| Parameter |
Value |
| Designation |
C/2020 F2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-07-15T21:34:18.912000Z |
| Orbit solution date (soln_date, UTC) |
2026-03-07T14:42:52Z |
| Obs used |
1649 |
| NEO |
- |
| M1 |
6.300 |
| K1 |
7.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-04-08.0000000 |
| e |
1.00484187 |
| q (au) |
8.817057 |
| a (au) |
-1821.002957 |
| i (deg) |
163.583705 |
| Ω (om, deg) |
250.268049 |
| ω (w, deg) |
48.361233 |
| M (ma, deg) |
-0.001254 |
Magnitude
Scatter + Global Linear
$$
M_a = (-1.805 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-1.805 |
| n |
6.000 |
| gf |
0.903 |
| gb |
-0.928 |
| k |
1.000 |
| δ90 |
3.436 |
| 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 |
+9.9413 |
-9.588 |
| 2022-07-16 |
2025-11-20 |
+12.4304 |
-11.931 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
09:47:24.02 |
+31:00:50.3 |
HIP 47945 |
17.79 |
| 2026-03-26 12:00 |
09:47:10.64 |
+31:01:11.4 |
HIP 47945 |
15.21 |
| 2026-03-27 00:00 |
09:46:57.36 |
+31:01:31.7 |
HIP 47945 |
12.77 |
| 2026-03-27 12:00 |
09:46:44.15 |
+31:01:51.3 |
HIP 47945 |
10.58 |
| 2026-03-28 00:00 |
09:46:31.04 |
+31:02:10.1 |
HIP 47945 |
8.79 |
| 2026-03-28 12:00 |
09:46:18.01 |
+31:02:28.3 |
HIP 47945 |
7.67 |
| 2026-03-29 00:00 |
09:46:05.07 |
+31:02:45.8 |
HIP 47945 |
7.50 |
| 2026-03-29 12:00 |
09:45:52.22 |
+31:03:02.5 |
HIP 47945 |
8.31 |
| 2026-03-30 00:00 |
09:45:39.45 |
+31:03:18.5 |
HIP 47945 |
9.86 |
| 2026-03-30 12:00 |
09:45:26.78 |
+31:03:33.9 |
HIP 47945 |
11.83 |
| 2026-03-31 00:00 |
09:45:14.19 |
+31:03:48.5 |
HIP 47945 |
14.05 |
| 2026-03-31 12:00 |
09:45:01.70 |
+31:04:02.4 |
HIP 47945 |
16.40 |
| 2026-04-01 00:00 |
09:44:49.30 |
+31:04:15.7 |
HIP 47945 |
18.82 |
| 2026-04-01 12:00 |
09:44:36.99 |
+31:04:28.2 |
HIP 47945 |
21.29 |
| 2026-04-02 00:00 |
09:44:24.77 |
+31:04:40.1 |
HIP 47945 |
23.78 |
| 2026-04-02 12:00 |
09:44:12.65 |
+31:04:51.2 |
HIP 47945 |
26.27 |
| 2026-04-03 00:00 |
09:44:00.61 |
+31:05:01.7 |
HIP 47945 |
28.77 |
| 2026-04-03 12:00 |
09:43:48.68 |
+31:05:11.5 |
HIP 47544 |
30.79 |
| 2026-04-04 00:00 |
09:43:36.83 |
+31:05:20.7 |
HIP 47544 |
28.39 |
| 2026-04-04 12:00 |
09:43:25.09 |
+31:05:29.1 |
HIP 47544 |
26.05 |
| 2026-04-05 00:00 |
09:43:13.43 |
+31:05:36.9 |
HIP 47544 |
23.76 |
| 2026-04-05 12:00 |
09:43:01.88 |
+31:05:44.1 |
HIP 47544 |
21.54 |
| 2026-04-06 00:00 |
09:42:50.42 |
+31:05:50.5 |
HIP 47544 |
19.41 |
| 2026-04-06 12:00 |
09:42:39.05 |
+31:05:56.4 |
HIP 47544 |
17.38 |
| 2026-04-07 00:00 |
09:42:27.79 |
+31:06:01.5 |
HIP 47544 |
15.50 |
| 2026-04-07 12:00 |
09:42:16.62 |
+31:06:06.0 |
HIP 47544 |
13.80 |
| 2026-04-08 00:00 |
09:42:05.55 |
+31:06:09.9 |
HIP 47544 |
12.36 |
| 2026-04-08 12:00 |
09:41:54.58 |
+31:06:13.1 |
HIP 47544 |
11.25 |
| 2026-04-09 00:00 |
09:41:43.70 |
+31:06:15.7 |
HIP 47544 |
10.57 |
| 2026-04-09 12:00 |
09:41:32.93 |
+31:06:17.6 |
HIP 47544 |
10.39 |
| 2026-04-10 00:00 |
09:41:22.26 |
+31:06:18.9 |
HIP 47544 |
10.71 |
| 2026-04-10 12:00 |
09:41:11.69 |
+31:06:19.6 |
HIP 47544 |
11.49 |
| 2026-04-11 00:00 |
09:41:01.22 |
+31:06:19.7 |
HIP 47544 |
12.63 |
| 2026-04-11 12:00 |
09:40:50.85 |
+31:06:19.1 |
HIP 47544 |
14.03 |
| 2026-04-12 00:00 |
09:40:40.58 |
+31:06:17.9 |
HIP 47544 |
15.61 |
| 2026-04-12 12:00 |
09:40:30.41 |
+31:06:16.1 |
HIP 47544 |
17.31 |
| 2026-04-13 00:00 |
09:40:20.35 |
+31:06:13.7 |
HIP 47544 |
19.10 |
| 2026-04-13 12:00 |
09:40:10.38 |
+31:06:10.7 |
HIP 47544 |
20.94 |
| 2026-04-14 00:00 |
09:40:00.52 |
+31:06:07.1 |
HIP 47544 |
22.81 |
| 2026-04-14 12:00 |
09:39:50.77 |
+31:06:02.8 |
HIP 47544 |
24.71 |
| 2026-04-15 00:00 |
09:39:41.12 |
+31:05:58.0 |
HIP 47324 |
24.65 |
| 2026-04-15 12:00 |
09:39:31.57 |
+31:05:52.6 |
HIP 47324 |
23.47 |
| 2026-04-16 00:00 |
09:39:22.12 |
+31:05:46.6 |
HIP 47324 |
22.42 |