| Parameter |
Value |
| Designation |
P/2015 A3 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-02-22T20:59:44.802240Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:05Z |
| Obs used |
57 |
| NEO |
Yes |
| M1 |
20.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-02-14.0000000 |
| e |
0.84590960 |
| q (au) |
1.152929 |
| a (au) |
7.482163 |
| i (deg) |
172.510659 |
| Ω (om, deg) |
277.075159 |
| ω (w, deg) |
249.619923 |
| M (ma, deg) |
359.572611 |
Magnitude
Scatter + Global Linear
$$
M_a = (20.000 + 3.323\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
20.000 |
| n |
3.323 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.939 |
| 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 |
13:30:42.14 |
-02:15:42.7 |
HIP 65943 |
7.04 |
| 2026-09-20 12:00 |
13:30:48.10 |
-02:16:24.1 |
HIP 65943 |
5.59 |
| 2026-09-21 00:00 |
13:30:54.09 |
-02:17:05.4 |
HIP 65943 |
4.28 |
| 2026-09-21 12:00 |
13:31:00.10 |
-02:17:46.8 |
HIP 65943 |
3.28 |
| 2026-09-22 00:00 |
13:31:06.14 |
-02:18:28.3 |
HIP 65943 |
2.93 |
| 2026-09-22 12:00 |
13:31:12.21 |
-02:19:09.8 |
HIP 65943 |
3.46 |
| 2026-09-23 00:00 |
13:31:18.30 |
-02:19:51.2 |
HIP 65943 |
4.58 |
| 2026-09-23 12:00 |
13:31:24.41 |
-02:20:32.8 |
HIP 65982 |
4.26 |
| 2026-09-24 00:00 |
13:31:30.55 |
-02:21:14.3 |
HIP 65982 |
3.28 |
| 2026-09-24 12:00 |
13:31:36.72 |
-02:21:55.8 |
HIP 65982 |
3.00 |
| 2026-09-25 00:00 |
13:31:42.91 |
-02:22:37.4 |
HIP 65982 |
3.59 |
| 2026-09-25 12:00 |
13:31:49.12 |
-02:23:19.0 |
HIP 65982 |
4.76 |
| 2026-09-26 00:00 |
13:31:55.35 |
-02:24:00.6 |
HIP 65982 |
6.18 |
| 2026-09-26 12:00 |
13:32:01.61 |
-02:24:42.2 |
HIP 65982 |
7.72 |
| 2026-09-27 00:00 |
13:32:07.89 |
-02:25:23.8 |
HIP 65982 |
9.32 |
| 2026-09-27 12:00 |
13:32:14.19 |
-02:26:05.4 |
HIP 66097 |
10.77 |
| 2026-09-28 00:00 |
13:32:20.51 |
-02:26:47.0 |
HIP 66097 |
9.26 |
| 2026-09-28 12:00 |
13:32:26.85 |
-02:27:28.6 |
HIP 66097 |
7.85 |
| 2026-09-29 00:00 |
13:32:33.21 |
-02:28:10.2 |
HIP 66097 |
6.58 |
| 2026-09-29 12:00 |
13:32:39.60 |
-02:28:51.7 |
HIP 66097 |
5.57 |
| 2026-09-30 00:00 |
13:32:46.00 |
-02:29:33.3 |
HIP 66097 |
4.97 |
| 2026-09-30 12:00 |
13:32:52.42 |
-02:30:14.9 |
HIP 66097 |
4.94 |
| 2026-10-01 00:00 |
13:32:58.86 |
-02:30:56.4 |
HIP 66097 |
5.50 |
| 2026-10-01 12:00 |
13:33:05.32 |
-02:31:37.9 |
HIP 66097 |
6.50 |
| 2026-10-02 00:00 |
13:33:11.80 |
-02:32:19.4 |
HIP 66097 |
7.78 |
| 2026-10-02 12:00 |
13:33:18.30 |
-02:33:00.9 |
HIP 66097 |
9.21 |
| 2026-10-03 00:00 |
13:33:24.81 |
-02:33:42.3 |
HIP 66097 |
10.75 |
| 2026-10-03 12:00 |
13:33:31.34 |
-02:34:23.7 |
HIP 66097 |
12.35 |
| 2026-10-04 00:00 |
13:33:37.88 |
-02:35:05.1 |
HIP 66097 |
14.00 |
| 2026-10-04 12:00 |
13:33:44.45 |
-02:35:46.5 |
HIP 66097 |
15.67 |
| 2026-10-05 00:00 |
13:33:51.02 |
-02:36:27.8 |
HIP 66097 |
17.37 |
| 2026-10-05 12:00 |
13:33:57.62 |
-02:37:09.0 |
HIP 66097 |
19.09 |
| 2026-10-06 00:00 |
13:34:04.22 |
-02:37:50.2 |
HIP 66293 |
17.61 |
| 2026-10-06 12:00 |
13:34:10.84 |
-02:38:31.4 |
HIP 66293 |
16.15 |
| 2026-10-07 00:00 |
13:34:17.48 |
-02:39:12.5 |
HIP 66293 |
14.77 |
| 2026-10-07 12:00 |
13:34:24.13 |
-02:39:53.6 |
HIP 66293 |
13.47 |
| 2026-10-08 00:00 |
13:34:30.79 |
-02:40:34.6 |
HIP 66293 |
12.30 |
| 2026-10-08 12:00 |
13:34:37.46 |
-02:41:15.5 |
HIP 66293 |
11.29 |
| 2026-10-09 00:00 |
13:34:44.15 |
-02:41:56.4 |
HIP 66293 |
10.50 |
| 2026-10-09 12:00 |
13:34:50.84 |
-02:42:37.2 |
HIP 66293 |
9.96 |
| 2026-10-10 00:00 |
13:34:57.55 |
-02:43:17.9 |
HIP 66293 |
9.74 |
| 2026-10-10 12:00 |
13:35:04.27 |
-02:43:58.6 |
HIP 66293 |
9.85 |
| 2026-10-11 00:00 |
13:35:11.00 |
-02:44:39.2 |
HIP 66293 |
10.27 |