| 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) |
| 2026-07-29 00:00 |
17:26:28.77 |
+02:49:26.6 |
HIP 85390 |
29.49 |
| 2026-07-29 12:00 |
17:26:27.64 |
+02:49:20.3 |
HIP 85390 |
29.45 |
| 2026-07-30 00:00 |
17:26:26.53 |
+02:49:13.9 |
HIP 85390 |
29.41 |
| 2026-07-30 12:00 |
17:26:25.42 |
+02:49:07.4 |
HIP 85390 |
29.38 |
| 2026-07-31 00:00 |
17:26:24.33 |
+02:49:00.9 |
HIP 85390 |
29.34 |
| 2026-07-31 12:00 |
17:26:23.24 |
+02:48:54.3 |
HIP 85390 |
29.31 |
| 2026-08-01 00:00 |
17:26:22.16 |
+02:48:47.7 |
HIP 85390 |
29.28 |
| 2026-08-01 12:00 |
17:26:21.09 |
+02:48:41.0 |
HIP 85390 |
29.24 |
| 2026-08-02 00:00 |
17:26:20.03 |
+02:48:34.2 |
HIP 85390 |
29.21 |
| 2026-08-02 12:00 |
17:26:18.98 |
+02:48:27.3 |
HIP 85390 |
29.19 |
| 2026-08-03 00:00 |
17:26:17.94 |
+02:48:20.4 |
HIP 85390 |
29.16 |
| 2026-08-03 12:00 |
17:26:16.91 |
+02:48:13.5 |
HIP 85390 |
29.13 |
| 2026-08-04 00:00 |
17:26:15.89 |
+02:48:06.4 |
HIP 85390 |
29.10 |
| 2026-08-04 12:00 |
17:26:14.88 |
+02:47:59.3 |
HIP 85390 |
29.08 |
| 2026-08-05 00:00 |
17:26:13.88 |
+02:47:52.2 |
HIP 85390 |
29.06 |
| 2026-08-05 12:00 |
17:26:12.89 |
+02:47:45.0 |
HIP 85390 |
29.03 |
| 2026-08-06 00:00 |
17:26:11.91 |
+02:47:37.7 |
HIP 85390 |
29.01 |
| 2026-08-06 12:00 |
17:26:10.94 |
+02:47:30.4 |
HIP 85390 |
28.99 |
| 2026-08-07 00:00 |
17:26:09.98 |
+02:47:23.0 |
HIP 85390 |
28.97 |
| 2026-08-07 12:00 |
17:26:09.03 |
+02:47:15.5 |
HIP 85390 |
28.94 |
| 2026-08-08 00:00 |
17:26:08.09 |
+02:47:08.0 |
HIP 85390 |
28.92 |
| 2026-08-08 12:00 |
17:26:07.16 |
+02:47:00.4 |
HIP 85390 |
28.90 |
| 2026-08-09 00:00 |
17:26:06.24 |
+02:46:52.8 |
HIP 85390 |
28.88 |
| 2026-08-09 12:00 |
17:26:05.33 |
+02:46:45.1 |
HIP 85390 |
28.87 |
| 2026-08-10 00:00 |
17:26:04.43 |
+02:46:37.4 |
HIP 85390 |
28.85 |
| 2026-08-10 12:00 |
17:26:03.54 |
+02:46:29.6 |
HIP 85390 |
28.83 |
| 2026-08-11 00:00 |
17:26:02.66 |
+02:46:21.7 |
HIP 85390 |
28.81 |
| 2026-08-11 12:00 |
17:26:01.80 |
+02:46:13.8 |
HIP 85390 |
28.79 |
| 2026-08-12 00:00 |
17:26:00.94 |
+02:46:05.9 |
HIP 85390 |
28.77 |
| 2026-08-12 12:00 |
17:26:00.10 |
+02:45:57.8 |
HIP 85390 |
28.76 |
| 2026-08-13 00:00 |
17:25:59.27 |
+02:45:49.8 |
HIP 85390 |
28.74 |
| 2026-08-13 12:00 |
17:25:58.44 |
+02:45:41.7 |
HIP 85390 |
28.72 |
| 2026-08-14 00:00 |
17:25:57.63 |
+02:45:33.5 |
HIP 85390 |
28.70 |
| 2026-08-14 12:00 |
17:25:56.83 |
+02:45:25.3 |
HIP 85390 |
28.69 |
| 2026-08-15 00:00 |
17:25:56.04 |
+02:45:17.0 |
HIP 85390 |
28.67 |
| 2026-08-15 12:00 |
17:25:55.27 |
+02:45:08.7 |
HIP 85390 |
28.65 |
| 2026-08-16 00:00 |
17:25:54.50 |
+02:45:00.3 |
HIP 85390 |
28.63 |
| 2026-08-16 12:00 |
17:25:53.75 |
+02:44:51.9 |
HIP 85390 |
28.61 |
| 2026-08-17 00:00 |
17:25:53.00 |
+02:44:43.4 |
HIP 85390 |
28.59 |
| 2026-08-17 12:00 |
17:25:52.27 |
+02:44:34.9 |
HIP 85390 |
28.57 |
| 2026-08-18 00:00 |
17:25:51.55 |
+02:44:26.3 |
HIP 85390 |
28.55 |
| 2026-08-18 12:00 |
17:25:50.84 |
+02:44:17.7 |
HIP 85390 |
28.53 |
| 2026-08-19 00:00 |
17:25:50.15 |
+02:44:09.1 |
HIP 85390 |
28.51 |