| Parameter |
Value |
| Designation |
P/2015 R2 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-06-08T04:48:20.191680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:14Z |
| Obs used |
24 |
| NEO |
- |
| M1 |
15.600 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-09-13.0000000 |
| e |
0.45202974 |
| q (au) |
2.473558 |
| a (au) |
4.514038 |
| i (deg) |
15.551673 |
| Ω (om, deg) |
168.668252 |
| ω (w, deg) |
149.648582 |
| M (ma, deg) |
9.947882 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.425 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.425 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.548 |
| k |
1.000 |
| 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) |
| 2026-09-20 00:00 |
05:55:38.80 |
+07:36:18.9 |
HIP 27989 |
13.83 |
| 2026-09-20 12:00 |
05:55:49.04 |
+07:34:39.4 |
HIP 27989 |
14.04 |
| 2026-09-21 00:00 |
05:55:59.08 |
+07:32:59.5 |
HIP 27989 |
14.82 |
| 2026-09-21 12:00 |
05:56:08.92 |
+07:31:19.4 |
HIP 27989 |
16.09 |
| 2026-09-22 00:00 |
05:56:18.55 |
+07:29:38.9 |
HIP 27989 |
17.71 |
| 2026-09-22 12:00 |
05:56:27.98 |
+07:27:58.1 |
HIP 27989 |
19.58 |
| 2026-09-23 00:00 |
05:56:37.21 |
+07:26:17.1 |
HIP 27989 |
21.63 |
| 2026-09-23 12:00 |
05:56:46.22 |
+07:24:35.8 |
HIP 27989 |
23.78 |
| 2026-09-24 00:00 |
05:56:55.04 |
+07:22:54.2 |
HIP 27989 |
26.01 |
| 2026-09-24 12:00 |
05:57:03.64 |
+07:21:12.3 |
HIP 27989 |
28.29 |
| 2026-09-25 00:00 |
05:57:12.04 |
+07:19:30.2 |
HIP 27989 |
30.58 |
| 2026-09-25 12:00 |
05:57:20.23 |
+07:17:47.8 |
HIP 27989 |
32.89 |
| 2026-09-26 00:00 |
05:57:28.21 |
+07:16:05.2 |
HIP 28377 |
33.14 |
| 2026-09-26 12:00 |
05:57:35.98 |
+07:14:22.4 |
HIP 28377 |
31.35 |
| 2026-09-27 00:00 |
05:57:43.53 |
+07:12:39.3 |
HIP 28377 |
29.73 |
| 2026-09-27 12:00 |
05:57:50.88 |
+07:10:56.0 |
HIP 28377 |
28.29 |
| 2026-09-28 00:00 |
05:57:58.02 |
+07:09:12.5 |
HIP 28377 |
27.07 |
| 2026-09-28 12:00 |
05:58:04.94 |
+07:07:28.8 |
HIP 28377 |
26.07 |
| 2026-09-29 00:00 |
05:58:11.65 |
+07:05:44.9 |
HIP 28377 |
25.31 |
| 2026-09-29 12:00 |
05:58:18.14 |
+07:04:00.7 |
HIP 28377 |
24.82 |
| 2026-09-30 00:00 |
05:58:24.42 |
+07:02:16.5 |
HIP 28377 |
24.58 |
| 2026-09-30 12:00 |
05:58:30.48 |
+07:00:32.0 |
HIP 28384 |
23.55 |
| 2026-10-01 00:00 |
05:58:36.33 |
+06:58:47.4 |
HIP 28384 |
21.35 |
| 2026-10-01 12:00 |
05:58:41.96 |
+06:57:02.6 |
HIP 28384 |
19.20 |
| 2026-10-02 00:00 |
05:58:47.37 |
+06:55:17.6 |
HIP 28384 |
17.12 |
| 2026-10-02 12:00 |
05:58:52.56 |
+06:53:32.6 |
HIP 28384 |
15.11 |
| 2026-10-03 00:00 |
05:58:57.53 |
+06:51:47.4 |
HIP 28384 |
13.21 |
| 2026-10-03 12:00 |
05:59:02.28 |
+06:50:02.0 |
HIP 28384 |
11.45 |
| 2026-10-04 00:00 |
05:59:06.81 |
+06:48:16.6 |
HIP 28384 |
9.89 |
| 2026-10-04 12:00 |
05:59:11.11 |
+06:46:31.0 |
HIP 28384 |
8.60 |
| 2026-10-05 00:00 |
05:59:15.20 |
+06:44:45.4 |
HIP 28384 |
7.71 |
| 2026-10-05 12:00 |
05:59:19.06 |
+06:42:59.7 |
HIP 28384 |
7.35 |
| 2026-10-06 00:00 |
05:59:22.69 |
+06:41:13.9 |
HIP 28384 |
7.56 |
| 2026-10-06 12:00 |
05:59:26.10 |
+06:39:28.1 |
HIP 28384 |
8.29 |
| 2026-10-07 00:00 |
05:59:29.29 |
+06:37:42.2 |
HIP 28384 |
9.41 |
| 2026-10-07 12:00 |
05:59:32.25 |
+06:35:56.2 |
HIP 28384 |
10.78 |
| 2026-10-08 00:00 |
05:59:34.98 |
+06:34:10.3 |
HIP 28384 |
12.30 |
| 2026-10-08 12:00 |
05:59:37.49 |
+06:32:24.3 |
HIP 28384 |
13.93 |
| 2026-10-09 00:00 |
05:59:39.77 |
+06:30:38.3 |
HIP 28384 |
15.61 |
| 2026-10-09 12:00 |
05:59:41.82 |
+06:28:52.3 |
HIP 28384 |
17.34 |
| 2026-10-10 00:00 |
05:59:43.64 |
+06:27:06.3 |
HIP 28384 |
19.08 |
| 2026-10-10 12:00 |
05:59:45.23 |
+06:25:20.4 |
HIP 28384 |
20.84 |
| 2026-10-11 00:00 |
05:59:46.60 |
+06:23:34.5 |
HIP 28384 |
22.61 |