| Parameter |
Value |
| Designation |
C/2015 M1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-05-15T16:23:58.865280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:13Z |
| Obs used |
66 |
| NEO |
- |
| M1 |
15.900 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-06-30.0000000 |
| e |
0.99457925 |
| q (au) |
2.091599 |
| a (au) |
385.850445 |
| i (deg) |
57.309532 |
| Ω (om, deg) |
100.291624 |
| ω (w, deg) |
163.983025 |
| M (ma, deg) |
0.005893 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.909 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.909 |
| n |
2.000 |
| gf |
0.926 |
| gb |
-1.000 |
| k |
0.998 |
| 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) |
| 2026-03-26 00:00 |
04:42:44.55 |
-16:45:32.5 |
HIP 21715 |
44.92 |
| 2026-03-26 12:00 |
04:42:46.61 |
-16:44:45.4 |
HIP 22027 |
45.31 |
| 2026-03-27 00:00 |
04:42:48.71 |
-16:43:58.3 |
HIP 22027 |
44.39 |
| 2026-03-27 12:00 |
04:42:50.85 |
-16:43:11.5 |
HIP 22027 |
43.47 |
| 2026-03-28 00:00 |
04:42:53.02 |
-16:42:24.7 |
HIP 22027 |
42.54 |
| 2026-03-28 12:00 |
04:42:55.23 |
-16:41:38.1 |
HIP 22027 |
41.61 |
| 2026-03-29 00:00 |
04:42:57.47 |
-16:40:51.6 |
HIP 22027 |
40.69 |
| 2026-03-29 12:00 |
04:42:59.74 |
-16:40:05.2 |
HIP 22027 |
39.76 |
| 2026-03-30 00:00 |
04:43:02.05 |
-16:39:19.0 |
HIP 22027 |
38.83 |
| 2026-03-30 12:00 |
04:43:04.40 |
-16:38:32.9 |
HIP 22027 |
37.90 |
| 2026-03-31 00:00 |
04:43:06.78 |
-16:37:47.0 |
HIP 22027 |
36.97 |
| 2026-03-31 12:00 |
04:43:09.19 |
-16:37:01.2 |
HIP 22027 |
36.04 |
| 2026-04-01 00:00 |
04:43:11.64 |
-16:36:15.6 |
HIP 22027 |
35.12 |
| 2026-04-01 12:00 |
04:43:14.12 |
-16:35:30.1 |
HIP 22027 |
34.19 |
| 2026-04-02 00:00 |
04:43:16.64 |
-16:34:44.8 |
HIP 22027 |
33.26 |
| 2026-04-02 12:00 |
04:43:19.18 |
-16:33:59.6 |
HIP 22027 |
32.34 |
| 2026-04-03 00:00 |
04:43:21.76 |
-16:33:14.5 |
HIP 22027 |
31.42 |
| 2026-04-03 12:00 |
04:43:24.38 |
-16:32:29.7 |
HIP 22027 |
30.50 |
| 2026-04-04 00:00 |
04:43:27.02 |
-16:31:45.0 |
HIP 22027 |
29.59 |
| 2026-04-04 12:00 |
04:43:29.70 |
-16:31:00.4 |
HIP 22027 |
28.68 |
| 2026-04-05 00:00 |
04:43:32.41 |
-16:30:16.1 |
HIP 22027 |
27.78 |
| 2026-04-05 12:00 |
04:43:35.16 |
-16:29:31.9 |
HIP 22027 |
26.88 |
| 2026-04-06 00:00 |
04:43:37.93 |
-16:28:47.8 |
HIP 22027 |
25.99 |
| 2026-04-06 12:00 |
04:43:40.74 |
-16:28:04.0 |
HIP 22027 |
25.11 |
| 2026-04-07 00:00 |
04:43:43.58 |
-16:27:20.3 |
HIP 22027 |
24.24 |
| 2026-04-07 12:00 |
04:43:46.45 |
-16:26:36.8 |
HIP 22027 |
23.38 |
| 2026-04-08 00:00 |
04:43:49.35 |
-16:25:53.5 |
HIP 22027 |
22.53 |
| 2026-04-08 12:00 |
04:43:52.28 |
-16:25:10.3 |
HIP 22027 |
21.69 |
| 2026-04-09 00:00 |
04:43:55.24 |
-16:24:27.4 |
HIP 22027 |
20.88 |
| 2026-04-09 12:00 |
04:43:58.24 |
-16:23:44.6 |
HIP 22027 |
20.08 |
| 2026-04-10 00:00 |
04:44:01.26 |
-16:23:02.0 |
HIP 22027 |
19.31 |
| 2026-04-10 12:00 |
04:44:04.31 |
-16:22:19.6 |
HIP 22027 |
18.56 |
| 2026-04-11 00:00 |
04:44:07.40 |
-16:21:37.5 |
HIP 22027 |
17.85 |
| 2026-04-11 12:00 |
04:44:10.51 |
-16:20:55.5 |
HIP 22027 |
17.16 |
| 2026-04-12 00:00 |
04:44:13.65 |
-16:20:13.7 |
HIP 22027 |
16.52 |
| 2026-04-12 12:00 |
04:44:16.82 |
-16:19:32.1 |
HIP 22027 |
15.92 |
| 2026-04-13 00:00 |
04:44:20.02 |
-16:18:50.7 |
HIP 22052 |
15.30 |
| 2026-04-13 12:00 |
04:44:23.25 |
-16:18:09.6 |
HIP 22052 |
14.48 |
| 2026-04-14 00:00 |
04:44:26.51 |
-16:17:28.6 |
HIP 22052 |
13.68 |
| 2026-04-14 12:00 |
04:44:29.79 |
-16:16:47.8 |
HIP 22052 |
12.93 |
| 2026-04-15 00:00 |
04:44:33.11 |
-16:16:07.3 |
HIP 22052 |
12.22 |
| 2026-04-15 12:00 |
04:44:36.45 |
-16:15:27.0 |
HIP 22052 |
11.56 |
| 2026-04-16 00:00 |
04:44:39.82 |
-16:14:46.9 |
HIP 22052 |
10.97 |