| 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 |
-0.998 |
| 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) |
| 2026-03-26 00:00 |
16:26:42.98 |
+59:18:58.0 |
HIP 80669 |
30.09 |
| 2026-03-26 12:00 |
16:26:39.40 |
+59:20:13.0 |
HIP 80669 |
29.12 |
| 2026-03-27 00:00 |
16:26:35.74 |
+59:21:27.6 |
HIP 80669 |
28.18 |
| 2026-03-27 12:00 |
16:26:32.00 |
+59:22:41.9 |
HIP 80669 |
27.29 |
| 2026-03-28 00:00 |
16:26:28.19 |
+59:23:55.9 |
HIP 80669 |
26.44 |
| 2026-03-28 12:00 |
16:26:24.30 |
+59:25:09.7 |
HIP 80669 |
25.64 |
| 2026-03-29 00:00 |
16:26:20.33 |
+59:26:23.1 |
HIP 80669 |
24.89 |
| 2026-03-29 12:00 |
16:26:16.30 |
+59:27:36.2 |
HIP 80669 |
24.20 |
| 2026-03-30 00:00 |
16:26:12.18 |
+59:28:49.0 |
HIP 80669 |
23.58 |
| 2026-03-30 12:00 |
16:26:07.99 |
+59:30:01.4 |
HIP 80669 |
23.02 |
| 2026-03-31 00:00 |
16:26:03.73 |
+59:31:13.5 |
HIP 80669 |
22.54 |
| 2026-03-31 12:00 |
16:25:59.39 |
+59:32:25.3 |
HIP 80669 |
22.13 |
| 2026-04-01 00:00 |
16:25:54.99 |
+59:33:36.8 |
HIP 80669 |
21.81 |
| 2026-04-01 12:00 |
16:25:50.50 |
+59:34:47.9 |
HIP 80669 |
21.58 |
| 2026-04-02 00:00 |
16:25:45.95 |
+59:35:58.7 |
HIP 80669 |
21.43 |
| 2026-04-02 12:00 |
16:25:41.32 |
+59:37:09.1 |
HIP 80669 |
21.37 |
| 2026-04-03 00:00 |
16:25:36.62 |
+59:38:19.2 |
HIP 80669 |
21.40 |
| 2026-04-03 12:00 |
16:25:31.85 |
+59:39:28.9 |
HIP 80669 |
21.53 |
| 2026-04-04 00:00 |
16:25:27.00 |
+59:40:38.2 |
HIP 80669 |
21.74 |
| 2026-04-04 12:00 |
16:25:22.09 |
+59:41:47.1 |
HIP 80669 |
22.03 |
| 2026-04-05 00:00 |
16:25:17.10 |
+59:42:55.7 |
HIP 80669 |
22.41 |
| 2026-04-05 12:00 |
16:25:12.04 |
+59:44:03.9 |
HIP 80669 |
22.87 |
| 2026-04-06 00:00 |
16:25:06.92 |
+59:45:11.8 |
HIP 80669 |
23.39 |
| 2026-04-06 12:00 |
16:25:01.72 |
+59:46:19.2 |
HIP 80669 |
23.99 |
| 2026-04-07 00:00 |
16:24:56.45 |
+59:47:26.2 |
HIP 80669 |
24.64 |
| 2026-04-07 12:00 |
16:24:51.12 |
+59:48:32.9 |
HIP 80669 |
25.36 |
| 2026-04-08 00:00 |
16:24:45.72 |
+59:49:39.1 |
HIP 80669 |
26.12 |
| 2026-04-08 12:00 |
16:24:40.24 |
+59:50:44.9 |
HIP 80669 |
26.94 |
| 2026-04-09 00:00 |
16:24:34.70 |
+59:51:50.3 |
HIP 80429 |
26.59 |
| 2026-04-09 12:00 |
16:24:29.10 |
+59:52:55.3 |
HIP 80429 |
25.61 |
| 2026-04-10 00:00 |
16:24:23.42 |
+59:53:59.9 |
HIP 80429 |
24.68 |
| 2026-04-10 12:00 |
16:24:17.68 |
+59:55:04.0 |
HIP 80429 |
23.78 |
| 2026-04-11 00:00 |
16:24:11.87 |
+59:56:07.7 |
HIP 80429 |
22.93 |
| 2026-04-11 12:00 |
16:24:06.00 |
+59:57:11.0 |
HIP 80429 |
22.14 |
| 2026-04-12 00:00 |
16:24:00.06 |
+59:58:13.8 |
HIP 80429 |
21.39 |
| 2026-04-12 12:00 |
16:23:54.06 |
+59:59:16.2 |
HIP 80429 |
20.72 |
| 2026-04-13 00:00 |
16:23:47.99 |
+60:00:18.2 |
HIP 80429 |
20.11 |
| 2026-04-13 12:00 |
16:23:41.86 |
+60:01:19.6 |
HIP 80429 |
19.57 |
| 2026-04-14 00:00 |
16:23:35.66 |
+60:02:20.7 |
HIP 80429 |
19.12 |
| 2026-04-14 12:00 |
16:23:29.41 |
+60:03:21.2 |
HIP 80429 |
18.75 |
| 2026-04-15 00:00 |
16:23:23.09 |
+60:04:21.3 |
HIP 80429 |
18.48 |
| 2026-04-15 12:00 |
16:23:16.71 |
+60:05:20.9 |
HIP 80429 |
18.30 |
| 2026-04-16 00:00 |
16:23:10.26 |
+60:06:20.1 |
HIP 80429 |
18.21 |