| Parameter |
Value |
| Designation |
C/2015 J1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2014-06-29T23:13:39.259200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:10Z |
| Obs used |
54 |
| NEO |
- |
| M1 |
7.500 |
| K1 |
11.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-08-08.0000000 |
| e |
1.00318272 |
| q (au) |
6.019565 |
| a (au) |
-1891.328665 |
| i (deg) |
94.998299 |
| Ω (om, deg) |
219.992187 |
| ω (w, deg) |
315.467882 |
| M (ma, deg) |
0.004841 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.428 + 5.041\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.428 |
| n |
5.041 |
| gf |
1.000 |
| gb |
-0.500 |
| 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 |
15:58:23.55 |
+58:21:28.4 |
HIP 78404 |
16.33 |
| 2026-09-20 12:00 |
15:58:27.90 |
+58:20:35.2 |
HIP 78404 |
16.11 |
| 2026-09-21 00:00 |
15:58:32.32 |
+58:19:42.2 |
HIP 78404 |
15.94 |
| 2026-09-21 12:00 |
15:58:36.79 |
+58:18:49.4 |
HIP 78404 |
15.84 |
| 2026-09-22 00:00 |
15:58:41.33 |
+58:17:56.9 |
HIP 78404 |
15.80 |
| 2026-09-22 12:00 |
15:58:45.92 |
+58:17:04.6 |
HIP 78404 |
15.82 |
| 2026-09-23 00:00 |
15:58:50.58 |
+58:16:12.6 |
HIP 78404 |
15.90 |
| 2026-09-23 12:00 |
15:58:55.30 |
+58:15:20.9 |
HIP 78404 |
16.04 |
| 2026-09-24 00:00 |
15:59:00.08 |
+58:14:29.4 |
HIP 78404 |
16.24 |
| 2026-09-24 12:00 |
15:59:04.91 |
+58:13:38.1 |
HIP 78404 |
16.50 |
| 2026-09-25 00:00 |
15:59:09.81 |
+58:12:47.1 |
HIP 78404 |
16.82 |
| 2026-09-25 12:00 |
15:59:14.76 |
+58:11:56.4 |
HIP 78404 |
17.18 |
| 2026-09-26 00:00 |
15:59:19.78 |
+58:11:06.0 |
HIP 78404 |
17.60 |
| 2026-09-26 12:00 |
15:59:24.85 |
+58:10:15.8 |
HIP 78404 |
18.06 |
| 2026-09-27 00:00 |
15:59:29.98 |
+58:09:25.9 |
HIP 78404 |
18.56 |
| 2026-09-27 12:00 |
15:59:35.16 |
+58:08:36.3 |
HIP 78404 |
19.11 |
| 2026-09-28 00:00 |
15:59:40.41 |
+58:07:47.0 |
HIP 78404 |
19.69 |
| 2026-09-28 12:00 |
15:59:45.71 |
+58:06:57.9 |
HIP 78404 |
20.30 |
| 2026-09-29 00:00 |
15:59:51.06 |
+58:06:09.2 |
HIP 78404 |
20.95 |
| 2026-09-29 12:00 |
15:59:56.48 |
+58:05:20.7 |
HIP 78404 |
21.62 |
| 2026-09-30 00:00 |
16:00:01.95 |
+58:04:32.6 |
HIP 78404 |
22.32 |
| 2026-09-30 12:00 |
16:00:07.47 |
+58:03:44.7 |
HIP 78404 |
23.04 |
| 2026-10-01 00:00 |
16:00:13.05 |
+58:02:57.2 |
HIP 78404 |
23.79 |
| 2026-10-01 12:00 |
16:00:18.69 |
+58:02:09.9 |
HIP 78404 |
24.55 |
| 2026-10-02 00:00 |
16:00:24.38 |
+58:01:23.0 |
HIP 78404 |
25.33 |
| 2026-10-02 12:00 |
16:00:30.12 |
+58:00:36.4 |
HIP 78404 |
26.13 |
| 2026-10-03 00:00 |
16:00:35.92 |
+57:59:50.1 |
HIP 78404 |
26.94 |
| 2026-10-03 12:00 |
16:00:41.77 |
+57:59:04.2 |
HIP 78404 |
27.77 |
| 2026-10-04 00:00 |
16:00:47.68 |
+57:58:18.6 |
HIP 78404 |
28.61 |
| 2026-10-04 12:00 |
16:00:53.63 |
+57:57:33.3 |
HIP 78404 |
29.46 |
| 2026-10-05 00:00 |
16:00:59.64 |
+57:56:48.3 |
HIP 78404 |
30.32 |
| 2026-10-05 12:00 |
16:01:05.71 |
+57:56:03.7 |
HIP 78404 |
31.20 |
| 2026-10-06 00:00 |
16:01:11.82 |
+57:55:19.4 |
HIP 78404 |
32.08 |
| 2026-10-06 12:00 |
16:01:17.99 |
+57:54:35.5 |
HIP 78818 |
32.85 |
| 2026-10-07 00:00 |
16:01:24.21 |
+57:53:51.9 |
HIP 78818 |
32.01 |
| 2026-10-07 12:00 |
16:01:30.47 |
+57:53:08.6 |
HIP 78818 |
31.18 |
| 2026-10-08 00:00 |
16:01:36.79 |
+57:52:25.8 |
HIP 78623 |
30.22 |
| 2026-10-08 12:00 |
16:01:43.16 |
+57:51:43.3 |
HIP 78623 |
29.24 |
| 2026-10-09 00:00 |
16:01:49.58 |
+57:51:01.1 |
HIP 78623 |
28.28 |
| 2026-10-09 12:00 |
16:01:56.05 |
+57:50:19.4 |
HIP 78623 |
27.33 |
| 2026-10-10 00:00 |
16:02:02.56 |
+57:49:38.0 |
HIP 78623 |
26.40 |
| 2026-10-10 12:00 |
16:02:09.13 |
+57:48:57.0 |
HIP 78623 |
25.49 |
| 2026-10-11 00:00 |
16:02:15.74 |
+57:48:16.3 |
HIP 78623 |
24.60 |