C/2020 F8 (SWAN)
| Parameter |
Value |
| Designation |
C/2020 F8 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-05-27T13:06:40.423680Z |
| Orbit solution date (soln_date, UTC) |
2025-01-13T11:42:04Z |
| Obs used |
376 |
| NEO |
- |
| M1 |
11.600 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-04-24.0000000 |
| e |
0.99984071 |
| q (au) |
0.430317 |
| a (au) |
2701.498705 |
| i (deg) |
110.796078 |
| Ω (om, deg) |
260.028658 |
| ω (w, deg) |
68.198142 |
| M (ma, deg) |
359.999765 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.818 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.818 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2019-10-22 |
2020-05-04 |
+12.2165 |
-0.587 |
| 2020-05-04 |
2020-05-26 |
-11.0290 |
-2.641 |
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 |
04:07:51.78 |
-26:26:09.1 |
HIP 19236 |
10.32 |
| 2026-02-03 12:00 |
04:07:49.14 |
-26:25:06.7 |
HIP 19236 |
9.14 |
| 2026-02-04 00:00 |
04:07:46.57 |
-26:24:04.0 |
HIP 19236 |
7.97 |
| 2026-02-04 12:00 |
04:07:44.07 |
-26:23:01.0 |
HIP 19236 |
6.81 |
| 2026-02-05 00:00 |
04:07:41.63 |
-26:21:57.8 |
HIP 19236 |
5.67 |
| 2026-02-05 12:00 |
04:07:39.26 |
-26:20:54.3 |
HIP 19236 |
4.57 |
| 2026-02-06 00:00 |
04:07:36.95 |
-26:19:50.6 |
HIP 19236 |
3.53 |
| 2026-02-06 12:00 |
04:07:34.71 |
-26:18:46.6 |
HIP 19236 |
2.62 |
| 2026-02-07 00:00 |
04:07:32.53 |
-26:17:42.4 |
HIP 19236 |
2.04 |
| 2026-02-07 12:00 |
04:07:30.42 |
-26:16:38.0 |
HIP 19236 |
2.06 |
| 2026-02-08 00:00 |
04:07:28.37 |
-26:15:33.3 |
HIP 19236 |
2.68 |
| 2026-02-08 12:00 |
04:07:26.40 |
-26:14:28.4 |
HIP 19236 |
3.58 |
| 2026-02-09 00:00 |
04:07:24.48 |
-26:13:23.3 |
HIP 19236 |
4.62 |
| 2026-02-09 12:00 |
04:07:22.64 |
-26:12:18.0 |
HIP 19236 |
5.70 |
| 2026-02-10 00:00 |
04:07:20.85 |
-26:11:12.5 |
HIP 19236 |
6.82 |
| 2026-02-10 12:00 |
04:07:19.14 |
-26:10:06.8 |
HIP 19236 |
7.95 |
| 2026-02-11 00:00 |
04:07:17.49 |
-26:09:00.9 |
HIP 19236 |
9.09 |
| 2026-02-11 12:00 |
04:07:15.91 |
-26:07:54.8 |
HIP 19236 |
10.23 |
| 2026-02-12 00:00 |
04:07:14.39 |
-26:06:48.5 |
HIP 19236 |
11.38 |
| 2026-02-12 12:00 |
04:07:12.94 |
-26:05:42.1 |
HIP 19236 |
12.52 |
| 2026-02-13 00:00 |
04:07:11.56 |
-26:04:35.5 |
HIP 19236 |
13.67 |
| 2026-02-13 12:00 |
04:07:10.24 |
-26:03:28.7 |
HIP 19236 |
14.82 |
| 2026-02-14 00:00 |
04:07:08.99 |
-26:02:21.8 |
HIP 19236 |
15.97 |
| 2026-02-14 12:00 |
04:07:07.80 |
-26:01:14.8 |
HIP 19236 |
17.12 |
| 2026-02-15 00:00 |
04:07:06.68 |
-26:00:07.6 |
HIP 19236 |
18.27 |
| 2026-02-15 12:00 |
04:07:05.63 |
-25:59:00.2 |
HIP 19236 |
19.42 |
| 2026-02-16 00:00 |
04:07:04.64 |
-25:57:52.7 |
HIP 19236 |
20.56 |
| 2026-02-16 12:00 |
04:07:03.72 |
-25:56:45.1 |
HIP 19236 |
21.71 |
| 2026-02-17 00:00 |
04:07:02.86 |
-25:55:37.4 |
HIP 19236 |
22.85 |
| 2026-02-17 12:00 |
04:07:02.07 |
-25:54:29.6 |
HIP 19236 |
24.00 |
| 2026-02-18 00:00 |
04:07:01.34 |
-25:53:21.6 |
HIP 19236 |
25.14 |
| 2026-02-18 12:00 |
04:07:00.68 |
-25:52:13.6 |
HIP 19236 |
26.28 |
| 2026-02-19 00:00 |
04:07:00.09 |
-25:51:05.5 |
HIP 19236 |
27.42 |
| 2026-02-19 12:00 |
04:06:59.56 |
-25:49:57.3 |
HIP 19236 |
28.56 |
| 2026-02-20 00:00 |
04:06:59.10 |
-25:48:49.0 |
HIP 19236 |
29.70 |
| 2026-02-20 12:00 |
04:06:58.70 |
-25:47:40.6 |
HIP 19297 |
29.28 |
| 2026-02-21 00:00 |
04:06:58.36 |
-25:46:32.1 |
HIP 19297 |
28.39 |
| 2026-02-21 12:00 |
04:06:58.10 |
-25:45:23.6 |
HIP 19297 |
27.51 |
| 2026-02-22 00:00 |
04:06:57.89 |
-25:44:15.1 |
HIP 19297 |
26.64 |
| 2026-02-22 12:00 |
04:06:57.75 |
-25:43:06.5 |
HIP 19297 |
25.79 |
| 2026-02-23 00:00 |
04:06:57.68 |
-25:41:57.8 |
HIP 19297 |
24.94 |
| 2026-02-23 12:00 |
04:06:57.67 |
-25:40:49.1 |
HIP 19297 |
24.11 |
| 2026-02-24 00:00 |
04:06:57.72 |
-25:39:40.4 |
HIP 19297 |
23.30 |