| Parameter |
Value |
| Designation |
C/2015 M3 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-08-26T05:34:05.033280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:13Z |
| Obs used |
150 |
| NEO |
- |
| M1 |
14.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-09-03.0000000 |
| e |
0.97327847 |
| q (au) |
3.552414 |
| a (au) |
132.942015 |
| i (deg) |
65.951065 |
| Ω (om, deg) |
143.092842 |
| ω (w, deg) |
123.762544 |
| M (ma, deg) |
0.004995 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.907 + 2.182\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.907 |
| n |
2.182 |
| gf |
1.000 |
| gb |
-0.511 |
| 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 |
03:31:13.20 |
-46:24:55.4 |
HIP 16391 |
12.03 |
| 2026-03-26 12:00 |
03:31:18.48 |
-46:23:57.5 |
HIP 16391 |
13.11 |
| 2026-03-27 00:00 |
03:31:23.79 |
-46:23:00.0 |
HIP 16391 |
14.24 |
| 2026-03-27 12:00 |
03:31:29.15 |
-46:22:02.8 |
HIP 16391 |
15.39 |
| 2026-03-28 00:00 |
03:31:34.55 |
-46:21:05.9 |
HIP 16391 |
16.57 |
| 2026-03-28 12:00 |
03:31:39.98 |
-46:20:09.4 |
HIP 16391 |
17.76 |
| 2026-03-29 00:00 |
03:31:45.46 |
-46:19:13.2 |
HIP 16391 |
18.97 |
| 2026-03-29 12:00 |
03:31:50.97 |
-46:18:17.4 |
HIP 16391 |
20.20 |
| 2026-03-30 00:00 |
03:31:56.53 |
-46:17:21.9 |
HIP 16391 |
21.43 |
| 2026-03-30 12:00 |
03:32:02.12 |
-46:16:26.7 |
HIP 16391 |
22.67 |
| 2026-03-31 00:00 |
03:32:07.75 |
-46:15:32.0 |
HIP 16391 |
23.92 |
| 2026-03-31 12:00 |
03:32:13.42 |
-46:14:37.6 |
HIP 16391 |
25.17 |
| 2026-04-01 00:00 |
03:32:19.12 |
-46:13:43.5 |
HIP 16391 |
26.44 |
| 2026-04-01 12:00 |
03:32:24.86 |
-46:12:49.8 |
HIP 16391 |
27.70 |
| 2026-04-02 00:00 |
03:32:30.64 |
-46:11:56.5 |
HIP 16391 |
28.97 |
| 2026-04-02 12:00 |
03:32:36.45 |
-46:11:03.6 |
HIP 16391 |
30.25 |
| 2026-04-03 00:00 |
03:32:42.30 |
-46:10:11.0 |
HIP 16391 |
31.52 |
| 2026-04-03 12:00 |
03:32:48.19 |
-46:09:18.8 |
HIP 16391 |
32.80 |
| 2026-04-04 00:00 |
03:32:54.11 |
-46:08:27.0 |
HIP 16391 |
34.09 |
| 2026-04-04 12:00 |
03:33:00.07 |
-46:07:35.6 |
HIP 16533 |
34.61 |
| 2026-04-05 00:00 |
03:33:06.06 |
-46:06:44.5 |
HIP 16533 |
33.81 |
| 2026-04-05 12:00 |
03:33:12.08 |
-46:05:53.9 |
HIP 16533 |
33.04 |
| 2026-04-06 00:00 |
03:33:18.14 |
-46:05:03.6 |
HIP 16533 |
32.32 |
| 2026-04-06 12:00 |
03:33:24.23 |
-46:04:13.7 |
HIP 16533 |
31.65 |
| 2026-04-07 00:00 |
03:33:30.35 |
-46:03:24.2 |
HIP 16533 |
31.03 |
| 2026-04-07 12:00 |
03:33:36.51 |
-46:02:35.2 |
HIP 16533 |
30.47 |
| 2026-04-08 00:00 |
03:33:42.70 |
-46:01:46.5 |
HIP 16533 |
29.96 |
| 2026-04-08 12:00 |
03:33:48.92 |
-46:00:58.2 |
HIP 16533 |
29.52 |
| 2026-04-09 00:00 |
03:33:55.17 |
-46:00:10.3 |
HIP 16533 |
29.14 |
| 2026-04-09 12:00 |
03:34:01.46 |
-45:59:22.9 |
HIP 16533 |
28.83 |
| 2026-04-10 00:00 |
03:34:07.77 |
-45:58:35.8 |
HIP 16533 |
28.58 |
| 2026-04-10 12:00 |
03:34:14.12 |
-45:57:49.2 |
HIP 16533 |
28.41 |
| 2026-04-11 00:00 |
03:34:20.49 |
-45:57:03.0 |
HIP 16533 |
28.31 |
| 2026-04-11 12:00 |
03:34:26.90 |
-45:56:17.2 |
HIP 16533 |
28.29 |
| 2026-04-12 00:00 |
03:34:33.33 |
-45:55:31.8 |
HIP 16533 |
28.33 |
| 2026-04-12 12:00 |
03:34:39.80 |
-45:54:46.9 |
HIP 16533 |
28.45 |
| 2026-04-13 00:00 |
03:34:46.29 |
-45:54:02.4 |
HIP 16533 |
28.65 |
| 2026-04-13 12:00 |
03:34:52.81 |
-45:53:18.3 |
HIP 16533 |
28.91 |
| 2026-04-14 00:00 |
03:34:59.36 |
-45:52:34.6 |
HIP 16804 |
29.17 |
| 2026-04-14 12:00 |
03:35:05.94 |
-45:51:51.4 |
HIP 16804 |
28.00 |
| 2026-04-15 00:00 |
03:35:12.54 |
-45:51:08.7 |
HIP 16804 |
26.86 |
| 2026-04-15 12:00 |
03:35:19.17 |
-45:50:26.3 |
HIP 16804 |
25.73 |
| 2026-04-16 00:00 |
03:35:25.83 |
-45:49:44.5 |
HIP 16804 |
24.64 |