| Parameter |
Value |
| Designation |
C/2012 CH17 (MOSS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2012-09-28T05:20:29.244480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:03Z |
| Obs used |
627 |
| NEO |
- |
| M1 |
14.000 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-04-06.0000000 |
| e |
0.99998818 |
| q (au) |
1.296093 |
| a (au) |
109657.782316 |
| i (deg) |
27.744192 |
| Ω (om, deg) |
125.984715 |
| ω (w, deg) |
137.993552 |
| M (ma, deg) |
359.999995 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.872 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.872 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
1.000 |
| 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) |
| 2026-09-20 00:00 |
04:30:29.40 |
-03:48:11.2 |
HIP 20942 |
29.17 |
| 2026-09-20 12:00 |
04:30:28.36 |
-03:48:35.9 |
HIP 20942 |
28.68 |
| 2026-09-21 00:00 |
04:30:27.28 |
-03:49:00.6 |
HIP 20942 |
28.19 |
| 2026-09-21 12:00 |
04:30:26.18 |
-03:49:25.3 |
HIP 20942 |
27.70 |
| 2026-09-22 00:00 |
04:30:25.04 |
-03:49:50.0 |
HIP 20942 |
27.20 |
| 2026-09-22 12:00 |
04:30:23.87 |
-03:50:14.8 |
HIP 20942 |
26.69 |
| 2026-09-23 00:00 |
04:30:22.67 |
-03:50:39.5 |
HIP 20942 |
26.18 |
| 2026-09-23 12:00 |
04:30:21.44 |
-03:51:04.2 |
HIP 20942 |
25.67 |
| 2026-09-24 00:00 |
04:30:20.18 |
-03:51:28.9 |
HIP 20942 |
25.15 |
| 2026-09-24 12:00 |
04:30:18.89 |
-03:51:53.6 |
HIP 20942 |
24.63 |
| 2026-09-25 00:00 |
04:30:17.57 |
-03:52:18.3 |
HIP 20942 |
24.11 |
| 2026-09-25 12:00 |
04:30:16.22 |
-03:52:43.0 |
HIP 20942 |
23.58 |
| 2026-09-26 00:00 |
04:30:14.84 |
-03:53:07.6 |
HIP 20942 |
23.05 |
| 2026-09-26 12:00 |
04:30:13.43 |
-03:53:32.3 |
HIP 20942 |
22.51 |
| 2026-09-27 00:00 |
04:30:11.99 |
-03:53:56.9 |
HIP 20942 |
21.97 |
| 2026-09-27 12:00 |
04:30:10.52 |
-03:54:21.5 |
HIP 20942 |
21.43 |
| 2026-09-28 00:00 |
04:30:09.02 |
-03:54:46.1 |
HIP 20942 |
20.88 |
| 2026-09-28 12:00 |
04:30:07.49 |
-03:55:10.7 |
HIP 20942 |
20.33 |
| 2026-09-29 00:00 |
04:30:05.93 |
-03:55:35.2 |
HIP 20942 |
19.78 |
| 2026-09-29 12:00 |
04:30:04.35 |
-03:55:59.7 |
HIP 20942 |
19.22 |
| 2026-09-30 00:00 |
04:30:02.73 |
-03:56:24.2 |
HIP 20942 |
18.66 |
| 2026-09-30 12:00 |
04:30:01.08 |
-03:56:48.7 |
HIP 20942 |
18.10 |
| 2026-10-01 00:00 |
04:29:59.40 |
-03:57:13.1 |
HIP 20942 |
17.54 |
| 2026-10-01 12:00 |
04:29:57.70 |
-03:57:37.5 |
HIP 20942 |
16.97 |
| 2026-10-02 00:00 |
04:29:55.96 |
-03:58:01.9 |
HIP 20942 |
16.41 |
| 2026-10-02 12:00 |
04:29:54.20 |
-03:58:26.2 |
HIP 20942 |
15.84 |
| 2026-10-03 00:00 |
04:29:52.41 |
-03:58:50.5 |
HIP 20942 |
15.27 |
| 2026-10-03 12:00 |
04:29:50.59 |
-03:59:14.7 |
HIP 20942 |
14.71 |
| 2026-10-04 00:00 |
04:29:48.74 |
-03:59:38.9 |
HIP 20942 |
14.14 |
| 2026-10-04 12:00 |
04:29:46.86 |
-04:00:03.0 |
HIP 20942 |
13.58 |
| 2026-10-05 00:00 |
04:29:44.95 |
-04:00:27.1 |
HIP 20942 |
13.01 |
| 2026-10-05 12:00 |
04:29:43.02 |
-04:00:51.2 |
HIP 20942 |
12.46 |
| 2026-10-06 00:00 |
04:29:41.05 |
-04:01:15.2 |
HIP 20942 |
11.91 |
| 2026-10-06 12:00 |
04:29:39.06 |
-04:01:39.1 |
HIP 20942 |
11.36 |
| 2026-10-07 00:00 |
04:29:37.04 |
-04:02:03.0 |
HIP 20942 |
10.82 |
| 2026-10-07 12:00 |
04:29:35.00 |
-04:02:26.8 |
HIP 20942 |
10.30 |
| 2026-10-08 00:00 |
04:29:32.92 |
-04:02:50.6 |
HIP 20942 |
9.79 |
| 2026-10-08 12:00 |
04:29:30.82 |
-04:03:14.3 |
HIP 20942 |
9.29 |
| 2026-10-09 00:00 |
04:29:28.69 |
-04:03:37.9 |
HIP 20942 |
8.82 |
| 2026-10-09 12:00 |
04:29:26.54 |
-04:04:01.5 |
HIP 20942 |
8.37 |
| 2026-10-10 00:00 |
04:29:24.35 |
-04:04:25.0 |
HIP 20942 |
7.96 |
| 2026-10-10 12:00 |
04:29:22.14 |
-04:04:48.4 |
HIP 20942 |
7.58 |
| 2026-10-11 00:00 |
04:29:19.91 |
-04:05:11.8 |
HIP 20942 |
7.25 |