| 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) |
| 2026-07-29 00:00 |
09:53:37.94 |
+16:06:23.7 |
HIP 48577 |
12.75 |
| 2026-07-29 12:00 |
09:53:53.17 |
+16:05:03.2 |
HIP 48577 |
8.85 |
| 2026-07-30 00:00 |
09:54:08.42 |
+16:03:42.7 |
HIP 48577 |
4.95 |
| 2026-07-30 12:00 |
09:54:23.70 |
+16:02:22.0 |
HIP 48577 |
1.05 |
| 2026-07-31 00:00 |
09:54:39.00 |
+16:01:01.2 |
HIP 48577 |
2.88 |
| 2026-07-31 12:00 |
09:54:54.32 |
+15:59:40.3 |
HIP 48577 |
6.80 |
| 2026-08-01 00:00 |
09:55:09.67 |
+15:58:19.3 |
HIP 48577 |
10.72 |
| 2026-08-01 12:00 |
09:55:25.03 |
+15:56:58.1 |
HIP 48577 |
14.66 |
| 2026-08-02 00:00 |
09:55:40.42 |
+15:55:36.9 |
HIP 48577 |
18.59 |
| 2026-08-02 12:00 |
09:55:55.82 |
+15:54:15.5 |
HIP 48577 |
22.54 |
| 2026-08-03 00:00 |
09:56:11.25 |
+15:52:54.1 |
HIP 48858 |
25.93 |
| 2026-08-03 12:00 |
09:56:26.69 |
+15:51:32.5 |
HIP 48858 |
22.01 |
| 2026-08-04 00:00 |
09:56:42.16 |
+15:50:10.8 |
HIP 48858 |
18.09 |
| 2026-08-04 12:00 |
09:56:57.64 |
+15:48:49.1 |
HIP 48858 |
14.19 |
| 2026-08-05 00:00 |
09:57:13.14 |
+15:47:27.2 |
HIP 48858 |
10.34 |
| 2026-08-05 12:00 |
09:57:28.66 |
+15:46:05.3 |
HIP 48858 |
6.63 |
| 2026-08-06 00:00 |
09:57:44.20 |
+15:44:43.3 |
HIP 48858 |
3.54 |
| 2026-08-06 12:00 |
09:57:59.75 |
+15:43:21.1 |
HIP 48858 |
3.58 |
| 2026-08-07 00:00 |
09:58:15.32 |
+15:41:58.9 |
HIP 48858 |
6.70 |
| 2026-08-07 12:00 |
09:58:30.90 |
+15:40:36.6 |
HIP 48858 |
10.43 |
| 2026-08-08 00:00 |
09:58:46.50 |
+15:39:14.3 |
HIP 48858 |
14.31 |
| 2026-08-08 12:00 |
09:59:02.12 |
+15:37:51.8 |
HIP 48858 |
18.25 |
| 2026-08-09 00:00 |
09:59:17.74 |
+15:36:29.3 |
HIP 48858 |
22.21 |
| 2026-08-09 12:00 |
09:59:33.38 |
+15:35:06.7 |
HIP 49048 |
21.84 |
| 2026-08-10 00:00 |
09:59:49.04 |
+15:33:44.1 |
HIP 49048 |
20.82 |
| 2026-08-10 12:00 |
10:00:04.70 |
+15:32:21.4 |
HIP 49108 |
19.93 |
| 2026-08-11 00:00 |
10:00:20.38 |
+15:30:58.6 |
HIP 49108 |
17.23 |
| 2026-08-11 12:00 |
10:00:36.07 |
+15:29:35.8 |
HIP 49108 |
15.13 |
| 2026-08-12 00:00 |
10:00:51.77 |
+15:28:12.9 |
HIP 49108 |
13.90 |
| 2026-08-12 12:00 |
10:01:07.47 |
+15:26:49.9 |
HIP 49108 |
13.78 |
| 2026-08-13 00:00 |
10:01:23.19 |
+15:25:26.9 |
HIP 49168 |
10.35 |
| 2026-08-13 12:00 |
10:01:38.92 |
+15:24:03.9 |
HIP 49168 |
6.31 |
| 2026-08-14 00:00 |
10:01:54.65 |
+15:22:40.9 |
HIP 49168 |
2.29 |
| 2026-08-14 12:00 |
10:02:10.39 |
+15:21:17.7 |
HIP 49168 |
1.79 |
| 2026-08-15 00:00 |
10:02:26.14 |
+15:19:54.6 |
HIP 49168 |
5.82 |
| 2026-08-15 12:00 |
10:02:41.90 |
+15:18:31.4 |
HIP 49168 |
9.86 |
| 2026-08-16 00:00 |
10:02:57.66 |
+15:17:08.2 |
HIP 49168 |
13.90 |
| 2026-08-16 12:00 |
10:03:13.42 |
+15:15:45.0 |
HIP 49168 |
17.95 |
| 2026-08-17 00:00 |
10:03:29.19 |
+15:14:21.8 |
HIP 49168 |
22.00 |
| 2026-08-17 12:00 |
10:03:44.96 |
+15:12:58.5 |
HIP 49395 |
19.57 |
| 2026-08-18 00:00 |
10:04:00.74 |
+15:11:35.3 |
HIP 49395 |
15.54 |
| 2026-08-18 12:00 |
10:04:16.52 |
+15:10:12.0 |
HIP 49395 |
11.53 |
| 2026-08-19 00:00 |
10:04:32.30 |
+15:08:48.7 |
HIP 49395 |
7.56 |