| 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) |
| 2026-06-01 00:00 |
16:27:52.02 |
+12:08:38.6 |
HIP 80553 |
16.79 |
| 2026-06-01 12:00 |
16:27:46.03 |
+12:08:49.1 |
HIP 80553 |
15.47 |
| 2026-06-02 00:00 |
16:27:40.04 |
+12:08:59.2 |
HIP 80553 |
14.18 |
| 2026-06-02 12:00 |
16:27:34.05 |
+12:09:08.6 |
HIP 80553 |
12.92 |
| 2026-06-03 00:00 |
16:27:28.07 |
+12:09:17.6 |
HIP 80553 |
11.70 |
| 2026-06-03 12:00 |
16:27:22.09 |
+12:09:26.1 |
HIP 80553 |
10.55 |
| 2026-06-04 00:00 |
16:27:16.11 |
+12:09:34.0 |
HIP 80553 |
9.48 |
| 2026-06-04 12:00 |
16:27:10.15 |
+12:09:41.4 |
HIP 80553 |
8.53 |
| 2026-06-05 00:00 |
16:27:04.19 |
+12:09:48.2 |
HIP 80553 |
7.73 |
| 2026-06-05 12:00 |
16:26:58.23 |
+12:09:54.5 |
HIP 80553 |
7.13 |
| 2026-06-06 00:00 |
16:26:52.29 |
+12:10:00.4 |
HIP 80553 |
6.80 |
| 2026-06-06 12:00 |
16:26:46.35 |
+12:10:05.6 |
HIP 80553 |
6.75 |
| 2026-06-07 00:00 |
16:26:40.42 |
+12:10:10.4 |
HIP 80553 |
7.01 |
| 2026-06-07 12:00 |
16:26:34.50 |
+12:10:14.6 |
HIP 80553 |
7.53 |
| 2026-06-08 00:00 |
16:26:28.59 |
+12:10:18.3 |
HIP 80553 |
8.27 |
| 2026-06-08 12:00 |
16:26:22.69 |
+12:10:21.4 |
HIP 80553 |
9.17 |
| 2026-06-09 00:00 |
16:26:16.81 |
+12:10:24.0 |
HIP 80553 |
10.19 |
| 2026-06-09 12:00 |
16:26:10.93 |
+12:10:26.1 |
HIP 80553 |
11.29 |
| 2026-06-10 00:00 |
16:26:05.07 |
+12:10:27.7 |
HIP 80553 |
12.45 |
| 2026-06-10 12:00 |
16:25:59.22 |
+12:10:28.7 |
HIP 80553 |
13.66 |
| 2026-06-11 00:00 |
16:25:53.38 |
+12:10:29.2 |
HIP 80553 |
14.89 |
| 2026-06-11 12:00 |
16:25:47.56 |
+12:10:29.2 |
HIP 80484 |
15.36 |
| 2026-06-12 00:00 |
16:25:41.75 |
+12:10:28.6 |
HIP 80484 |
15.35 |
| 2026-06-12 12:00 |
16:25:35.96 |
+12:10:27.5 |
HIP 80484 |
15.46 |
| 2026-06-13 00:00 |
16:25:30.18 |
+12:10:25.8 |
HIP 80484 |
15.69 |
| 2026-06-13 12:00 |
16:25:24.42 |
+12:10:23.7 |
HIP 80484 |
16.03 |
| 2026-06-14 00:00 |
16:25:18.68 |
+12:10:21.0 |
HIP 80484 |
16.47 |
| 2026-06-14 12:00 |
16:25:12.95 |
+12:10:17.7 |
HIP 80484 |
17.01 |
| 2026-06-15 00:00 |
16:25:07.24 |
+12:10:14.0 |
HIP 80484 |
17.64 |
| 2026-06-15 12:00 |
16:25:01.56 |
+12:10:09.7 |
HIP 80484 |
18.34 |
| 2026-06-16 00:00 |
16:24:55.89 |
+12:10:04.8 |
HIP 80484 |
19.10 |
| 2026-06-16 12:00 |
16:24:50.24 |
+12:09:59.5 |
HIP 80484 |
19.93 |
| 2026-06-17 00:00 |
16:24:44.61 |
+12:09:53.6 |
HIP 80484 |
20.80 |
| 2026-06-17 12:00 |
16:24:39.00 |
+12:09:47.2 |
HIP 80484 |
21.71 |
| 2026-06-18 00:00 |
16:24:33.42 |
+12:09:40.2 |
HIP 80484 |
22.67 |
| 2026-06-18 12:00 |
16:24:27.86 |
+12:09:32.8 |
HIP 80484 |
23.65 |
| 2026-06-19 00:00 |
16:24:22.32 |
+12:09:24.8 |
HIP 80484 |
24.66 |
| 2026-06-19 12:00 |
16:24:16.80 |
+12:09:16.3 |
HIP 80484 |
25.70 |
| 2026-06-20 00:00 |
16:24:11.31 |
+12:09:07.2 |
HIP 80484 |
26.75 |
| 2026-06-20 12:00 |
16:24:05.84 |
+12:08:57.7 |
HIP 80484 |
27.82 |
| 2026-06-21 00:00 |
16:24:00.40 |
+12:08:47.6 |
HIP 80182 |
28.01 |
| 2026-06-21 12:00 |
16:23:54.98 |
+12:08:37.0 |
HIP 80182 |
26.72 |
| 2026-06-22 00:00 |
16:23:49.59 |
+12:08:25.9 |
HIP 80182 |
25.46 |