| 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) |
| 2026-05-12 00:00 |
09:24:50.66 |
+18:44:03.7 |
HIP 46272 |
19.75 |
| 2026-05-12 12:00 |
09:24:55.40 |
+18:43:32.0 |
HIP 46272 |
19.08 |
| 2026-05-13 00:00 |
09:25:00.25 |
+18:42:59.7 |
HIP 46272 |
18.45 |
| 2026-05-13 12:00 |
09:25:05.21 |
+18:42:27.0 |
HIP 46272 |
17.87 |
| 2026-05-14 00:00 |
09:25:10.28 |
+18:41:53.8 |
HIP 46272 |
17.36 |
| 2026-05-14 12:00 |
09:25:15.45 |
+18:41:20.1 |
HIP 46272 |
16.92 |
| 2026-05-15 00:00 |
09:25:20.73 |
+18:40:45.9 |
HIP 46272 |
16.58 |
| 2026-05-15 12:00 |
09:25:26.11 |
+18:40:11.2 |
HIP 46272 |
16.34 |
| 2026-05-16 00:00 |
09:25:31.61 |
+18:39:36.1 |
HIP 46272 |
16.20 |
| 2026-05-16 12:00 |
09:25:37.20 |
+18:39:00.5 |
HIP 46272 |
16.20 |
| 2026-05-17 00:00 |
09:25:42.90 |
+18:38:24.4 |
HIP 46272 |
16.32 |
| 2026-05-17 12:00 |
09:25:48.71 |
+18:37:47.8 |
HIP 46272 |
16.58 |
| 2026-05-18 00:00 |
09:25:54.62 |
+18:37:10.8 |
HIP 46272 |
16.97 |
| 2026-05-18 12:00 |
09:26:00.64 |
+18:36:33.3 |
HIP 46272 |
17.49 |
| 2026-05-19 00:00 |
09:26:06.75 |
+18:35:55.4 |
HIP 46272 |
18.14 |
| 2026-05-19 12:00 |
09:26:12.97 |
+18:35:17.0 |
HIP 46272 |
18.91 |
| 2026-05-20 00:00 |
09:26:19.30 |
+18:34:38.1 |
HIP 46272 |
19.80 |
| 2026-05-20 12:00 |
09:26:25.72 |
+18:33:58.8 |
HIP 46272 |
20.79 |
| 2026-05-21 00:00 |
09:26:32.24 |
+18:33:19.0 |
HIP 46357 |
21.01 |
| 2026-05-21 12:00 |
09:26:38.87 |
+18:32:38.8 |
HIP 46357 |
19.82 |
| 2026-05-22 00:00 |
09:26:45.59 |
+18:31:58.1 |
HIP 46357 |
18.71 |
| 2026-05-22 12:00 |
09:26:52.42 |
+18:31:17.0 |
HIP 46357 |
17.68 |
| 2026-05-23 00:00 |
09:26:59.34 |
+18:30:35.4 |
HIP 46357 |
16.76 |
| 2026-05-23 12:00 |
09:27:06.36 |
+18:29:53.4 |
HIP 46357 |
15.99 |
| 2026-05-24 00:00 |
09:27:13.48 |
+18:29:11.0 |
HIP 46357 |
15.38 |
| 2026-05-24 12:00 |
09:27:20.70 |
+18:28:28.1 |
HIP 46357 |
14.98 |
| 2026-05-25 00:00 |
09:27:28.01 |
+18:27:44.8 |
HIP 46357 |
14.79 |
| 2026-05-25 12:00 |
09:27:35.42 |
+18:27:01.1 |
HIP 46357 |
14.85 |
| 2026-05-26 00:00 |
09:27:42.93 |
+18:26:16.9 |
HIP 46357 |
15.16 |
| 2026-05-26 12:00 |
09:27:50.53 |
+18:25:32.3 |
HIP 46357 |
15.71 |
| 2026-05-27 00:00 |
09:27:58.22 |
+18:24:47.3 |
HIP 46357 |
16.49 |
| 2026-05-27 12:00 |
09:28:06.01 |
+18:24:01.9 |
HIP 46357 |
17.47 |
| 2026-05-28 00:00 |
09:28:13.89 |
+18:23:16.0 |
HIP 46357 |
18.63 |
| 2026-05-28 12:00 |
09:28:21.86 |
+18:22:29.8 |
HIP 46357 |
19.94 |
| 2026-05-29 00:00 |
09:28:29.93 |
+18:21:43.1 |
HIP 46357 |
21.39 |
| 2026-05-29 12:00 |
09:28:38.08 |
+18:20:56.0 |
HIP 46357 |
22.95 |
| 2026-05-30 00:00 |
09:28:46.33 |
+18:20:08.5 |
HIP 46357 |
24.61 |
| 2026-05-30 12:00 |
09:28:54.67 |
+18:19:20.6 |
HIP 46357 |
26.35 |
| 2026-05-31 00:00 |
09:29:03.10 |
+18:18:32.3 |
HIP 46662 |
25.60 |
| 2026-05-31 12:00 |
09:29:11.62 |
+18:17:43.6 |
HIP 46662 |
23.49 |
| 2026-06-01 00:00 |
09:29:20.23 |
+18:16:54.5 |
HIP 46662 |
21.38 |
| 2026-06-01 12:00 |
09:29:28.92 |
+18:16:05.0 |
HIP 46662 |
19.27 |
| 2026-06-02 00:00 |
09:29:37.71 |
+18:15:15.1 |
HIP 46662 |
17.17 |