C/2020 F2 (ATLAS)
| Parameter |
Value |
| Designation |
C/2020 F2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-07-15T21:40:02.058240Z |
| Orbit solution date (soln_date, UTC) |
2025-12-02T15:12:33Z |
| Obs used |
1648 |
| NEO |
- |
| M1 |
6.300 |
| K1 |
7.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-04-06.0000000 |
| e |
1.00483272 |
| q (au) |
8.817053 |
| a (au) |
-1824.449923 |
| i (deg) |
163.583675 |
| Ω (om, deg) |
250.267950 |
| ω (w, deg) |
48.361340 |
| M (ma, deg) |
-0.001276 |
Magnitude
Scatter + Global Linear
$$
M_a = (-1.882 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-1.882 |
| n |
6.000 |
| gf |
0.898 |
| gb |
-0.928 |
| k |
1.000 |
| δ90 |
4.766 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2019-05-27 |
2022-07-14 |
+9.9520 |
-9.598 |
| 2022-07-16 |
2025-04-26 |
+13.5771 |
-13.028 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
10:14:21.90 |
+29:21:54.8 |
HIP 50303 |
24.75 |
| 2026-02-03 12:00 |
10:14:05.76 |
+29:23:24.2 |
HIP 50303 |
28.45 |
| 2026-02-04 00:00 |
10:13:49.58 |
+29:24:53.2 |
HIP 49947 |
26.01 |
| 2026-02-04 12:00 |
10:13:33.37 |
+29:26:21.7 |
HIP 49947 |
22.32 |
| 2026-02-05 00:00 |
10:13:17.11 |
+29:27:49.9 |
HIP 49947 |
18.69 |
| 2026-02-05 12:00 |
10:13:00.83 |
+29:29:17.5 |
HIP 49947 |
15.15 |
| 2026-02-06 00:00 |
10:12:44.51 |
+29:30:44.8 |
HIP 49947 |
11.80 |
| 2026-02-06 12:00 |
10:12:28.15 |
+29:32:11.5 |
HIP 49947 |
8.83 |
| 2026-02-07 00:00 |
10:12:11.77 |
+29:33:37.8 |
HIP 49947 |
6.80 |
| 2026-02-07 12:00 |
10:11:55.35 |
+29:35:03.6 |
HIP 49947 |
6.62 |
| 2026-02-08 00:00 |
10:11:38.90 |
+29:36:29.0 |
HIP 49947 |
8.43 |
| 2026-02-08 12:00 |
10:11:22.43 |
+29:37:53.8 |
HIP 49947 |
11.30 |
| 2026-02-09 00:00 |
10:11:05.93 |
+29:39:18.1 |
HIP 49947 |
14.63 |
| 2026-02-09 12:00 |
10:10:49.41 |
+29:40:42.0 |
HIP 49947 |
18.16 |
| 2026-02-10 00:00 |
10:10:32.86 |
+29:42:05.3 |
HIP 49947 |
21.80 |
| 2026-02-10 12:00 |
10:10:16.29 |
+29:43:28.1 |
HIP 49947 |
25.50 |
| 2026-02-11 00:00 |
10:09:59.70 |
+29:44:50.3 |
HIP 49947 |
29.24 |
| 2026-02-11 12:00 |
10:09:43.09 |
+29:46:12.0 |
HIP 49947 |
33.01 |
| 2026-02-12 00:00 |
10:09:26.46 |
+29:47:33.2 |
HIP 49565 |
34.38 |
| 2026-02-12 12:00 |
10:09:09.82 |
+29:48:53.9 |
HIP 49565 |
32.02 |
| 2026-02-13 00:00 |
10:08:53.16 |
+29:50:13.9 |
HIP 49565 |
29.95 |
| 2026-02-13 12:00 |
10:08:36.48 |
+29:51:33.4 |
HIP 49565 |
28.26 |
| 2026-02-14 00:00 |
10:08:19.80 |
+29:52:52.3 |
HIP 49565 |
27.01 |
| 2026-02-14 12:00 |
10:08:03.10 |
+29:54:10.7 |
HIP 49565 |
26.26 |
| 2026-02-15 00:00 |
10:07:46.39 |
+29:55:28.5 |
HIP 49565 |
26.06 |
| 2026-02-15 12:00 |
10:07:29.67 |
+29:56:45.6 |
HIP 49565 |
26.41 |
| 2026-02-16 00:00 |
10:07:12.95 |
+29:58:02.2 |
HIP 49565 |
27.29 |
| 2026-02-16 12:00 |
10:06:56.22 |
+29:59:18.1 |
HIP 49398 |
27.96 |
| 2026-02-17 00:00 |
10:06:39.49 |
+30:00:33.5 |
HIP 49398 |
25.66 |
| 2026-02-17 12:00 |
10:06:22.75 |
+30:01:48.2 |
HIP 49398 |
23.75 |
| 2026-02-18 00:00 |
10:06:06.02 |
+30:03:02.3 |
HIP 49398 |
22.33 |
| 2026-02-18 12:00 |
10:05:49.28 |
+30:04:15.8 |
HIP 49398 |
21.51 |
| 2026-02-19 00:00 |
10:05:32.55 |
+30:05:28.6 |
HIP 49398 |
21.33 |
| 2026-02-19 12:00 |
10:05:15.82 |
+30:06:40.8 |
HIP 49398 |
21.83 |
| 2026-02-20 00:00 |
10:04:59.09 |
+30:07:52.3 |
HIP 49398 |
22.95 |
| 2026-02-20 12:00 |
10:04:42.37 |
+30:09:03.2 |
HIP 49398 |
24.61 |
| 2026-02-21 00:00 |
10:04:25.66 |
+30:10:13.4 |
HIP 49398 |
26.69 |
| 2026-02-21 12:00 |
10:04:08.96 |
+30:11:23.0 |
HIP 49398 |
29.12 |
| 2026-02-22 00:00 |
10:03:52.27 |
+30:12:31.9 |
HIP 49398 |
31.81 |
| 2026-02-22 12:00 |
10:03:35.59 |
+30:13:40.1 |
HIP 49398 |
34.69 |
| 2026-02-23 00:00 |
10:03:18.92 |
+30:14:47.6 |
HIP 49113 |
31.98 |
| 2026-02-23 12:00 |
10:03:02.27 |
+30:15:54.5 |
HIP 49113 |
28.54 |
| 2026-02-24 00:00 |
10:02:45.64 |
+30:17:00.7 |
HIP 49113 |
25.20 |