103P/Hartley (0103P)
TRY AGAIN 2029
Type: Periodic
Perihelion date: 12 October 2023
Perihelion distance (q): 1.1
Aphelion distance (Q) : 5.9
Period (years): 6.5
Eccentricity (e): 0.69
Inclination (i): 13.6
JPL orbit diagram
COBS lightcurve
Periodic comet 103P/Hartley 2 is classed as a young, dwarf comet, with a nucleus
roughly 2.2 km in diameter that rotates once every 18.1 hours. It belongs to the
Jupiter family of comets (comets with periods less than 20 years).
The discovery plate was exposed on 15 March 1986 and, after it was developed,
Malcolm Hartley (U. K. Schmidt Telescope Unit, Siding Spring Observatory, New
South Wales, Australia) noted the diffuse trail of a comet. He estimated the
magnitude as 17-18 and added that a faint tail was evident. Further photographic
plates were exposed on 17 and 20 March, whereupon Hartley annnounced his
discovery to the Central Bureau for Astronomical Telegrams.
During the early decades of the 20th century, the orbital period had been 9.3 years. A
close approach to Jupiter in August 1947 (0.22 AU) reduced the period to 7.9 years,
while another close approach during April 1971 (0.09 AU) reduced the period to 6.1
years.
The comet has been seen at every return since its discovery. The 2010 return was
exceptional, as the comet passed 0.12 AU from Earth on 20 October, and the Deep
Impact space craft passed about 1,000 kilometers from the comet on 4 November.
Observations (VEMag = visual equivalent magnitude)
Date
10x10 mag
Error
VEmag
Coma '
15-Jun-23
18.6
0.4
19-Jun-23
18.3
0.4
17-Aug-23
11.7
5.1
19-Oct-23
8.9
9.8
25-Nov-23
10.0
9.0
18-Dec-23
11.4
6.2
19-Jan-24
13.4
2.6
01-Feb-24
14.2
1.7
08-Feb-24
14.3
2.3
15-Feb-24
14.5
2.3
05-Mar-24
17.6
0.4
14-Mar-24
17.7
0.4
27-Mar-24
18.1
0.4
04-Apr-24
18.1
0.4
02-May-24
19.2
0.4
22-May-24
19.4
0.4