| 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) |
| 2026-07-29 00:00 |
04:29:24.14 |
-03:11:07.6 |
HIP 20984 |
12.00 |
| 2026-07-29 12:00 |
04:29:26.27 |
-03:11:22.1 |
HIP 20984 |
11.74 |
| 2026-07-30 00:00 |
04:29:28.38 |
-03:11:36.7 |
HIP 20984 |
11.51 |
| 2026-07-30 12:00 |
04:29:30.47 |
-03:11:51.5 |
HIP 20984 |
11.31 |
| 2026-07-31 00:00 |
04:29:32.53 |
-03:12:06.5 |
HIP 20984 |
11.14 |
| 2026-07-31 12:00 |
04:29:34.57 |
-03:12:21.7 |
HIP 20984 |
11.01 |
| 2026-08-01 00:00 |
04:29:36.58 |
-03:12:37.0 |
HIP 20984 |
10.91 |
| 2026-08-01 12:00 |
04:29:38.56 |
-03:12:52.4 |
HIP 20984 |
10.84 |
| 2026-08-02 00:00 |
04:29:40.52 |
-03:13:08.1 |
HIP 20984 |
10.81 |
| 2026-08-02 12:00 |
04:29:42.45 |
-03:13:23.9 |
HIP 20984 |
10.81 |
| 2026-08-03 00:00 |
04:29:44.35 |
-03:13:39.8 |
HIP 20984 |
10.84 |
| 2026-08-03 12:00 |
04:29:46.23 |
-03:13:55.9 |
HIP 20984 |
10.91 |
| 2026-08-04 00:00 |
04:29:48.08 |
-03:14:12.2 |
HIP 20984 |
11.01 |
| 2026-08-04 12:00 |
04:29:49.91 |
-03:14:28.6 |
HIP 20984 |
11.14 |
| 2026-08-05 00:00 |
04:29:51.71 |
-03:14:45.2 |
HIP 20984 |
11.29 |
| 2026-08-05 12:00 |
04:29:53.48 |
-03:15:01.9 |
HIP 20984 |
11.47 |
| 2026-08-06 00:00 |
04:29:55.22 |
-03:15:18.8 |
HIP 20984 |
11.68 |
| 2026-08-06 12:00 |
04:29:56.94 |
-03:15:35.8 |
HIP 20984 |
11.90 |
| 2026-08-07 00:00 |
04:29:58.63 |
-03:15:53.0 |
HIP 20984 |
12.15 |
| 2026-08-07 12:00 |
04:30:00.29 |
-03:16:10.3 |
HIP 20984 |
12.42 |
| 2026-08-08 00:00 |
04:30:01.93 |
-03:16:27.8 |
HIP 20984 |
12.70 |
| 2026-08-08 12:00 |
04:30:03.54 |
-03:16:45.5 |
HIP 20984 |
13.00 |
| 2026-08-09 00:00 |
04:30:05.11 |
-03:17:03.2 |
HIP 20984 |
13.31 |
| 2026-08-09 12:00 |
04:30:06.66 |
-03:17:21.2 |
HIP 20984 |
13.64 |
| 2026-08-10 00:00 |
04:30:08.19 |
-03:17:39.2 |
HIP 20984 |
13.97 |
| 2026-08-10 12:00 |
04:30:09.68 |
-03:17:57.4 |
HIP 20984 |
14.32 |
| 2026-08-11 00:00 |
04:30:11.15 |
-03:18:15.8 |
HIP 20984 |
14.67 |
| 2026-08-11 12:00 |
04:30:12.58 |
-03:18:34.3 |
HIP 20984 |
15.04 |
| 2026-08-12 00:00 |
04:30:13.99 |
-03:18:52.9 |
HIP 20984 |
15.41 |
| 2026-08-12 12:00 |
04:30:15.37 |
-03:19:11.7 |
HIP 20984 |
15.78 |
| 2026-08-13 00:00 |
04:30:16.72 |
-03:19:30.6 |
HIP 20984 |
16.16 |
| 2026-08-13 12:00 |
04:30:18.04 |
-03:19:49.6 |
HIP 20984 |
16.55 |
| 2026-08-14 00:00 |
04:30:19.33 |
-03:20:08.8 |
HIP 20984 |
16.94 |
| 2026-08-14 12:00 |
04:30:20.59 |
-03:20:28.1 |
HIP 20984 |
17.33 |
| 2026-08-15 00:00 |
04:30:21.82 |
-03:20:47.6 |
HIP 20984 |
17.73 |
| 2026-08-15 12:00 |
04:30:23.03 |
-03:21:07.1 |
HIP 20984 |
18.12 |
| 2026-08-16 00:00 |
04:30:24.20 |
-03:21:26.8 |
HIP 20984 |
18.52 |
| 2026-08-16 12:00 |
04:30:25.34 |
-03:21:46.7 |
HIP 20984 |
18.93 |
| 2026-08-17 00:00 |
04:30:26.46 |
-03:22:06.6 |
HIP 20984 |
19.33 |
| 2026-08-17 12:00 |
04:30:27.54 |
-03:22:26.7 |
HIP 20984 |
19.73 |
| 2026-08-18 00:00 |
04:30:28.59 |
-03:22:46.9 |
HIP 20984 |
20.13 |
| 2026-08-18 12:00 |
04:30:29.62 |
-03:23:07.2 |
HIP 20984 |
20.54 |
| 2026-08-19 00:00 |
04:30:30.61 |
-03:23:27.6 |
HIP 20984 |
20.94 |