| 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 |
0.999 |
| gb |
-0.722 |
| 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) |
| 2026-09-20 00:00 |
02:16:26.96 |
+05:36:44.3 |
HIP 10678 |
15.01 |
| 2026-09-20 12:00 |
02:16:23.67 |
+05:36:23.5 |
HIP 10678 |
15.65 |
| 2026-09-21 00:00 |
02:16:20.35 |
+05:36:02.6 |
HIP 10678 |
16.33 |
| 2026-09-21 12:00 |
02:16:17.00 |
+05:35:41.7 |
HIP 10678 |
17.03 |
| 2026-09-22 00:00 |
02:16:13.63 |
+05:35:20.7 |
HIP 10678 |
17.75 |
| 2026-09-22 12:00 |
02:16:10.23 |
+05:34:59.7 |
HIP 10678 |
18.50 |
| 2026-09-23 00:00 |
02:16:06.80 |
+05:34:38.6 |
HIP 10678 |
19.27 |
| 2026-09-23 12:00 |
02:16:03.35 |
+05:34:17.4 |
HIP 10678 |
20.06 |
| 2026-09-24 00:00 |
02:15:59.88 |
+05:33:56.2 |
HIP 10678 |
20.86 |
| 2026-09-24 12:00 |
02:15:56.38 |
+05:33:34.9 |
HIP 10678 |
21.68 |
| 2026-09-25 00:00 |
02:15:52.85 |
+05:33:13.6 |
HIP 10678 |
22.52 |
| 2026-09-25 12:00 |
02:15:49.31 |
+05:32:52.2 |
HIP 10678 |
23.37 |
| 2026-09-26 00:00 |
02:15:45.74 |
+05:32:30.8 |
HIP 10678 |
24.24 |
| 2026-09-26 12:00 |
02:15:42.14 |
+05:32:09.3 |
HIP 10678 |
25.11 |
| 2026-09-27 00:00 |
02:15:38.52 |
+05:31:47.8 |
HIP 10678 |
26.00 |
| 2026-09-27 12:00 |
02:15:34.88 |
+05:31:26.2 |
HIP 10678 |
26.90 |
| 2026-09-28 00:00 |
02:15:31.22 |
+05:31:04.6 |
HIP 10678 |
27.81 |
| 2026-09-28 12:00 |
02:15:27.53 |
+05:30:42.9 |
HIP 10678 |
28.73 |
| 2026-09-29 00:00 |
02:15:23.82 |
+05:30:21.2 |
HIP 10678 |
29.66 |
| 2026-09-29 12:00 |
02:15:20.10 |
+05:29:59.5 |
HIP 10678 |
30.60 |
| 2026-09-30 00:00 |
02:15:16.35 |
+05:29:37.8 |
HIP 10678 |
31.55 |
| 2026-09-30 12:00 |
02:15:12.57 |
+05:29:16.0 |
HIP 10333 |
31.40 |
| 2026-10-01 00:00 |
02:15:08.78 |
+05:28:54.2 |
HIP 10333 |
30.40 |
| 2026-10-01 12:00 |
02:15:04.97 |
+05:28:32.3 |
HIP 10333 |
29.40 |
| 2026-10-02 00:00 |
02:15:01.14 |
+05:28:10.4 |
HIP 10333 |
28.39 |
| 2026-10-02 12:00 |
02:14:57.28 |
+05:27:48.6 |
HIP 10333 |
27.38 |
| 2026-10-03 00:00 |
02:14:53.41 |
+05:27:26.6 |
HIP 10333 |
26.36 |
| 2026-10-03 12:00 |
02:14:49.52 |
+05:27:04.7 |
HIP 10333 |
25.34 |
| 2026-10-04 00:00 |
02:14:45.61 |
+05:26:42.8 |
HIP 10333 |
24.32 |
| 2026-10-04 12:00 |
02:14:41.68 |
+05:26:20.8 |
HIP 10333 |
23.29 |
| 2026-10-05 00:00 |
02:14:37.73 |
+05:25:58.8 |
HIP 10333 |
22.26 |
| 2026-10-05 12:00 |
02:14:33.77 |
+05:25:36.8 |
HIP 10333 |
21.23 |
| 2026-10-06 00:00 |
02:14:29.79 |
+05:25:14.8 |
HIP 10333 |
20.20 |
| 2026-10-06 12:00 |
02:14:25.79 |
+05:24:52.8 |
HIP 10333 |
19.16 |
| 2026-10-07 00:00 |
02:14:21.77 |
+05:24:30.8 |
HIP 10333 |
18.12 |
| 2026-10-07 12:00 |
02:14:17.74 |
+05:24:08.8 |
HIP 10333 |
17.08 |
| 2026-10-08 00:00 |
02:14:13.69 |
+05:23:46.8 |
HIP 10333 |
16.04 |
| 2026-10-08 12:00 |
02:14:09.63 |
+05:23:24.8 |
HIP 10333 |
15.01 |
| 2026-10-09 00:00 |
02:14:05.55 |
+05:23:02.8 |
HIP 10333 |
13.97 |
| 2026-10-09 12:00 |
02:14:01.45 |
+05:22:40.8 |
HIP 10333 |
12.94 |
| 2026-10-10 00:00 |
02:13:57.35 |
+05:22:18.8 |
HIP 10333 |
11.91 |
| 2026-10-10 12:00 |
02:13:53.22 |
+05:21:56.9 |
HIP 10333 |
10.90 |
| 2026-10-11 00:00 |
02:13:49.09 |
+05:21:34.9 |
HIP 10333 |
9.89 |