| Parameter |
Value |
| Designation |
P/2017 G2 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2017-06-13T21:56:20.866560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:32Z |
| Obs used |
165 |
| NEO |
- |
| M1 |
12.900 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-05-16.0000000 |
| e |
0.65031280 |
| q (au) |
2.846253 |
| a (au) |
8.139426 |
| i (deg) |
47.906245 |
| Ω (om, deg) |
79.819627 |
| ω (w, deg) |
105.939134 |
| M (ma, deg) |
358.772777 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.648 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.648 |
| n |
6.000 |
| 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 |
01:40:53.82 |
-46:04:50.7 |
HIP 7898 |
8.43 |
| 2026-09-20 12:00 |
01:40:44.27 |
-46:05:58.0 |
HIP 7898 |
10.42 |
| 2026-09-21 00:00 |
01:40:34.66 |
-46:07:04.5 |
HIP 7898 |
12.43 |
| 2026-09-21 12:00 |
01:40:24.99 |
-46:08:10.2 |
HIP 7898 |
14.43 |
| 2026-09-22 00:00 |
01:40:15.26 |
-46:09:15.1 |
HIP 7898 |
16.43 |
| 2026-09-22 12:00 |
01:40:05.48 |
-46:10:19.1 |
HIP 7898 |
18.43 |
| 2026-09-23 00:00 |
01:39:55.63 |
-46:11:22.2 |
HIP 7743 |
19.36 |
| 2026-09-23 12:00 |
01:39:45.73 |
-46:12:24.5 |
HIP 7743 |
18.19 |
| 2026-09-24 00:00 |
01:39:35.78 |
-46:13:25.9 |
HIP 7743 |
17.18 |
| 2026-09-24 12:00 |
01:39:25.77 |
-46:14:26.4 |
HIP 7743 |
16.38 |
| 2026-09-25 00:00 |
01:39:15.71 |
-46:15:26.1 |
HIP 7743 |
15.80 |
| 2026-09-25 12:00 |
01:39:05.60 |
-46:16:24.8 |
HIP 7743 |
15.48 |
| 2026-09-26 00:00 |
01:38:55.44 |
-46:17:22.7 |
HIP 7610 |
15.25 |
| 2026-09-26 12:00 |
01:38:45.23 |
-46:18:19.7 |
HIP 7610 |
15.12 |
| 2026-09-27 00:00 |
01:38:34.97 |
-46:19:15.7 |
HIP 7610 |
15.23 |
| 2026-09-27 12:00 |
01:38:24.67 |
-46:20:10.9 |
HIP 7610 |
15.58 |
| 2026-09-28 00:00 |
01:38:14.31 |
-46:21:05.1 |
HIP 7610 |
16.16 |
| 2026-09-28 12:00 |
01:38:03.91 |
-46:21:58.4 |
HIP 7610 |
16.94 |
| 2026-09-29 00:00 |
01:37:53.47 |
-46:22:50.8 |
HIP 7610 |
17.90 |
| 2026-09-29 12:00 |
01:37:42.99 |
-46:23:42.2 |
HIP 7610 |
19.01 |
| 2026-09-30 00:00 |
01:37:32.46 |
-46:24:32.7 |
HIP 7610 |
20.25 |
| 2026-09-30 12:00 |
01:37:21.89 |
-46:25:22.2 |
HIP 7610 |
21.58 |
| 2026-10-01 00:00 |
01:37:11.28 |
-46:26:10.8 |
HIP 7610 |
23.01 |
| 2026-10-01 12:00 |
01:37:00.63 |
-46:26:58.4 |
HIP 7610 |
24.50 |
| 2026-10-02 00:00 |
01:36:49.95 |
-46:27:45.0 |
HIP 7610 |
26.05 |
| 2026-10-02 12:00 |
01:36:39.22 |
-46:28:30.6 |
HIP 7610 |
27.64 |
| 2026-10-03 00:00 |
01:36:28.47 |
-46:29:15.3 |
HIP 7610 |
29.28 |
| 2026-10-03 12:00 |
01:36:17.67 |
-46:29:59.0 |
HIP 7610 |
30.95 |
| 2026-10-04 00:00 |
01:36:06.85 |
-46:30:41.7 |
HIP 7610 |
32.65 |
| 2026-10-04 12:00 |
01:35:55.99 |
-46:31:23.3 |
HIP 7610 |
34.37 |
| 2026-10-05 00:00 |
01:35:45.10 |
-46:32:04.0 |
HIP 7610 |
36.11 |
| 2026-10-05 12:00 |
01:35:34.18 |
-46:32:43.7 |
HIP 7610 |
37.86 |
| 2026-10-06 00:00 |
01:35:23.23 |
-46:33:22.3 |
HIP 7176 |
39.16 |
| 2026-10-06 12:00 |
01:35:12.26 |
-46:34:00.0 |
HIP 7176 |
38.16 |
| 2026-10-07 00:00 |
01:35:01.26 |
-46:34:36.5 |
HIP 7176 |
37.23 |
| 2026-10-07 12:00 |
01:34:50.23 |
-46:35:12.0 |
HIP 7176 |
36.36 |
| 2026-10-08 00:00 |
01:34:39.18 |
-46:35:46.5 |
HIP 7176 |
35.57 |
| 2026-10-08 12:00 |
01:34:28.11 |
-46:36:20.0 |
HIP 7176 |
34.87 |
| 2026-10-09 00:00 |
01:34:17.02 |
-46:36:52.4 |
HIP 7176 |
34.24 |
| 2026-10-09 12:00 |
01:34:05.90 |
-46:37:23.7 |
HIP 7072 |
33.44 |
| 2026-10-10 00:00 |
01:33:54.77 |
-46:37:54.0 |
HIP 7072 |
31.93 |
| 2026-10-10 12:00 |
01:33:43.63 |
-46:38:23.2 |
HIP 7072 |
30.47 |
| 2026-10-11 00:00 |
01:33:32.46 |
-46:38:51.3 |
HIP 7072 |
29.05 |