| Parameter |
Value |
| Designation |
C/2020 Y3 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-12-03T11:39:47.134080Z |
| Orbit solution date (soln_date, UTC) |
2021-09-04T23:43:08Z |
| Obs used |
380 |
| NEO |
- |
| M1 |
13.900 |
| K1 |
8.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-12-28T15:19:02.899200Z |
| Discovery magnitude (MPC) |
18.49 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-02-25.0000000 |
| e |
0.98676697 |
| q (au) |
1.999243 |
| a (au) |
151.079720 |
| i (deg) |
83.097062 |
| Ω (om, deg) |
191.426774 |
| ω (w, deg) |
342.043610 |
| M (ma, deg) |
0.044326 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.627 + 3.107\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.627 |
| n |
3.107 |
| gf |
0.996 |
| gb |
-0.500 |
| k |
0.974 |
| δ90 |
9.985 |
| 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) |
| 2026-06-01 00:00 |
22:11:08.12 |
+52:38:16.7 |
HIP 109403 |
11.85 |
| 2026-06-01 12:00 |
22:11:07.24 |
+52:39:42.1 |
HIP 109403 |
12.15 |
| 2026-06-02 00:00 |
22:11:06.27 |
+52:41:07.3 |
HIP 109403 |
12.60 |
| 2026-06-02 12:00 |
22:11:05.20 |
+52:42:32.2 |
HIP 109403 |
13.17 |
| 2026-06-03 00:00 |
22:11:04.03 |
+52:43:56.8 |
HIP 109403 |
13.84 |
| 2026-06-03 12:00 |
22:11:02.77 |
+52:45:21.1 |
HIP 109403 |
14.62 |
| 2026-06-04 00:00 |
22:11:01.41 |
+52:46:45.1 |
HIP 109403 |
15.47 |
| 2026-06-04 12:00 |
22:10:59.95 |
+52:48:08.8 |
HIP 109403 |
16.38 |
| 2026-06-05 00:00 |
22:10:58.40 |
+52:49:32.2 |
HIP 109403 |
17.35 |
| 2026-06-05 12:00 |
22:10:56.75 |
+52:50:55.2 |
HIP 109403 |
18.36 |
| 2026-06-06 00:00 |
22:10:55.00 |
+52:52:18.0 |
HIP 109403 |
19.42 |
| 2026-06-06 12:00 |
22:10:53.16 |
+52:53:40.4 |
HIP 109679 |
19.74 |
| 2026-06-07 00:00 |
22:10:51.22 |
+52:55:02.4 |
HIP 109679 |
19.96 |
| 2026-06-07 12:00 |
22:10:49.19 |
+52:56:24.2 |
HIP 109679 |
20.29 |
| 2026-06-08 00:00 |
22:10:47.06 |
+52:57:45.5 |
HIP 109679 |
20.73 |
| 2026-06-08 12:00 |
22:10:44.83 |
+52:59:06.5 |
HIP 109679 |
21.26 |
| 2026-06-09 00:00 |
22:10:42.50 |
+53:00:27.2 |
HIP 109679 |
21.87 |
| 2026-06-09 12:00 |
22:10:40.08 |
+53:01:47.5 |
HIP 109679 |
22.57 |
| 2026-06-10 00:00 |
22:10:37.56 |
+53:03:07.3 |
HIP 109679 |
23.34 |
| 2026-06-10 12:00 |
22:10:34.95 |
+53:04:26.9 |
HIP 109679 |
24.18 |
| 2026-06-11 00:00 |
22:10:32.24 |
+53:05:46.0 |
HIP 109679 |
25.07 |
| 2026-06-11 12:00 |
22:10:29.43 |
+53:07:04.7 |
HIP 109679 |
26.02 |
| 2026-06-12 00:00 |
22:10:26.53 |
+53:08:23.0 |
HIP 109713 |
26.60 |
| 2026-06-12 12:00 |
22:10:23.53 |
+53:09:40.9 |
HIP 109713 |
27.04 |
| 2026-06-13 00:00 |
22:10:20.44 |
+53:10:58.3 |
HIP 109205 |
27.20 |
| 2026-06-13 12:00 |
22:10:17.25 |
+53:12:15.3 |
HIP 109205 |
26.41 |
| 2026-06-14 00:00 |
22:10:13.96 |
+53:13:31.9 |
HIP 109205 |
25.65 |
| 2026-06-14 12:00 |
22:10:10.58 |
+53:14:48.1 |
HIP 109205 |
24.93 |
| 2026-06-15 00:00 |
22:10:07.10 |
+53:16:03.8 |
HIP 109205 |
24.25 |
| 2026-06-15 12:00 |
22:10:03.53 |
+53:17:19.0 |
HIP 109205 |
23.62 |
| 2026-06-16 00:00 |
22:09:59.86 |
+53:18:33.8 |
HIP 109205 |
23.04 |
| 2026-06-16 12:00 |
22:09:56.10 |
+53:19:48.1 |
HIP 109205 |
22.52 |
| 2026-06-17 00:00 |
22:09:52.24 |
+53:21:01.9 |
HIP 109205 |
22.05 |
| 2026-06-17 12:00 |
22:09:48.29 |
+53:22:15.2 |
HIP 109205 |
21.64 |
| 2026-06-18 00:00 |
22:09:44.24 |
+53:23:28.0 |
HIP 109205 |
21.29 |
| 2026-06-18 12:00 |
22:09:40.11 |
+53:24:40.4 |
HIP 109205 |
21.01 |
| 2026-06-19 00:00 |
22:09:35.87 |
+53:25:52.2 |
HIP 109205 |
20.80 |
| 2026-06-19 12:00 |
22:09:31.55 |
+53:27:03.5 |
HIP 109205 |
20.66 |
| 2026-06-20 00:00 |
22:09:27.13 |
+53:28:14.3 |
HIP 109205 |
20.60 |
| 2026-06-20 12:00 |
22:09:22.62 |
+53:29:24.5 |
HIP 109205 |
20.60 |
| 2026-06-21 00:00 |
22:09:18.02 |
+53:30:34.3 |
HIP 109205 |
20.68 |
| 2026-06-21 12:00 |
22:09:13.33 |
+53:31:43.5 |
HIP 109205 |
20.83 |
| 2026-06-22 00:00 |
22:09:08.55 |
+53:32:52.1 |
HIP 109205 |
21.05 |