| Parameter |
Value |
| Designation |
P/2015 M2 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-08-31T03:13:30.483840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:13Z |
| Obs used |
152 |
| NEO |
- |
| M1 |
7.000 |
| K1 |
11.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2016-01-31.0000000 |
| e |
0.17907655 |
| q (au) |
5.912783 |
| a (au) |
7.202599 |
| i (deg) |
3.973865 |
| Ω (om, deg) |
86.611339 |
| ω (w, deg) |
224.786932 |
| M (ma, deg) |
7.794352 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.209 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.209 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.779 |
| k |
0.800 |
| δ90 |
10.000 |
| 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 |
09:25:55.87 |
+18:53:53.0 |
HIP 46272 |
1.62 |
| 2026-03-26 12:00 |
09:25:49.90 |
+18:54:13.1 |
HIP 46272 |
3.03 |
| 2026-03-27 00:00 |
09:25:44.04 |
+18:54:32.7 |
HIP 46272 |
4.44 |
| 2026-03-27 12:00 |
09:25:38.27 |
+18:54:51.7 |
HIP 46272 |
5.84 |
| 2026-03-28 00:00 |
09:25:32.62 |
+18:55:10.1 |
HIP 46272 |
7.20 |
| 2026-03-28 12:00 |
09:25:27.07 |
+18:55:28.0 |
HIP 46272 |
8.55 |
| 2026-03-29 00:00 |
09:25:21.62 |
+18:55:45.3 |
HIP 46272 |
9.87 |
| 2026-03-29 12:00 |
09:25:16.28 |
+18:56:02.0 |
HIP 46272 |
11.16 |
| 2026-03-30 00:00 |
09:25:11.05 |
+18:56:18.1 |
HIP 46272 |
12.42 |
| 2026-03-30 12:00 |
09:25:05.93 |
+18:56:33.7 |
HIP 46272 |
13.66 |
| 2026-03-31 00:00 |
09:25:00.91 |
+18:56:48.7 |
HIP 46272 |
14.87 |
| 2026-03-31 12:00 |
09:24:56.01 |
+18:57:03.1 |
HIP 46272 |
16.06 |
| 2026-04-01 00:00 |
09:24:51.21 |
+18:57:16.9 |
HIP 46272 |
17.21 |
| 2026-04-01 12:00 |
09:24:46.52 |
+18:57:30.1 |
HIP 46272 |
18.34 |
| 2026-04-02 00:00 |
09:24:41.95 |
+18:57:42.8 |
HIP 46272 |
19.45 |
| 2026-04-02 12:00 |
09:24:37.48 |
+18:57:54.9 |
HIP 46272 |
20.52 |
| 2026-04-03 00:00 |
09:24:33.12 |
+18:58:06.4 |
HIP 46272 |
21.57 |
| 2026-04-03 12:00 |
09:24:28.88 |
+18:58:17.3 |
HIP 46272 |
22.59 |
| 2026-04-04 00:00 |
09:24:24.75 |
+18:58:27.7 |
HIP 46272 |
23.58 |
| 2026-04-04 12:00 |
09:24:20.73 |
+18:58:37.4 |
HIP 46272 |
24.55 |
| 2026-04-05 00:00 |
09:24:16.82 |
+18:58:46.6 |
HIP 46272 |
25.48 |
| 2026-04-05 12:00 |
09:24:13.02 |
+18:58:55.2 |
HIP 46272 |
26.39 |
| 2026-04-06 00:00 |
09:24:09.34 |
+18:59:03.3 |
HIP 46272 |
27.27 |
| 2026-04-06 12:00 |
09:24:05.77 |
+18:59:10.7 |
HIP 46272 |
28.12 |
| 2026-04-07 00:00 |
09:24:02.31 |
+18:59:17.6 |
HIP 46272 |
28.95 |
| 2026-04-07 12:00 |
09:23:58.97 |
+18:59:23.9 |
HIP 46104 |
29.20 |
| 2026-04-08 00:00 |
09:23:55.75 |
+18:59:29.6 |
HIP 46104 |
29.16 |
| 2026-04-08 12:00 |
09:23:52.64 |
+18:59:34.8 |
HIP 46104 |
29.15 |
| 2026-04-09 00:00 |
09:23:49.64 |
+18:59:39.4 |
HIP 46104 |
29.17 |
| 2026-04-09 12:00 |
09:23:46.76 |
+18:59:43.3 |
HIP 46104 |
29.20 |
| 2026-04-10 00:00 |
09:23:43.99 |
+18:59:46.7 |
HIP 46104 |
29.26 |
| 2026-04-10 12:00 |
09:23:41.34 |
+18:59:49.6 |
HIP 46104 |
29.34 |
| 2026-04-11 00:00 |
09:23:38.81 |
+18:59:51.8 |
HIP 46104 |
29.43 |
| 2026-04-11 12:00 |
09:23:36.39 |
+18:59:53.5 |
HIP 46104 |
29.54 |
| 2026-04-12 00:00 |
09:23:34.10 |
+18:59:54.6 |
HIP 45917 |
29.47 |
| 2026-04-12 12:00 |
09:23:31.91 |
+18:59:55.1 |
HIP 45917 |
29.03 |
| 2026-04-13 00:00 |
09:23:29.85 |
+18:59:55.1 |
HIP 45917 |
28.62 |
| 2026-04-13 12:00 |
09:23:27.90 |
+18:59:54.4 |
HIP 45917 |
28.22 |
| 2026-04-14 00:00 |
09:23:26.07 |
+18:59:53.2 |
HIP 45917 |
27.84 |
| 2026-04-14 12:00 |
09:23:24.36 |
+18:59:51.4 |
HIP 45917 |
27.49 |
| 2026-04-15 00:00 |
09:23:22.77 |
+18:59:49.1 |
HIP 45917 |
27.15 |
| 2026-04-15 12:00 |
09:23:21.29 |
+18:59:46.1 |
HIP 45917 |
26.83 |
| 2026-04-16 00:00 |
09:23:19.94 |
+18:59:42.6 |
HIP 45917 |
26.54 |