| 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 |
-0.865 |
| 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) |
| 2026-05-12 00:00 |
04:20:41.56 |
-03:12:39.0 |
HIP 20166 |
21.25 |
| 2026-05-12 12:00 |
04:20:45.24 |
-03:12:23.4 |
HIP 20166 |
22.21 |
| 2026-05-13 00:00 |
04:20:48.94 |
-03:12:07.9 |
HIP 20166 |
23.16 |
| 2026-05-13 12:00 |
04:20:52.64 |
-03:11:52.6 |
HIP 20166 |
24.12 |
| 2026-05-14 00:00 |
04:20:56.34 |
-03:11:37.5 |
HIP 20166 |
25.08 |
| 2026-05-14 12:00 |
04:21:00.06 |
-03:11:22.6 |
HIP 20166 |
26.04 |
| 2026-05-15 00:00 |
04:21:03.78 |
-03:11:07.8 |
HIP 20166 |
27.00 |
| 2026-05-15 12:00 |
04:21:07.51 |
-03:10:53.3 |
HIP 20166 |
27.96 |
| 2026-05-16 00:00 |
04:21:11.24 |
-03:10:38.9 |
HIP 20166 |
28.93 |
| 2026-05-16 12:00 |
04:21:14.98 |
-03:10:24.7 |
HIP 20166 |
29.89 |
| 2026-05-17 00:00 |
04:21:18.72 |
-03:10:10.6 |
HIP 20166 |
30.85 |
| 2026-05-17 12:00 |
04:21:22.47 |
-03:09:56.8 |
HIP 20166 |
31.82 |
| 2026-05-18 00:00 |
04:21:26.23 |
-03:09:43.1 |
HIP 20166 |
32.78 |
| 2026-05-18 12:00 |
04:21:29.99 |
-03:09:29.6 |
HIP 20166 |
33.75 |
| 2026-05-19 00:00 |
04:21:33.76 |
-03:09:16.3 |
HIP 20166 |
34.71 |
| 2026-05-19 12:00 |
04:21:37.53 |
-03:09:03.2 |
HIP 20303 |
35.24 |
| 2026-05-20 00:00 |
04:21:41.30 |
-03:08:50.2 |
HIP 20303 |
35.70 |
| 2026-05-20 12:00 |
04:21:45.08 |
-03:08:37.5 |
HIP 20303 |
36.18 |
| 2026-05-21 00:00 |
04:21:48.86 |
-03:08:24.9 |
HIP 20303 |
36.67 |
| 2026-05-21 12:00 |
04:21:52.64 |
-03:08:12.6 |
HIP 20303 |
37.18 |
| 2026-05-22 00:00 |
04:21:56.43 |
-03:08:00.4 |
HIP 20303 |
37.70 |
| 2026-05-22 12:00 |
04:22:00.22 |
-03:07:48.4 |
HIP 20303 |
38.24 |
| 2026-05-23 00:00 |
04:22:04.01 |
-03:07:36.6 |
HIP 20303 |
38.79 |
| 2026-05-23 12:00 |
04:22:07.80 |
-03:07:24.9 |
HIP 20303 |
39.36 |
| 2026-05-24 00:00 |
04:22:11.60 |
-03:07:13.5 |
HIP 20303 |
39.93 |
| 2026-05-24 12:00 |
04:22:15.40 |
-03:07:02.3 |
HIP 20303 |
40.53 |
| 2026-05-25 00:00 |
04:22:19.20 |
-03:06:51.2 |
HIP 20303 |
41.13 |
| 2026-05-25 12:00 |
04:22:23.00 |
-03:06:40.4 |
HIP 20303 |
41.74 |
| 2026-05-26 00:00 |
04:22:26.80 |
-03:06:29.7 |
HIP 20303 |
42.36 |
| 2026-05-26 12:00 |
04:22:30.61 |
-03:06:19.2 |
HIP 20507 |
42.21 |
| 2026-05-27 00:00 |
04:22:34.41 |
-03:06:08.9 |
HIP 20507 |
41.99 |
| 2026-05-27 12:00 |
04:22:38.22 |
-03:05:58.8 |
HIP 20507 |
41.78 |
| 2026-05-28 00:00 |
04:22:42.02 |
-03:05:48.9 |
HIP 20507 |
41.58 |
| 2026-05-28 12:00 |
04:22:45.83 |
-03:05:39.2 |
HIP 20507 |
41.41 |
| 2026-05-29 00:00 |
04:22:49.63 |
-03:05:29.7 |
HIP 20507 |
41.26 |
| 2026-05-29 12:00 |
04:22:53.44 |
-03:05:20.4 |
HIP 20507 |
41.12 |
| 2026-05-30 00:00 |
04:22:57.24 |
-03:05:11.3 |
HIP 20507 |
41.00 |
| 2026-05-30 12:00 |
04:23:01.05 |
-03:05:02.3 |
HIP 20507 |
40.91 |
| 2026-05-31 00:00 |
04:23:04.85 |
-03:04:53.6 |
HIP 20507 |
40.83 |
| 2026-05-31 12:00 |
04:23:08.65 |
-03:04:45.0 |
HIP 20507 |
40.77 |
| 2026-06-01 00:00 |
04:23:12.45 |
-03:04:36.7 |
HIP 20507 |
40.73 |
| 2026-06-01 12:00 |
04:23:16.25 |
-03:04:28.5 |
HIP 20507 |
40.71 |
| 2026-06-02 00:00 |
04:23:20.05 |
-03:04:20.6 |
HIP 20507 |
40.71 |