| Parameter |
Value |
| Designation |
C/2021 G3 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-10-18T17:46:41.067840Z |
| Orbit solution date (soln_date, UTC) |
2022-12-08T23:43:00Z |
| Obs used |
63 |
| NEO |
- |
| M1 |
7.600 |
| K1 |
14.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-07-12.0000000 |
| e |
1.00119266 |
| q (au) |
5.181101 |
| a (au) |
-4344.158799 |
| i (deg) |
102.884132 |
| Ω (om, deg) |
147.418441 |
| ω (w, deg) |
10.663883 |
| M (ma, deg) |
-0.000340 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.019 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.019 |
| n |
2.000 |
| gf |
0.997 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
9.990 |
| 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) |
| 2026-06-01 00:00 |
21:39:37.46 |
+58:35:29.8 |
HIP 106770 |
18.39 |
| 2026-06-01 12:00 |
21:39:32.58 |
+58:36:54.5 |
HIP 106770 |
17.10 |
| 2026-06-02 00:00 |
21:39:27.55 |
+58:38:18.8 |
HIP 106770 |
15.85 |
| 2026-06-02 12:00 |
21:39:22.38 |
+58:39:42.6 |
HIP 106770 |
14.65 |
| 2026-06-03 00:00 |
21:39:17.07 |
+58:41:05.9 |
HIP 106770 |
13.50 |
| 2026-06-03 12:00 |
21:39:11.62 |
+58:42:28.7 |
HIP 106770 |
12.42 |
| 2026-06-04 00:00 |
21:39:06.03 |
+58:43:51.1 |
HIP 106770 |
11.44 |
| 2026-06-04 12:00 |
21:39:00.29 |
+58:45:12.9 |
HIP 106770 |
10.58 |
| 2026-06-05 00:00 |
21:38:54.42 |
+58:46:34.2 |
HIP 106770 |
9.86 |
| 2026-06-05 12:00 |
21:38:48.40 |
+58:47:55.1 |
HIP 106770 |
9.34 |
| 2026-06-06 00:00 |
21:38:42.25 |
+58:49:15.3 |
HIP 106770 |
9.04 |
| 2026-06-06 12:00 |
21:38:35.95 |
+58:50:35.1 |
HIP 106770 |
8.98 |
| 2026-06-07 00:00 |
21:38:29.51 |
+58:51:54.3 |
HIP 106770 |
9.17 |
| 2026-06-07 12:00 |
21:38:22.93 |
+58:53:12.9 |
HIP 106770 |
9.60 |
| 2026-06-08 00:00 |
21:38:16.22 |
+58:54:31.0 |
HIP 106770 |
10.23 |
| 2026-06-08 12:00 |
21:38:09.36 |
+58:55:48.5 |
HIP 106770 |
11.04 |
| 2026-06-09 00:00 |
21:38:02.36 |
+58:57:05.4 |
HIP 106770 |
11.98 |
| 2026-06-09 12:00 |
21:37:55.22 |
+58:58:21.7 |
HIP 106830 |
11.94 |
| 2026-06-10 00:00 |
21:37:47.95 |
+58:59:37.4 |
HIP 106830 |
10.96 |
| 2026-06-10 12:00 |
21:37:40.53 |
+59:00:52.5 |
HIP 106830 |
10.14 |
| 2026-06-11 00:00 |
21:37:32.98 |
+59:02:07.0 |
HIP 106830 |
9.53 |
| 2026-06-11 12:00 |
21:37:25.29 |
+59:03:20.8 |
HIP 106830 |
9.17 |
| 2026-06-12 00:00 |
21:37:17.46 |
+59:04:34.0 |
HIP 106830 |
9.10 |
| 2026-06-12 12:00 |
21:37:09.49 |
+59:05:46.5 |
HIP 106830 |
9.32 |
| 2026-06-13 00:00 |
21:37:01.38 |
+59:06:58.4 |
HIP 106830 |
9.81 |
| 2026-06-13 12:00 |
21:36:53.14 |
+59:08:09.6 |
HIP 106830 |
10.54 |
| 2026-06-14 00:00 |
21:36:44.77 |
+59:09:20.1 |
HIP 106830 |
11.47 |
| 2026-06-14 12:00 |
21:36:36.25 |
+59:10:29.9 |
HIP 106830 |
12.54 |
| 2026-06-15 00:00 |
21:36:27.60 |
+59:11:39.0 |
HIP 106830 |
13.73 |
| 2026-06-15 12:00 |
21:36:18.82 |
+59:12:47.4 |
HIP 106530 |
14.78 |
| 2026-06-16 00:00 |
21:36:09.90 |
+59:13:55.0 |
HIP 106530 |
14.31 |
| 2026-06-16 12:00 |
21:36:00.85 |
+59:15:01.9 |
HIP 106530 |
14.00 |
| 2026-06-17 00:00 |
21:35:51.67 |
+59:16:08.1 |
HIP 106530 |
13.84 |
| 2026-06-17 12:00 |
21:35:42.36 |
+59:17:13.5 |
HIP 106530 |
13.85 |
| 2026-06-18 00:00 |
21:35:32.91 |
+59:18:18.2 |
HIP 106530 |
14.04 |
| 2026-06-18 12:00 |
21:35:23.33 |
+59:19:22.1 |
HIP 106478 |
13.93 |
| 2026-06-19 00:00 |
21:35:13.63 |
+59:20:25.2 |
HIP 106478 |
12.31 |
| 2026-06-19 12:00 |
21:35:03.79 |
+59:21:27.5 |
HIP 106478 |
10.69 |
| 2026-06-20 00:00 |
21:34:53.83 |
+59:22:29.0 |
HIP 106478 |
9.06 |
| 2026-06-20 12:00 |
21:34:43.73 |
+59:23:29.8 |
HIP 106478 |
7.42 |
| 2026-06-21 00:00 |
21:34:33.52 |
+59:24:29.7 |
HIP 106478 |
5.78 |
| 2026-06-21 12:00 |
21:34:23.17 |
+59:25:28.7 |
HIP 106478 |
4.14 |
| 2026-06-22 00:00 |
21:34:12.70 |
+59:26:27.0 |
HIP 106478 |
2.49 |