| Parameter |
Value |
| Designation |
322P/SOHO |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-09-04T01:32:14.300160Z |
| Orbit solution date (soln_date, UTC) |
2016-10-27T11:29:40Z |
| Obs used |
318 |
| NEO |
Yes |
| M1 |
19.000 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-06-06.0000000 |
| e |
0.97867648 |
| q (au) |
0.053656 |
| a (au) |
2.516261 |
| i (deg) |
12.589236 |
| Ω (om, deg) |
359.524488 |
| ω (w, deg) |
49.049477 |
| M (ma, deg) |
337.760659 |
Magnitude
Scatter + Global Linear
$$
M_a = (20.000 + 4.648\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
20.000 |
| n |
4.648 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
0.800 |
| δ90 |
1.000 |
| 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) |
| 2026-05-12 00:00 |
15:01:53.85 |
-30:30:06.1 |
HIP 73562 |
22.95 |
| 2026-05-12 12:00 |
15:01:19.41 |
-30:28:04.2 |
HIP 73389 |
19.81 |
| 2026-05-13 00:00 |
15:00:44.98 |
-30:26:00.6 |
HIP 73389 |
12.14 |
| 2026-05-13 12:00 |
15:00:10.56 |
-30:23:55.6 |
HIP 73389 |
4.56 |
| 2026-05-14 00:00 |
14:59:36.16 |
-30:21:48.9 |
HIP 73389 |
3.61 |
| 2026-05-14 12:00 |
14:59:01.78 |
-30:19:40.7 |
HIP 73389 |
11.15 |
| 2026-05-15 00:00 |
14:58:27.43 |
-30:17:31.0 |
HIP 73217 |
8.54 |
| 2026-05-15 12:00 |
14:57:53.11 |
-30:15:19.9 |
HIP 73217 |
0.82 |
| 2026-05-16 00:00 |
14:57:18.84 |
-30:13:07.2 |
HIP 73217 |
6.91 |
| 2026-05-16 12:00 |
14:56:44.61 |
-30:10:53.1 |
HIP 73142 |
6.22 |
| 2026-05-17 00:00 |
14:56:10.43 |
-30:08:37.6 |
HIP 73142 |
12.20 |
| 2026-05-17 12:00 |
14:55:36.30 |
-30:06:20.6 |
HIP 73142 |
19.45 |
| 2026-05-18 00:00 |
14:55:02.24 |
-30:04:02.3 |
HIP 72974 |
22.70 |
| 2026-05-18 12:00 |
14:54:28.24 |
-30:01:42.6 |
HIP 72974 |
20.58 |
| 2026-05-19 00:00 |
14:53:54.32 |
-29:59:21.6 |
HIP 72974 |
21.22 |
| 2026-05-19 12:00 |
14:53:20.47 |
-29:56:59.3 |
HIP 72708 |
18.09 |
| 2026-05-20 00:00 |
14:52:46.71 |
-29:54:35.7 |
HIP 72708 |
11.37 |
| 2026-05-20 12:00 |
14:52:13.03 |
-29:52:10.8 |
HIP 72708 |
7.08 |
| 2026-05-21 00:00 |
14:51:39.45 |
-29:49:44.7 |
HIP 72708 |
9.45 |
| 2026-05-21 12:00 |
14:51:05.96 |
-29:47:17.5 |
HIP 72708 |
15.69 |
| 2026-05-22 00:00 |
14:50:32.58 |
-29:44:49.0 |
HIP 72708 |
22.81 |
| 2026-05-22 12:00 |
14:49:59.30 |
-29:42:19.4 |
HIP 72456 |
15.74 |
| 2026-05-23 00:00 |
14:49:26.14 |
-29:39:48.7 |
HIP 72456 |
8.58 |
| 2026-05-23 12:00 |
14:48:53.09 |
-29:37:16.8 |
HIP 72456 |
3.97 |
| 2026-05-24 00:00 |
14:48:20.16 |
-29:34:44.0 |
HIP 72416 |
2.99 |
| 2026-05-24 12:00 |
14:47:47.36 |
-29:32:10.0 |
HIP 72416 |
9.82 |
| 2026-05-25 00:00 |
14:47:14.70 |
-29:29:35.1 |
HIP 72284 |
6.64 |
| 2026-05-25 12:00 |
14:46:42.16 |
-29:26:59.2 |
HIP 72284 |
4.25 |
| 2026-05-26 00:00 |
14:46:09.77 |
-29:24:22.3 |
HIP 72284 |
10.26 |
| 2026-05-26 12:00 |
14:45:37.51 |
-29:21:44.5 |
HIP 72284 |
17.46 |
| 2026-05-27 00:00 |
14:45:05.41 |
-29:19:05.8 |
HIP 72284 |
24.81 |
| 2026-05-27 12:00 |
14:44:33.46 |
-29:16:26.3 |
HIP 72054 |
25.39 |
| 2026-05-28 00:00 |
14:44:01.66 |
-29:13:45.9 |
HIP 72054 |
28.01 |
| 2026-05-28 12:00 |
14:43:30.03 |
-29:11:04.7 |
HIP 71859 |
23.12 |
| 2026-05-29 00:00 |
14:42:58.56 |
-29:08:22.7 |
HIP 71859 |
19.05 |
| 2026-05-29 12:00 |
14:42:27.25 |
-29:05:40.0 |
HIP 71859 |
17.34 |
| 2026-05-30 00:00 |
14:41:56.12 |
-29:02:56.6 |
HIP 71871 |
13.89 |
| 2026-05-30 12:00 |
14:41:25.16 |
-29:00:12.5 |
HIP 71871 |
13.53 |
| 2026-05-31 00:00 |
14:40:54.39 |
-28:57:27.7 |
HIP 71871 |
16.69 |
| 2026-05-31 12:00 |
14:40:23.79 |
-28:54:42.3 |
HIP 71688 |
17.69 |
| 2026-06-01 00:00 |
14:39:53.38 |
-28:51:56.3 |
HIP 71688 |
13.39 |
| 2026-06-01 12:00 |
14:39:23.17 |
-28:49:09.7 |
HIP 71688 |
12.21 |
| 2026-06-02 00:00 |
14:38:53.14 |
-28:46:22.6 |
HIP 71688 |
14.86 |