| Parameter |
Value |
| Designation |
C/2015 D3 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-05-01T09:15:21.309120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:07Z |
| Obs used |
313 |
| NEO |
- |
| M1 |
10.900 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2016-09-03.0000000 |
| e |
1.00219956 |
| q (au) |
8.148902 |
| a (au) |
-3704.795712 |
| i (deg) |
128.506522 |
| Ω (om, deg) |
156.980044 |
| ω (w, deg) |
2.885623 |
| M (ma, deg) |
0.000545 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.026 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.026 |
| n |
2.000 |
| gf |
0.907 |
| gb |
-0.987 |
| k |
1.000 |
| δ90 |
1.000 |
| 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) |
| 2026-07-29 00:00 |
01:06:52.29 |
+60:58:18.2 |
HIP 5139 |
14.22 |
| 2026-07-29 12:00 |
01:06:47.62 |
+60:59:02.4 |
HIP 5139 |
14.56 |
| 2026-07-30 00:00 |
01:06:42.87 |
+60:59:46.3 |
HIP 5139 |
14.94 |
| 2026-07-30 12:00 |
01:06:38.03 |
+61:00:30.0 |
HIP 5139 |
15.36 |
| 2026-07-31 00:00 |
01:06:33.11 |
+61:01:13.3 |
HIP 5139 |
15.82 |
| 2026-07-31 12:00 |
01:06:28.09 |
+61:01:56.2 |
HIP 5139 |
16.31 |
| 2026-08-01 00:00 |
01:06:22.99 |
+61:02:38.9 |
HIP 5139 |
16.83 |
| 2026-08-01 12:00 |
01:06:17.80 |
+61:03:21.2 |
HIP 5139 |
17.37 |
| 2026-08-02 00:00 |
01:06:12.52 |
+61:04:03.1 |
HIP 5139 |
17.95 |
| 2026-08-02 12:00 |
01:06:07.15 |
+61:04:44.8 |
HIP 4962 |
18.16 |
| 2026-08-03 00:00 |
01:06:01.70 |
+61:05:26.0 |
HIP 4962 |
17.52 |
| 2026-08-03 12:00 |
01:05:56.16 |
+61:06:06.9 |
HIP 4962 |
16.90 |
| 2026-08-04 00:00 |
01:05:50.53 |
+61:06:47.5 |
HIP 4962 |
16.30 |
| 2026-08-04 12:00 |
01:05:44.81 |
+61:07:27.7 |
HIP 4962 |
15.73 |
| 2026-08-05 00:00 |
01:05:39.01 |
+61:08:07.5 |
HIP 4962 |
15.18 |
| 2026-08-05 12:00 |
01:05:33.12 |
+61:08:47.0 |
HIP 4962 |
14.67 |
| 2026-08-06 00:00 |
01:05:27.15 |
+61:09:26.0 |
HIP 4956 |
14.03 |
| 2026-08-06 12:00 |
01:05:21.09 |
+61:10:04.7 |
HIP 4956 |
13.18 |
| 2026-08-07 00:00 |
01:05:14.94 |
+61:10:43.0 |
HIP 4956 |
12.34 |
| 2026-08-07 12:00 |
01:05:08.71 |
+61:11:20.9 |
HIP 4956 |
11.51 |
| 2026-08-08 00:00 |
01:05:02.39 |
+61:11:58.5 |
HIP 4956 |
10.71 |
| 2026-08-08 12:00 |
01:04:55.98 |
+61:12:35.6 |
HIP 4956 |
9.92 |
| 2026-08-09 00:00 |
01:04:49.49 |
+61:13:12.3 |
HIP 4956 |
9.16 |
| 2026-08-09 12:00 |
01:04:42.92 |
+61:13:48.6 |
HIP 4956 |
8.44 |
| 2026-08-10 00:00 |
01:04:36.26 |
+61:14:24.4 |
HIP 4956 |
7.77 |
| 2026-08-10 12:00 |
01:04:29.51 |
+61:14:59.9 |
HIP 4956 |
7.17 |
| 2026-08-11 00:00 |
01:04:22.68 |
+61:15:34.9 |
HIP 4956 |
6.65 |
| 2026-08-11 12:00 |
01:04:15.77 |
+61:16:09.5 |
HIP 4956 |
6.24 |
| 2026-08-12 00:00 |
01:04:08.77 |
+61:16:43.6 |
HIP 4956 |
5.96 |
| 2026-08-12 12:00 |
01:04:01.69 |
+61:17:17.4 |
HIP 4956 |
5.84 |
| 2026-08-13 00:00 |
01:03:54.53 |
+61:17:50.6 |
HIP 4956 |
5.88 |
| 2026-08-13 12:00 |
01:03:47.29 |
+61:18:23.4 |
HIP 4956 |
6.09 |
| 2026-08-14 00:00 |
01:03:39.96 |
+61:18:55.8 |
HIP 4956 |
6.45 |
| 2026-08-14 12:00 |
01:03:32.55 |
+61:19:27.7 |
HIP 4956 |
6.94 |
| 2026-08-15 00:00 |
01:03:25.06 |
+61:19:59.1 |
HIP 4956 |
7.53 |
| 2026-08-15 12:00 |
01:03:17.49 |
+61:20:30.1 |
HIP 4956 |
8.21 |
| 2026-08-16 00:00 |
01:03:09.84 |
+61:21:00.6 |
HIP 4956 |
8.95 |
| 2026-08-16 12:00 |
01:03:02.11 |
+61:21:30.6 |
HIP 4956 |
9.75 |
| 2026-08-17 00:00 |
01:02:54.30 |
+61:22:00.1 |
HIP 4956 |
10.59 |
| 2026-08-17 12:00 |
01:02:46.41 |
+61:22:29.1 |
HIP 4956 |
11.46 |
| 2026-08-18 00:00 |
01:02:38.45 |
+61:22:57.7 |
HIP 4956 |
12.36 |
| 2026-08-18 12:00 |
01:02:30.41 |
+61:23:25.8 |
HIP 4956 |
13.28 |
| 2026-08-19 00:00 |
01:02:22.28 |
+61:23:53.3 |
HIP 4956 |
14.23 |