| Parameter |
Value |
| Designation |
C/2020 X2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-11-15T21:24:26.968320Z |
| Orbit solution date (soln_date, UTC) |
2024-01-04T23:42:39Z |
| Obs used |
253 |
| NEO |
- |
| M1 |
7.000 |
| K1 |
16.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-12-10T12:05:53.462400Z |
| Discovery magnitude (MPC) |
18.27 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-12-19.0000000 |
| e |
0.76624465 |
| q (au) |
3.828504 |
| a (au) |
16.378251 |
| i (deg) |
18.191452 |
| Ω (om, deg) |
105.458856 |
| ω (w, deg) |
347.357421 |
| M (ma, deg) |
0.492307 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.671 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.671 |
| n |
6.000 |
| gf |
0.993 |
| gb |
-0.845 |
| k |
0.998 |
| δ90 |
1.012 |
| 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) |
| 2026-09-20 00:00 |
14:46:40.89 |
+00:08:14.4 |
HIP 72339 |
28.26 |
| 2026-09-20 12:00 |
14:46:48.29 |
+00:07:11.5 |
HIP 72339 |
26.51 |
| 2026-09-21 00:00 |
14:46:55.73 |
+00:06:08.5 |
HIP 72339 |
24.81 |
| 2026-09-21 12:00 |
14:47:03.22 |
+00:05:05.7 |
HIP 72339 |
23.17 |
| 2026-09-22 00:00 |
14:47:10.75 |
+00:04:02.8 |
HIP 72339 |
21.63 |
| 2026-09-22 12:00 |
14:47:18.32 |
+00:03:00.1 |
HIP 72339 |
20.20 |
| 2026-09-23 00:00 |
14:47:25.93 |
+00:01:57.4 |
HIP 72339 |
18.90 |
| 2026-09-23 12:00 |
14:47:33.58 |
+00:00:54.7 |
HIP 72339 |
17.78 |
| 2026-09-24 00:00 |
14:47:41.28 |
-00:00:07.8 |
HIP 72339 |
16.87 |
| 2026-09-24 12:00 |
14:47:49.01 |
-00:01:10.3 |
HIP 72339 |
16.21 |
| 2026-09-25 00:00 |
14:47:56.79 |
-00:02:12.7 |
HIP 72339 |
15.83 |
| 2026-09-25 12:00 |
14:48:04.60 |
-00:03:15.1 |
HIP 72339 |
15.77 |
| 2026-09-26 00:00 |
14:48:12.46 |
-00:04:17.4 |
HIP 72339 |
16.02 |
| 2026-09-26 12:00 |
14:48:20.35 |
-00:05:19.5 |
HIP 72339 |
16.57 |
| 2026-09-27 00:00 |
14:48:28.28 |
-00:06:21.7 |
HIP 72339 |
17.40 |
| 2026-09-27 12:00 |
14:48:36.25 |
-00:07:23.7 |
HIP 72339 |
18.48 |
| 2026-09-28 00:00 |
14:48:44.26 |
-00:08:25.6 |
HIP 72339 |
19.76 |
| 2026-09-28 12:00 |
14:48:52.31 |
-00:09:27.5 |
HIP 72339 |
21.21 |
| 2026-09-29 00:00 |
14:49:00.39 |
-00:10:29.2 |
HIP 72339 |
22.81 |
| 2026-09-29 12:00 |
14:49:08.51 |
-00:11:30.9 |
HIP 72590 |
23.42 |
| 2026-09-30 00:00 |
14:49:16.67 |
-00:12:32.4 |
HIP 72590 |
22.10 |
| 2026-09-30 12:00 |
14:49:24.86 |
-00:13:33.9 |
HIP 72590 |
20.93 |
| 2026-10-01 00:00 |
14:49:33.09 |
-00:14:35.2 |
HIP 72590 |
19.94 |
| 2026-10-01 12:00 |
14:49:41.35 |
-00:15:36.5 |
HIP 72590 |
19.18 |
| 2026-10-02 00:00 |
14:49:49.65 |
-00:16:37.6 |
HIP 72629 |
17.65 |
| 2026-10-02 12:00 |
14:49:57.98 |
-00:17:38.6 |
HIP 72629 |
15.69 |
| 2026-10-03 00:00 |
14:50:06.35 |
-00:18:39.5 |
HIP 72629 |
13.82 |
| 2026-10-03 12:00 |
14:50:14.75 |
-00:19:40.3 |
HIP 72629 |
12.10 |
| 2026-10-04 00:00 |
14:50:23.19 |
-00:20:41.0 |
HIP 72629 |
10.61 |
| 2026-10-04 12:00 |
14:50:31.66 |
-00:21:41.5 |
HIP 72629 |
9.46 |
| 2026-10-05 00:00 |
14:50:40.16 |
-00:22:42.0 |
HIP 72629 |
8.80 |
| 2026-10-05 12:00 |
14:50:48.69 |
-00:23:42.2 |
HIP 72629 |
8.73 |
| 2026-10-06 00:00 |
14:50:57.26 |
-00:24:42.4 |
HIP 72629 |
9.28 |
| 2026-10-06 12:00 |
14:51:05.85 |
-00:25:42.4 |
HIP 72629 |
10.36 |
| 2026-10-07 00:00 |
14:51:14.48 |
-00:26:42.3 |
HIP 72629 |
11.81 |
| 2026-10-07 12:00 |
14:51:23.14 |
-00:27:42.0 |
HIP 72629 |
13.54 |
| 2026-10-08 00:00 |
14:51:31.83 |
-00:28:41.6 |
HIP 72629 |
15.44 |
| 2026-10-08 12:00 |
14:51:40.55 |
-00:29:41.1 |
HIP 72776 |
15.89 |
| 2026-10-09 00:00 |
14:51:49.30 |
-00:30:40.4 |
HIP 72776 |
13.50 |
| 2026-10-09 12:00 |
14:51:58.07 |
-00:31:39.5 |
HIP 72776 |
11.12 |
| 2026-10-10 00:00 |
14:52:06.88 |
-00:32:38.5 |
HIP 72776 |
8.73 |
| 2026-10-10 12:00 |
14:52:15.71 |
-00:33:37.3 |
HIP 72776 |
6.36 |
| 2026-10-11 00:00 |
14:52:24.57 |
-00:34:36.0 |
HIP 72776 |
4.05 |