| Parameter |
Value |
| Designation |
C/2015 D2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-09-27T14:47:50.671680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:07Z |
| Obs used |
68 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
12.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-03-24.0000000 |
| e |
0.56825603 |
| q (au) |
5.606049 |
| a (au) |
12.984662 |
| i (deg) |
31.834348 |
| Ω (om, deg) |
162.858947 |
| ω (w, deg) |
291.923116 |
| M (ma, deg) |
11.425219 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.640 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.640 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.639 |
| k |
0.800 |
| δ90 |
9.439 |
| 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 |
16:20:04.64 |
+09:59:28.0 |
HIP 79923 |
20.10 |
| 2026-09-20 12:00 |
16:20:08.27 |
+09:58:32.2 |
HIP 79923 |
20.64 |
| 2026-09-21 00:00 |
16:20:11.94 |
+09:57:36.5 |
HIP 79923 |
21.26 |
| 2026-09-21 12:00 |
16:20:15.66 |
+09:56:40.8 |
HIP 79923 |
21.95 |
| 2026-09-22 00:00 |
16:20:19.43 |
+09:55:45.3 |
HIP 79923 |
22.70 |
| 2026-09-22 12:00 |
16:20:23.25 |
+09:54:49.9 |
HIP 79923 |
23.52 |
| 2026-09-23 00:00 |
16:20:27.13 |
+09:53:54.6 |
HIP 79923 |
24.39 |
| 2026-09-23 12:00 |
16:20:31.05 |
+09:52:59.3 |
HIP 79923 |
25.32 |
| 2026-09-24 00:00 |
16:20:35.02 |
+09:52:04.2 |
HIP 79923 |
26.29 |
| 2026-09-24 12:00 |
16:20:39.04 |
+09:51:09.2 |
HIP 80202 |
26.07 |
| 2026-09-25 00:00 |
16:20:43.10 |
+09:50:14.3 |
HIP 80202 |
25.22 |
| 2026-09-25 12:00 |
16:20:47.22 |
+09:49:19.5 |
HIP 80202 |
24.40 |
| 2026-09-26 00:00 |
16:20:51.38 |
+09:48:24.9 |
HIP 80202 |
23.62 |
| 2026-09-26 12:00 |
16:20:55.60 |
+09:47:30.3 |
HIP 80202 |
22.88 |
| 2026-09-27 00:00 |
16:20:59.85 |
+09:46:35.9 |
HIP 80202 |
22.19 |
| 2026-09-27 12:00 |
16:21:04.16 |
+09:45:41.6 |
HIP 80202 |
21.55 |
| 2026-09-28 00:00 |
16:21:08.52 |
+09:44:47.5 |
HIP 80202 |
20.98 |
| 2026-09-28 12:00 |
16:21:12.92 |
+09:43:53.4 |
HIP 80202 |
20.48 |
| 2026-09-29 00:00 |
16:21:17.36 |
+09:42:59.5 |
HIP 80202 |
20.05 |
| 2026-09-29 12:00 |
16:21:21.86 |
+09:42:05.8 |
HIP 80202 |
19.71 |
| 2026-09-30 00:00 |
16:21:26.40 |
+09:41:12.2 |
HIP 80202 |
19.45 |
| 2026-09-30 12:00 |
16:21:30.99 |
+09:40:18.7 |
HIP 80202 |
19.29 |
| 2026-10-01 00:00 |
16:21:35.62 |
+09:39:25.4 |
HIP 80139 |
18.92 |
| 2026-10-01 12:00 |
16:21:40.30 |
+09:38:32.3 |
HIP 80139 |
18.25 |
| 2026-10-02 00:00 |
16:21:45.02 |
+09:37:39.2 |
HIP 80139 |
17.68 |
| 2026-10-02 12:00 |
16:21:49.79 |
+09:36:46.4 |
HIP 80139 |
17.23 |
| 2026-10-03 00:00 |
16:21:54.60 |
+09:35:53.7 |
HIP 80139 |
16.90 |
| 2026-10-03 12:00 |
16:21:59.46 |
+09:35:01.2 |
HIP 80139 |
16.70 |
| 2026-10-04 00:00 |
16:22:04.37 |
+09:34:08.9 |
HIP 80139 |
16.64 |
| 2026-10-04 12:00 |
16:22:09.31 |
+09:33:16.7 |
HIP 80139 |
16.72 |
| 2026-10-05 00:00 |
16:22:14.31 |
+09:32:24.7 |
HIP 80139 |
16.95 |
| 2026-10-05 12:00 |
16:22:19.34 |
+09:31:32.8 |
HIP 80139 |
17.31 |
| 2026-10-06 00:00 |
16:22:24.42 |
+09:30:41.2 |
HIP 80139 |
17.81 |
| 2026-10-06 12:00 |
16:22:29.54 |
+09:29:49.7 |
HIP 80139 |
18.43 |
| 2026-10-07 00:00 |
16:22:34.71 |
+09:28:58.5 |
HIP 80139 |
19.16 |
| 2026-10-07 12:00 |
16:22:39.92 |
+09:28:07.4 |
HIP 80139 |
19.99 |
| 2026-10-08 00:00 |
16:22:45.17 |
+09:27:16.5 |
HIP 80139 |
20.92 |
| 2026-10-08 12:00 |
16:22:50.46 |
+09:26:25.8 |
HIP 80139 |
21.93 |
| 2026-10-09 00:00 |
16:22:55.79 |
+09:25:35.4 |
HIP 80139 |
23.01 |
| 2026-10-09 12:00 |
16:23:01.17 |
+09:24:45.1 |
HIP 80139 |
24.15 |
| 2026-10-10 00:00 |
16:23:06.59 |
+09:23:55.0 |
HIP 80139 |
25.35 |
| 2026-10-10 12:00 |
16:23:12.04 |
+09:23:05.2 |
HIP 80139 |
26.60 |
| 2026-10-11 00:00 |
16:23:17.54 |
+09:22:15.5 |
HIP 80203 |
26.52 |