| 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 |
9.999 |
| 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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
09:29:46.58 |
+18:14:24.8 |
HIP 46662 |
15.08 |
| 2026-06-03 00:00 |
09:29:55.54 |
+18:13:34.1 |
HIP 46662 |
13.03 |
| 2026-06-03 12:00 |
09:30:04.58 |
+18:12:43.0 |
HIP 46662 |
11.06 |
| 2026-06-04 00:00 |
09:30:13.72 |
+18:11:51.5 |
HIP 46662 |
9.24 |
| 2026-06-04 12:00 |
09:30:22.93 |
+18:10:59.7 |
HIP 46662 |
7.67 |
| 2026-06-05 00:00 |
09:30:32.24 |
+18:10:07.4 |
HIP 46662 |
6.59 |
| 2026-06-05 12:00 |
09:30:41.62 |
+18:09:14.8 |
HIP 46662 |
6.26 |
| 2026-06-06 00:00 |
09:30:51.09 |
+18:08:21.8 |
HIP 46662 |
6.83 |
| 2026-06-06 12:00 |
09:31:00.65 |
+18:07:28.4 |
HIP 46662 |
8.11 |
| 2026-06-07 00:00 |
09:31:10.29 |
+18:06:34.6 |
HIP 46662 |
9.86 |
| 2026-06-07 12:00 |
09:31:20.01 |
+18:05:40.5 |
HIP 46662 |
11.88 |
| 2026-06-08 00:00 |
09:31:29.81 |
+18:04:46.0 |
HIP 46662 |
14.07 |
| 2026-06-08 12:00 |
09:31:39.69 |
+18:03:51.1 |
HIP 46662 |
16.36 |
| 2026-06-09 00:00 |
09:31:49.66 |
+18:02:55.8 |
HIP 46662 |
18.73 |
| 2026-06-09 12:00 |
09:31:59.70 |
+18:02:00.2 |
HIP 46662 |
21.16 |
| 2026-06-10 00:00 |
09:32:09.83 |
+18:01:04.2 |
HIP 46662 |
23.64 |
| 2026-06-10 12:00 |
09:32:20.03 |
+18:00:07.9 |
HIP 46900 |
23.27 |
| 2026-06-11 00:00 |
09:32:30.32 |
+17:59:11.2 |
HIP 46900 |
22.43 |
| 2026-06-11 12:00 |
09:32:40.68 |
+17:58:14.1 |
HIP 46900 |
21.87 |
| 2026-06-12 00:00 |
09:32:51.12 |
+17:57:16.6 |
HIP 46900 |
21.61 |
| 2026-06-12 12:00 |
09:33:01.64 |
+17:56:18.9 |
HIP 46900 |
21.68 |
| 2026-06-13 00:00 |
09:33:12.24 |
+17:55:20.7 |
HIP 46986 |
19.98 |
| 2026-06-13 12:00 |
09:33:22.91 |
+17:54:22.2 |
HIP 46986 |
17.65 |
| 2026-06-14 00:00 |
09:33:33.66 |
+17:53:23.4 |
HIP 46986 |
15.44 |
| 2026-06-14 12:00 |
09:33:44.48 |
+17:52:24.2 |
HIP 46986 |
13.40 |
| 2026-06-15 00:00 |
09:33:55.38 |
+17:51:24.6 |
HIP 46986 |
11.65 |
| 2026-06-15 12:00 |
09:34:06.35 |
+17:50:24.7 |
HIP 46986 |
10.35 |
| 2026-06-16 00:00 |
09:34:17.40 |
+17:49:24.5 |
HIP 46986 |
9.70 |
| 2026-06-16 12:00 |
09:34:28.52 |
+17:48:24.0 |
HIP 46986 |
9.84 |
| 2026-06-17 00:00 |
09:34:39.71 |
+17:47:23.1 |
HIP 46986 |
10.77 |
| 2026-06-17 12:00 |
09:34:50.97 |
+17:46:21.8 |
HIP 46986 |
12.31 |
| 2026-06-18 00:00 |
09:35:02.31 |
+17:45:20.3 |
HIP 46986 |
14.27 |
| 2026-06-18 12:00 |
09:35:13.71 |
+17:44:18.4 |
HIP 46986 |
16.53 |
| 2026-06-19 00:00 |
09:35:25.18 |
+17:43:16.2 |
HIP 46986 |
18.97 |
| 2026-06-19 12:00 |
09:35:36.73 |
+17:42:13.7 |
HIP 46986 |
21.55 |
| 2026-06-20 00:00 |
09:35:48.34 |
+17:41:10.9 |
HIP 46986 |
24.23 |
| 2026-06-20 12:00 |
09:36:00.01 |
+17:40:07.7 |
HIP 47138 |
26.75 |
| 2026-06-21 00:00 |
09:36:11.76 |
+17:39:04.2 |
HIP 47138 |
25.35 |
| 2026-06-21 12:00 |
09:36:23.57 |
+17:38:00.5 |
HIP 47138 |
24.23 |
| 2026-06-22 00:00 |
09:36:35.45 |
+17:36:56.4 |
HIP 47138 |
23.44 |