| 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) |
| 2026-05-12 00:00 |
03:41:37.95 |
-45:24:25.7 |
HIP 17160 |
11.94 |
| 2026-05-12 12:00 |
03:41:45.42 |
-45:24:09.9 |
HIP 17160 |
13.24 |
| 2026-05-13 00:00 |
03:41:52.89 |
-45:23:54.5 |
HIP 17160 |
14.55 |
| 2026-05-13 12:00 |
03:42:00.37 |
-45:23:39.7 |
HIP 17160 |
15.86 |
| 2026-05-14 00:00 |
03:42:07.85 |
-45:23:25.3 |
HIP 17160 |
17.18 |
| 2026-05-14 12:00 |
03:42:15.34 |
-45:23:11.6 |
HIP 17160 |
18.50 |
| 2026-05-15 00:00 |
03:42:22.83 |
-45:22:58.3 |
HIP 17160 |
19.82 |
| 2026-05-15 12:00 |
03:42:30.32 |
-45:22:45.6 |
HIP 17160 |
21.15 |
| 2026-05-16 00:00 |
03:42:37.81 |
-45:22:33.4 |
HIP 17160 |
22.47 |
| 2026-05-16 12:00 |
03:42:45.31 |
-45:22:21.7 |
HIP 17160 |
23.80 |
| 2026-05-17 00:00 |
03:42:52.81 |
-45:22:10.6 |
HIP 17160 |
25.12 |
| 2026-05-17 12:00 |
03:43:00.30 |
-45:22:00.0 |
HIP 17160 |
26.45 |
| 2026-05-18 00:00 |
03:43:07.80 |
-45:21:49.9 |
HIP 17160 |
27.78 |
| 2026-05-18 12:00 |
03:43:15.30 |
-45:21:40.4 |
HIP 17160 |
29.10 |
| 2026-05-19 00:00 |
03:43:22.80 |
-45:21:31.4 |
HIP 17160 |
30.43 |
| 2026-05-19 12:00 |
03:43:30.30 |
-45:21:23.0 |
HIP 17160 |
31.75 |
| 2026-05-20 00:00 |
03:43:37.80 |
-45:21:15.0 |
HIP 17160 |
33.07 |
| 2026-05-20 12:00 |
03:43:45.29 |
-45:21:07.6 |
HIP 17160 |
34.40 |
| 2026-05-21 00:00 |
03:43:52.79 |
-45:21:00.8 |
HIP 17452 |
35.21 |
| 2026-05-21 12:00 |
03:44:00.28 |
-45:20:54.4 |
HIP 17452 |
34.90 |
| 2026-05-22 00:00 |
03:44:07.77 |
-45:20:48.6 |
HIP 17452 |
34.64 |
| 2026-05-22 12:00 |
03:44:15.25 |
-45:20:43.4 |
HIP 17452 |
34.44 |
| 2026-05-23 00:00 |
03:44:22.73 |
-45:20:38.6 |
HIP 17452 |
34.30 |
| 2026-05-23 12:00 |
03:44:30.21 |
-45:20:34.4 |
HIP 17452 |
34.22 |
| 2026-05-24 00:00 |
03:44:37.68 |
-45:20:30.8 |
HIP 17452 |
34.20 |
| 2026-05-24 12:00 |
03:44:45.15 |
-45:20:27.6 |
HIP 17452 |
34.24 |
| 2026-05-25 00:00 |
03:44:52.61 |
-45:20:25.0 |
HIP 17452 |
34.34 |
| 2026-05-25 12:00 |
03:45:00.07 |
-45:20:23.0 |
HIP 17452 |
34.50 |
| 2026-05-26 00:00 |
03:45:07.52 |
-45:20:21.4 |
HIP 17452 |
34.71 |
| 2026-05-26 12:00 |
03:45:14.97 |
-45:20:20.4 |
HIP 17654 |
34.33 |
| 2026-05-27 00:00 |
03:45:22.41 |
-45:20:19.9 |
HIP 17654 |
33.71 |
| 2026-05-27 12:00 |
03:45:29.84 |
-45:20:20.0 |
HIP 17654 |
33.12 |
| 2026-05-28 00:00 |
03:45:37.26 |
-45:20:20.6 |
HIP 17654 |
32.57 |
| 2026-05-28 12:00 |
03:45:44.68 |
-45:20:21.7 |
HIP 17795 |
31.47 |
| 2026-05-29 00:00 |
03:45:52.09 |
-45:20:23.3 |
HIP 17795 |
30.24 |
| 2026-05-29 12:00 |
03:45:59.49 |
-45:20:25.5 |
HIP 17795 |
29.03 |
| 2026-05-30 00:00 |
03:46:06.88 |
-45:20:28.2 |
HIP 17795 |
27.83 |
| 2026-05-30 12:00 |
03:46:14.26 |
-45:20:31.4 |
HIP 17795 |
26.64 |
| 2026-05-31 00:00 |
03:46:21.63 |
-45:20:35.2 |
HIP 17795 |
25.47 |
| 2026-05-31 12:00 |
03:46:28.99 |
-45:20:39.4 |
HIP 17795 |
24.32 |
| 2026-06-01 00:00 |
03:46:36.34 |
-45:20:44.2 |
HIP 17795 |
23.19 |
| 2026-06-01 12:00 |
03:46:43.68 |
-45:20:49.6 |
HIP 17795 |
22.08 |
| 2026-06-02 00:00 |
03:46:51.01 |
-45:20:55.4 |
HIP 17795 |
21.00 |