C/2015 J2 (PANSTARRS)
| Parameter |
Value |
| Designation |
C/2015 J2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-09-08T21:55:57.529920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:10Z |
| Obs used |
99 |
| NEO |
- |
| M1 |
7.200 |
| K1 |
14.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-07-15.0000000 |
| e |
0.98250509 |
| q (au) |
4.320386 |
| a (au) |
246.951051 |
| i (deg) |
17.281830 |
| Ω (om, deg) |
56.755871 |
| ω (w, deg) |
203.688946 |
| M (ma, deg) |
359.985799 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.150 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.150 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.722 |
| k |
0.800 |
| δ90 |
9.998 |
| 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) |
| 2026-02-03 00:00 |
01:57:37.64 |
+03:55:19.7 |
HIP 9156 |
4.62 |
| 2026-02-03 12:00 |
01:57:39.23 |
+03:55:41.9 |
HIP 9156 |
4.20 |
| 2026-02-04 00:00 |
01:57:40.87 |
+03:56:04.2 |
HIP 9156 |
3.79 |
| 2026-02-04 12:00 |
01:57:42.54 |
+03:56:26.7 |
HIP 9156 |
3.42 |
| 2026-02-05 00:00 |
01:57:44.25 |
+03:56:49.5 |
HIP 9156 |
3.10 |
| 2026-02-05 12:00 |
01:57:46.00 |
+03:57:12.3 |
HIP 9156 |
2.85 |
| 2026-02-06 00:00 |
01:57:47.79 |
+03:57:35.4 |
HIP 9156 |
2.70 |
| 2026-02-06 12:00 |
01:57:49.62 |
+03:57:58.7 |
HIP 9156 |
2.67 |
| 2026-02-07 00:00 |
01:57:51.49 |
+03:58:22.1 |
HIP 9156 |
2.77 |
| 2026-02-07 12:00 |
01:57:53.40 |
+03:58:45.7 |
HIP 9156 |
3.00 |
| 2026-02-08 00:00 |
01:57:55.34 |
+03:59:09.5 |
HIP 9156 |
3.32 |
| 2026-02-08 12:00 |
01:57:57.33 |
+03:59:33.4 |
HIP 9156 |
3.73 |
| 2026-02-09 00:00 |
01:57:59.35 |
+03:59:57.5 |
HIP 9156 |
4.20 |
| 2026-02-09 12:00 |
01:58:01.42 |
+04:00:21.8 |
HIP 9156 |
4.72 |
| 2026-02-10 00:00 |
01:58:03.52 |
+04:00:46.3 |
HIP 9156 |
5.27 |
| 2026-02-10 12:00 |
01:58:05.65 |
+04:01:10.9 |
HIP 9156 |
5.86 |
| 2026-02-11 00:00 |
01:58:07.83 |
+04:01:35.7 |
HIP 9156 |
6.46 |
| 2026-02-11 12:00 |
01:58:10.04 |
+04:02:00.6 |
HIP 9156 |
7.09 |
| 2026-02-12 00:00 |
01:58:12.29 |
+04:02:25.7 |
HIP 9156 |
7.74 |
| 2026-02-12 12:00 |
01:58:14.58 |
+04:02:51.0 |
HIP 9156 |
8.40 |
| 2026-02-13 00:00 |
01:58:16.91 |
+04:03:16.4 |
HIP 9156 |
9.07 |
| 2026-02-13 12:00 |
01:58:19.27 |
+04:03:42.0 |
HIP 9156 |
9.76 |
| 2026-02-14 00:00 |
01:58:21.67 |
+04:04:07.7 |
HIP 9156 |
10.47 |
| 2026-02-14 12:00 |
01:58:24.11 |
+04:04:33.6 |
HIP 9156 |
11.18 |
| 2026-02-15 00:00 |
01:58:26.58 |
+04:04:59.6 |
HIP 9156 |
11.91 |
| 2026-02-15 12:00 |
01:58:29.09 |
+04:05:25.8 |
HIP 9156 |
12.65 |
| 2026-02-16 00:00 |
01:58:31.64 |
+04:05:52.2 |
HIP 9156 |
13.39 |
| 2026-02-16 12:00 |
01:58:34.22 |
+04:06:18.6 |
HIP 9156 |
14.15 |
| 2026-02-17 00:00 |
01:58:36.83 |
+04:06:45.3 |
HIP 9156 |
14.92 |
| 2026-02-17 12:00 |
01:58:39.49 |
+04:07:12.0 |
HIP 9156 |
15.70 |
| 2026-02-18 00:00 |
01:58:42.18 |
+04:07:38.9 |
HIP 9156 |
16.49 |
| 2026-02-18 12:00 |
01:58:44.90 |
+04:08:06.0 |
HIP 9156 |
17.28 |
| 2026-02-19 00:00 |
01:58:47.66 |
+04:08:33.2 |
HIP 9156 |
18.09 |
| 2026-02-19 12:00 |
01:58:50.45 |
+04:09:00.5 |
HIP 9156 |
18.91 |
| 2026-02-20 00:00 |
01:58:53.28 |
+04:09:27.9 |
HIP 9156 |
19.73 |
| 2026-02-20 12:00 |
01:58:56.14 |
+04:09:55.5 |
HIP 9156 |
20.57 |
| 2026-02-21 00:00 |
01:58:59.03 |
+04:10:23.2 |
HIP 9156 |
21.41 |
| 2026-02-21 12:00 |
01:59:01.96 |
+04:10:51.0 |
HIP 9156 |
22.26 |
| 2026-02-22 00:00 |
01:59:04.93 |
+04:11:19.0 |
HIP 9368 |
22.64 |
| 2026-02-22 12:00 |
01:59:07.92 |
+04:11:47.1 |
HIP 9368 |
21.76 |
| 2026-02-23 00:00 |
01:59:10.95 |
+04:12:15.3 |
HIP 9368 |
20.87 |
| 2026-02-23 12:00 |
01:59:14.01 |
+04:12:43.6 |
HIP 9368 |
19.97 |
| 2026-02-24 00:00 |
01:59:17.11 |
+04:13:12.0 |
HIP 9368 |
19.06 |