for Astrophysics, from 99
observations at the 1990 and 1997-1998
apparitions, the mean
residual being
0".58:
Epoch = 1997 Dec. 18.0 TT
T = 1997 July
1.1954 TT Peri. =
102.4645
e =
0.483775
Node = 214.1319 2000.0
q = 0.744247
AU
Incl. = 4.0948
a = 1.441710 AU n = 0.5693602 P
= 1.731
years
1998 TT R. A.
(2000) Decl. Delta
r Elong. Phase V
Mar.
8 6 15.92 +17
56.7 1.557 2.070 106.5
27.4 20.8
13 6 19.04 +18
08.0 1.629 2.080 102.3
27.8 20.9
18 6 22.81 +18
18.0 1.701 2.089
98.2 28.1 21.0
23 6 27.18 +18
26.5 1.773 2.098
94.3 28.3 21.1
28 6 32.08 +18
33.4 1.846 2.105
90.5 28.3 21.2
Apr.
2 6 37.46 +18
38.7 1.917 2.112
86.8 28.2 21.3
7 6 43.26 +18
42.1 1.988 2.118
83.3 28.0
21.4
This new computation
shows that the encounter with the earth in
2028 will occur on Oct. 26.3 UT, the
miss distance then being 0.0064 AU.
A computation from the 60-day-arc orbit
on MPC 31283 indicated a comparable
distance (0.0055 AU). With regard
to the remarks on IAUC 6837, it should
be noted that, from the 88-day arc of
data then available, several
independent authorities gave comparable
nominal miss distances for 2028
Oct. 26: D. K. Yeomans and P. Chodas,
Jet Propulsion Laboratory, derived
0.00058 AU; K. Muinonen, University of
Helsinki, 0.00033 AU; and E. Bowell,
Lowell Observatory, 0.00023 AU.
The new computation shows that there were
also approaches to 0.032 AU in 1971 and
to 0.015 AU in 1957.