22P/Kopff (0022P)
TRY AGAIN 2027
Type: Periodic
Perihelion date: 18 March 2022
Perihelion distance (q): 1.6
Aphelion distance (Q) : 5.3
Period (years): 6.4
Eccentricity (e): 0.55
Inclination (i): 4.7
JPL orbit diagram
COBS lightcurve
The comet was discovered at Königstuhl Observatory on Heidelberg, Germany. Kopff
analyzed photographic plates which he exposed on August 20, 1903 against pre-
discovery images of the same region. On August 23, 1903, Kopff concluded it to be a
comet with an estimated apparent magnitude of 11.
On mid-September 1906, the short-period nature of the comet was recognized by a
team headed by Kiel Ebell of the Berkeley Astronomical Department. The comet was
missed when it made a return on November 25, 1912 however on June 25, 1919,
astronomers recovered the comet. The comet was located less than three days from
the predicted position.
Over the next several returns to Earth, none were notable until the 1945 comet’s
return when the comet peaked at magnitude 8.5. The increase in brightness was a
result of Jupiter altering the comet’s orbit between the years of 1939 to 1945. This
change in orbit brought the comet closer to the Sun.
The 1951 return was unique due to the comet being 3 magnitudes fainter than what
was expected when recovered in April 1951. But the comet still reached magnitude
10.5 in October 1951.
A very close pass to Jupiter in 1954 increased the comet’s perihelion distance to 1.52
AU and increased the orbital period to 6.31 years.
On November 30, 1994, Carl W. Hergenrother was able to recover the comet at a
stellar magnitude of 22.8 using the 1.5-m reflector at the Catalina Sky Survey. The
comet reached magnitude 7 during the 1996 perihelion passage. The comet nucleus
is estimated to be 3.0 kilometers in diameter with an albedo of 0.05. The nucleus is
dark because hydrocarbons on the surface have been converted to a dark, tarry like
substance by solar ultraviolet radiation.
Observations (VEMag = visual equivalent magnitude)
Date
10x10 mag
Error
VEmag
Coma '
02-Feb-15
17.43
0.06
16.2
0.2
23-Feb-15
16.93
0.05
16.0
0.3
11-Mar-15
16.19
0.07
13.2
0.2
18-Mar-15
16.29
0.02
14.9
0.3
08-Apr-15
15.55
0.02
13.7
0.4
15-Apr-15
15.59
0.04
13.9
0.4
22-Apr-15
15.75
0.07
14.5
0.3
09-May-15
15.52
0.03
12.7
0.3
16-May-15
15.66
0.02
12.4
0.3
23-May-15
15.58
0.02
13.4
0.3
02-Jun-15
15.54
0.04
12.6
0.2
10-Jun-15
15.65
0.01
13.3
0.6
05-Jul-15
15.35
0.02
12.1
0.4
20-Jul-15
15.31
0.02
12.9
0.6
26-Jul-15
15.39
0.06
12.1
0.3
09-Aug-15
15.36
0.01
11.8
0.3
18-Jan-21
18.3
0.4
07-Feb-21
18.6
0.4
14-Feb-21
18.5
0.4
05-Mar-21
18.1
0.4
12-Mar-21
18.6
0.2
01-Apr-21
17.9
0.4
10-Apr-21
17.7
0.4
16-Apr-21
18.0
0.4
04-May-21
18.0
0.4
24-Aug-22
14.6
1.5
06-Sep-22
15.0
1.1
21-Sep-22
14.7
1.3
30-Sep-22
16.46
0.02
19-Oct-22
15.4
0.9
26-Oct-22
15.2
1.3
13-Nov-22
15.3
1.7