| Parameter |
Value |
| Designation |
C/1972 U1 (Kojima) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1973-02-12T06:40:27.632640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:22Z |
| Obs used |
267 |
| NEO |
- |
| M1 |
6.400 |
| K1 |
12.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1973-01-19.0000000 |
| e |
1.00104251 |
| q (au) |
2.147034 |
| a (au) |
-2059.482629 |
| i (deg) |
141.855558 |
| Ω (om, deg) |
43.188266 |
| ω (w, deg) |
334.305975 |
| M (ma, deg) |
-0.000256 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.867 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.867 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.559 |
| k |
0.800 |
| δ90 |
10.000 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
17:29:15.77 |
+02:52:48.9 |
HIP 85601 |
8.52 |
| 2026-06-01 12:00 |
17:29:14.25 |
+02:52:52.0 |
HIP 85601 |
8.65 |
| 2026-06-02 00:00 |
17:29:12.73 |
+02:52:54.9 |
HIP 85601 |
8.80 |
| 2026-06-02 12:00 |
17:29:11.21 |
+02:52:57.8 |
HIP 85601 |
8.96 |
| 2026-06-03 00:00 |
17:29:09.68 |
+02:53:00.6 |
HIP 85601 |
9.14 |
| 2026-06-03 12:00 |
17:29:08.15 |
+02:53:03.3 |
HIP 85601 |
9.33 |
| 2026-06-04 00:00 |
17:29:06.62 |
+02:53:06.0 |
HIP 85601 |
9.53 |
| 2026-06-04 12:00 |
17:29:05.08 |
+02:53:08.5 |
HIP 85601 |
9.75 |
| 2026-06-05 00:00 |
17:29:03.55 |
+02:53:11.0 |
HIP 85601 |
9.98 |
| 2026-06-05 12:00 |
17:29:02.01 |
+02:53:13.4 |
HIP 85601 |
10.22 |
| 2026-06-06 00:00 |
17:29:00.47 |
+02:53:15.7 |
HIP 85601 |
10.47 |
| 2026-06-06 12:00 |
17:28:58.92 |
+02:53:17.9 |
HIP 85601 |
10.72 |
| 2026-06-07 00:00 |
17:28:57.38 |
+02:53:20.0 |
HIP 85601 |
10.99 |
| 2026-06-07 12:00 |
17:28:55.83 |
+02:53:22.1 |
HIP 85601 |
11.27 |
| 2026-06-08 00:00 |
17:28:54.29 |
+02:53:24.1 |
HIP 85601 |
11.55 |
| 2026-06-08 12:00 |
17:28:52.74 |
+02:53:26.0 |
HIP 85601 |
11.84 |
| 2026-06-09 00:00 |
17:28:51.19 |
+02:53:27.8 |
HIP 85601 |
12.14 |
| 2026-06-09 12:00 |
17:28:49.64 |
+02:53:29.5 |
HIP 85601 |
12.44 |
| 2026-06-10 00:00 |
17:28:48.09 |
+02:53:31.1 |
HIP 85601 |
12.75 |
| 2026-06-10 12:00 |
17:28:46.53 |
+02:53:32.7 |
HIP 85601 |
13.06 |
| 2026-06-11 00:00 |
17:28:44.98 |
+02:53:34.1 |
HIP 85601 |
13.38 |
| 2026-06-11 12:00 |
17:28:43.43 |
+02:53:35.5 |
HIP 85601 |
13.70 |
| 2026-06-12 00:00 |
17:28:41.87 |
+02:53:36.8 |
HIP 85601 |
14.03 |
| 2026-06-12 12:00 |
17:28:40.32 |
+02:53:38.0 |
HIP 85601 |
14.36 |
| 2026-06-13 00:00 |
17:28:38.76 |
+02:53:39.1 |
HIP 85601 |
14.70 |
| 2026-06-13 12:00 |
17:28:37.20 |
+02:53:40.2 |
HIP 85601 |
15.03 |
| 2026-06-14 00:00 |
17:28:35.65 |
+02:53:41.1 |
HIP 85601 |
15.38 |
| 2026-06-14 12:00 |
17:28:34.09 |
+02:53:42.0 |
HIP 85601 |
15.72 |
| 2026-06-15 00:00 |
17:28:32.54 |
+02:53:42.8 |
HIP 85601 |
16.07 |
| 2026-06-15 12:00 |
17:28:30.98 |
+02:53:43.5 |
HIP 85601 |
16.41 |
| 2026-06-16 00:00 |
17:28:29.42 |
+02:53:44.1 |
HIP 85601 |
16.77 |
| 2026-06-16 12:00 |
17:28:27.87 |
+02:53:44.6 |
HIP 85601 |
17.12 |
| 2026-06-17 00:00 |
17:28:26.31 |
+02:53:45.1 |
HIP 85601 |
17.47 |
| 2026-06-17 12:00 |
17:28:24.76 |
+02:53:45.4 |
HIP 85601 |
17.83 |
| 2026-06-18 00:00 |
17:28:23.21 |
+02:53:45.7 |
HIP 85601 |
18.19 |
| 2026-06-18 12:00 |
17:28:21.66 |
+02:53:45.9 |
HIP 85601 |
18.55 |
| 2026-06-19 00:00 |
17:28:20.10 |
+02:53:46.0 |
HIP 85601 |
18.91 |
| 2026-06-19 12:00 |
17:28:18.56 |
+02:53:46.0 |
HIP 85601 |
19.27 |
| 2026-06-20 00:00 |
17:28:17.01 |
+02:53:45.9 |
HIP 85601 |
19.64 |
| 2026-06-20 12:00 |
17:28:15.46 |
+02:53:45.7 |
HIP 85601 |
20.00 |
| 2026-06-21 00:00 |
17:28:13.91 |
+02:53:45.5 |
HIP 85601 |
20.37 |
| 2026-06-21 12:00 |
17:28:12.37 |
+02:53:45.2 |
HIP 85601 |
20.73 |
| 2026-06-22 00:00 |
17:28:10.83 |
+02:53:44.7 |
HIP 85601 |
21.10 |