C/2020 T4 (PANSTARRS)
| Parameter |
Value |
| Designation |
C/2020 T4 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-07-05T05:56:29.909760Z |
| Orbit solution date (soln_date, UTC) |
2021-07-01T22:12:53Z |
| Obs used |
171 |
| NEO |
- |
| M1 |
15.800 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-10-15T14:08:31.113600Z |
| Discovery magnitude (MPC) |
21.00 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-11-23.0000000 |
| e |
1.00004087 |
| q (au) |
2.191878 |
| a (au) |
-53626.423966 |
| i (deg) |
83.817389 |
| Ω (om, deg) |
50.622331 |
| ω (w, deg) |
79.602529 |
| M (ma, deg) |
-0.000018 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.969 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.969 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.849 |
| k |
0.999 |
| 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) |
| 2026-02-03 00:00 |
15:06:46.05 |
-50:33:54.9 |
HIP 73870 |
8.76 |
| 2026-02-03 12:00 |
15:06:46.68 |
-50:35:27.1 |
HIP 73870 |
9.17 |
| 2026-02-04 00:00 |
15:06:47.20 |
-50:36:59.2 |
HIP 73870 |
9.79 |
| 2026-02-04 12:00 |
15:06:47.61 |
-50:38:31.1 |
HIP 73870 |
10.58 |
| 2026-02-05 00:00 |
15:06:47.91 |
-50:40:02.9 |
HIP 73870 |
11.51 |
| 2026-02-05 12:00 |
15:06:48.09 |
-50:41:34.5 |
HIP 73870 |
12.54 |
| 2026-02-06 00:00 |
15:06:48.16 |
-50:43:06.0 |
HIP 73870 |
13.65 |
| 2026-02-06 12:00 |
15:06:48.11 |
-50:44:37.2 |
HIP 73870 |
14.82 |
| 2026-02-07 00:00 |
15:06:47.95 |
-50:46:08.3 |
HIP 73870 |
16.04 |
| 2026-02-07 12:00 |
15:06:47.67 |
-50:47:39.2 |
HIP 73870 |
17.29 |
| 2026-02-08 00:00 |
15:06:47.28 |
-50:49:09.9 |
HIP 73870 |
18.57 |
| 2026-02-08 12:00 |
15:06:46.77 |
-50:50:40.4 |
HIP 73870 |
19.87 |
| 2026-02-09 00:00 |
15:06:46.15 |
-50:52:10.8 |
HIP 73870 |
21.19 |
| 2026-02-09 12:00 |
15:06:45.41 |
-50:53:40.9 |
HIP 73870 |
22.53 |
| 2026-02-10 00:00 |
15:06:44.55 |
-50:55:10.7 |
HIP 74157 |
23.01 |
| 2026-02-10 12:00 |
15:06:43.57 |
-50:56:40.4 |
HIP 74157 |
23.44 |
| 2026-02-11 00:00 |
15:06:42.48 |
-50:58:09.9 |
HIP 74157 |
23.96 |
| 2026-02-11 12:00 |
15:06:41.27 |
-50:59:39.1 |
HIP 73772 |
23.66 |
| 2026-02-12 00:00 |
15:06:39.94 |
-51:01:08.0 |
HIP 73772 |
22.55 |
| 2026-02-12 12:00 |
15:06:38.50 |
-51:02:36.8 |
HIP 73772 |
21.48 |
| 2026-02-13 00:00 |
15:06:36.93 |
-51:04:05.3 |
HIP 73772 |
20.45 |
| 2026-02-13 12:00 |
15:06:35.25 |
-51:05:33.5 |
HIP 73772 |
19.46 |
| 2026-02-14 00:00 |
15:06:33.45 |
-51:07:01.5 |
HIP 73772 |
18.53 |
| 2026-02-14 12:00 |
15:06:31.53 |
-51:08:29.1 |
HIP 73772 |
17.66 |
| 2026-02-15 00:00 |
15:06:29.49 |
-51:09:56.6 |
HIP 73772 |
16.86 |
| 2026-02-15 12:00 |
15:06:27.33 |
-51:11:23.7 |
HIP 73772 |
16.14 |
| 2026-02-16 00:00 |
15:06:25.05 |
-51:12:50.6 |
HIP 73772 |
15.52 |
| 2026-02-16 12:00 |
15:06:22.65 |
-51:14:17.1 |
HIP 73866 |
14.18 |
| 2026-02-17 00:00 |
15:06:20.13 |
-51:15:43.4 |
HIP 73866 |
12.70 |
| 2026-02-17 12:00 |
15:06:17.49 |
-51:17:09.4 |
HIP 73866 |
11.22 |
| 2026-02-18 00:00 |
15:06:14.73 |
-51:18:35.0 |
HIP 73866 |
9.74 |
| 2026-02-18 12:00 |
15:06:11.84 |
-51:20:00.4 |
HIP 73866 |
8.26 |
| 2026-02-19 00:00 |
15:06:08.84 |
-51:21:25.4 |
HIP 73866 |
6.79 |
| 2026-02-19 12:00 |
15:06:05.72 |
-51:22:50.1 |
HIP 73866 |
5.31 |
| 2026-02-20 00:00 |
15:06:02.48 |
-51:24:14.4 |
HIP 73866 |
3.85 |
| 2026-02-20 12:00 |
15:05:59.12 |
-51:25:38.4 |
HIP 73866 |
2.42 |
| 2026-02-21 00:00 |
15:05:55.64 |
-51:27:02.1 |
HIP 73866 |
1.16 |
| 2026-02-21 12:00 |
15:05:52.03 |
-51:28:25.4 |
HIP 73866 |
1.12 |
| 2026-02-22 00:00 |
15:05:48.31 |
-51:29:48.3 |
HIP 73866 |
2.37 |
| 2026-02-22 12:00 |
15:05:44.47 |
-51:31:10.9 |
HIP 73866 |
3.81 |
| 2026-02-23 00:00 |
15:05:40.51 |
-51:32:33.1 |
HIP 73866 |
5.27 |
| 2026-02-23 12:00 |
15:05:36.42 |
-51:33:55.0 |
HIP 73866 |
6.76 |
| 2026-02-24 00:00 |
15:05:32.22 |
-51:35:16.4 |
HIP 73866 |
8.25 |