| Parameter |
Value |
| Designation |
C/2019 G2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-12-10T01:37:22.817280Z |
| Orbit solution date (soln_date, UTC) |
2024-04-15T15:43:27Z |
| Obs used |
120 |
| NEO |
- |
| M1 |
16.700 |
| K1 |
5.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-04-02T10:34:13.152000Z |
| Discovery magnitude (MPC) |
21.30 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-10-14.0000000 |
| e |
0.99672459 |
| q (au) |
2.291345 |
| a (au) |
699.559136 |
| i (deg) |
159.211459 |
| Ω (om, deg) |
208.142727 |
| ω (w, deg) |
82.653435 |
| M (ma, deg) |
359.996960 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.208 + 4.325\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.208 |
| n |
4.325 |
| gf |
1.000 |
| gb |
-0.827 |
| k |
0.995 |
| 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) |
| 2026-07-29 00:00 |
23:51:54.00 |
-16:09:04.7 |
HIP 117587 |
15.51 |
| 2026-07-29 12:00 |
23:51:49.19 |
-16:09:58.8 |
HIP 117587 |
14.49 |
| 2026-07-30 00:00 |
23:51:44.34 |
-16:10:52.9 |
HIP 117587 |
13.55 |
| 2026-07-30 12:00 |
23:51:39.44 |
-16:11:47.2 |
HIP 117587 |
12.70 |
| 2026-07-31 00:00 |
23:51:34.49 |
-16:12:41.6 |
HIP 117587 |
11.96 |
| 2026-07-31 12:00 |
23:51:29.51 |
-16:13:36.1 |
HIP 117587 |
11.36 |
| 2026-08-01 00:00 |
23:51:24.47 |
-16:14:30.8 |
HIP 117587 |
10.93 |
| 2026-08-01 12:00 |
23:51:19.39 |
-16:15:25.6 |
HIP 117587 |
10.70 |
| 2026-08-02 00:00 |
23:51:14.27 |
-16:16:20.4 |
HIP 117587 |
10.67 |
| 2026-08-02 12:00 |
23:51:09.11 |
-16:17:15.4 |
HIP 117587 |
10.86 |
| 2026-08-03 00:00 |
23:51:03.90 |
-16:18:10.5 |
HIP 117587 |
11.26 |
| 2026-08-03 12:00 |
23:50:58.64 |
-16:19:05.7 |
HIP 117587 |
11.85 |
| 2026-08-04 00:00 |
23:50:53.35 |
-16:20:01.0 |
HIP 117587 |
12.61 |
| 2026-08-04 12:00 |
23:50:48.01 |
-16:20:56.4 |
HIP 117587 |
13.51 |
| 2026-08-05 00:00 |
23:50:42.63 |
-16:21:51.8 |
HIP 117587 |
14.53 |
| 2026-08-05 12:00 |
23:50:37.21 |
-16:22:47.4 |
HIP 117587 |
15.65 |
| 2026-08-06 00:00 |
23:50:31.74 |
-16:23:43.0 |
HIP 117587 |
16.84 |
| 2026-08-06 12:00 |
23:50:26.24 |
-16:24:38.7 |
HIP 117587 |
18.11 |
| 2026-08-07 00:00 |
23:50:20.69 |
-16:25:34.5 |
HIP 117587 |
19.43 |
| 2026-08-07 12:00 |
23:50:15.10 |
-16:26:30.3 |
HIP 117587 |
20.80 |
| 2026-08-08 00:00 |
23:50:09.47 |
-16:27:26.2 |
HIP 117587 |
22.22 |
| 2026-08-08 12:00 |
23:50:03.81 |
-16:28:22.2 |
HIP 117462 |
23.04 |
| 2026-08-09 00:00 |
23:49:58.10 |
-16:29:18.3 |
HIP 117462 |
22.91 |
| 2026-08-09 12:00 |
23:49:52.35 |
-16:30:14.3 |
HIP 117462 |
22.89 |
| 2026-08-10 00:00 |
23:49:46.56 |
-16:31:10.5 |
HIP 117462 |
23.00 |
| 2026-08-10 12:00 |
23:49:40.74 |
-16:32:06.6 |
HIP 117462 |
23.22 |
| 2026-08-11 00:00 |
23:49:34.88 |
-16:33:02.9 |
HIP 117391 |
22.32 |
| 2026-08-11 12:00 |
23:49:28.98 |
-16:33:59.1 |
HIP 117391 |
20.65 |
| 2026-08-12 00:00 |
23:49:23.04 |
-16:34:55.4 |
HIP 117391 |
18.98 |
| 2026-08-12 12:00 |
23:49:17.06 |
-16:35:51.7 |
HIP 117391 |
17.30 |
| 2026-08-13 00:00 |
23:49:11.05 |
-16:36:48.0 |
HIP 117391 |
15.63 |
| 2026-08-13 12:00 |
23:49:05.00 |
-16:37:44.3 |
HIP 117391 |
13.96 |
| 2026-08-14 00:00 |
23:48:58.92 |
-16:38:40.7 |
HIP 117391 |
12.30 |
| 2026-08-14 12:00 |
23:48:52.80 |
-16:39:37.0 |
HIP 117391 |
10.65 |
| 2026-08-15 00:00 |
23:48:46.65 |
-16:40:33.4 |
HIP 117391 |
9.02 |
| 2026-08-15 12:00 |
23:48:40.46 |
-16:41:29.7 |
HIP 117391 |
7.45 |
| 2026-08-16 00:00 |
23:48:34.24 |
-16:42:26.1 |
HIP 117391 |
5.96 |
| 2026-08-16 12:00 |
23:48:27.99 |
-16:43:22.4 |
HIP 117391 |
4.67 |
| 2026-08-17 00:00 |
23:48:21.70 |
-16:44:18.7 |
HIP 117391 |
3.78 |
| 2026-08-17 12:00 |
23:48:15.38 |
-16:45:15.0 |
HIP 117391 |
3.60 |
| 2026-08-18 00:00 |
23:48:09.03 |
-16:46:11.3 |
HIP 117391 |
4.25 |
| 2026-08-18 12:00 |
23:48:02.65 |
-16:47:07.6 |
HIP 117391 |
5.43 |
| 2026-08-19 00:00 |
23:47:56.24 |
-16:48:03.8 |
HIP 117391 |
6.89 |