| Parameter |
Value |
| Designation |
P/2021 J3 (ATLAS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2019-07-03T16:55:29.046720Z |
| Orbit solution date (soln_date, UTC) |
2024-03-19T12:13:27Z |
| Obs used |
145 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
10.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-05-13T13:05:15.216000Z |
| Discovery magnitude (MPC) |
18.64 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-07-10.0000000 |
| e |
0.45076663 |
| q (au) |
4.906343 |
| a (au) |
8.933076 |
| i (deg) |
14.570678 |
| Ω (om, deg) |
111.238530 |
| ω (w, deg) |
125.692921 |
| M (ma, deg) |
27.217217 |
Magnitude
Scatter + Global Linear
$$
M_a = (2.613 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
2.613 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.969 |
| k |
1.000 |
| δ90 |
10.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
01:07:06.08 |
-07:08:04.0 |
HIP 5326 |
22.88 |
| 2026-03-26 12:00 |
01:07:17.83 |
-07:06:46.0 |
HIP 5326 |
22.03 |
| 2026-03-27 00:00 |
01:07:29.60 |
-07:05:28.3 |
HIP 5326 |
21.62 |
| 2026-03-27 12:00 |
01:07:41.38 |
-07:04:10.7 |
HIP 5326 |
21.67 |
| 2026-03-28 00:00 |
01:07:53.17 |
-07:02:53.4 |
HIP 5326 |
22.18 |
| 2026-03-28 12:00 |
01:08:04.97 |
-07:01:36.3 |
HIP 5326 |
23.12 |
| 2026-03-29 00:00 |
01:08:16.78 |
-07:00:19.5 |
HIP 5443 |
22.90 |
| 2026-03-29 12:00 |
01:08:28.60 |
-06:59:02.9 |
HIP 5443 |
21.01 |
| 2026-03-30 00:00 |
01:08:40.44 |
-06:57:46.5 |
HIP 5443 |
19.48 |
| 2026-03-30 12:00 |
01:08:52.27 |
-06:56:30.4 |
HIP 5443 |
18.36 |
| 2026-03-31 00:00 |
01:09:04.12 |
-06:55:14.6 |
HIP 5443 |
17.76 |
| 2026-03-31 12:00 |
01:09:15.98 |
-06:53:58.9 |
HIP 5443 |
17.72 |
| 2026-04-01 00:00 |
01:09:27.84 |
-06:52:43.6 |
HIP 5443 |
18.25 |
| 2026-04-01 12:00 |
01:09:39.71 |
-06:51:28.5 |
HIP 5443 |
19.29 |
| 2026-04-02 00:00 |
01:09:51.59 |
-06:50:13.6 |
HIP 5443 |
20.78 |
| 2026-04-02 12:00 |
01:10:03.47 |
-06:48:59.0 |
HIP 5443 |
22.62 |
| 2026-04-03 00:00 |
01:10:15.36 |
-06:47:44.7 |
HIP 5443 |
24.73 |
| 2026-04-03 12:00 |
01:10:27.26 |
-06:46:30.7 |
HIP 5443 |
27.06 |
| 2026-04-04 00:00 |
01:10:39.16 |
-06:45:16.9 |
HIP 5443 |
29.55 |
| 2026-04-04 12:00 |
01:10:51.06 |
-06:44:03.4 |
HIP 5666 |
29.12 |
| 2026-04-05 00:00 |
01:11:02.97 |
-06:42:50.1 |
HIP 5666 |
26.34 |
| 2026-04-05 12:00 |
01:11:14.88 |
-06:41:37.1 |
HIP 5666 |
23.67 |
| 2026-04-06 00:00 |
01:11:26.79 |
-06:40:24.5 |
HIP 5666 |
21.15 |
| 2026-04-06 12:00 |
01:11:38.71 |
-06:39:12.1 |
HIP 5666 |
18.83 |
| 2026-04-07 00:00 |
01:11:50.63 |
-06:38:00.0 |
HIP 5666 |
16.79 |
| 2026-04-07 12:00 |
01:12:02.55 |
-06:36:48.1 |
HIP 5666 |
15.16 |
| 2026-04-08 00:00 |
01:12:14.47 |
-06:35:36.6 |
HIP 5666 |
14.07 |
| 2026-04-08 12:00 |
01:12:26.39 |
-06:34:25.3 |
HIP 5666 |
13.65 |
| 2026-04-09 00:00 |
01:12:38.31 |
-06:33:14.4 |
HIP 5666 |
13.96 |
| 2026-04-09 12:00 |
01:12:50.24 |
-06:32:03.8 |
HIP 5666 |
14.95 |
| 2026-04-10 00:00 |
01:13:02.16 |
-06:30:53.4 |
HIP 5666 |
16.50 |
| 2026-04-10 12:00 |
01:13:14.08 |
-06:29:43.4 |
HIP 5666 |
18.47 |
| 2026-04-11 00:00 |
01:13:26.00 |
-06:28:33.7 |
HIP 5666 |
20.74 |
| 2026-04-11 12:00 |
01:13:37.91 |
-06:27:24.3 |
HIP 5666 |
23.22 |
| 2026-04-12 00:00 |
01:13:49.83 |
-06:26:15.2 |
HIP 5666 |
25.85 |
| 2026-04-12 12:00 |
01:14:01.74 |
-06:25:06.4 |
HIP 5666 |
28.58 |
| 2026-04-13 00:00 |
01:14:13.64 |
-06:23:58.0 |
HIP 5918 |
29.85 |
| 2026-04-13 12:00 |
01:14:25.55 |
-06:22:49.8 |
HIP 5918 |
27.43 |
| 2026-04-14 00:00 |
01:14:37.44 |
-06:21:42.0 |
HIP 5918 |
25.18 |
| 2026-04-14 12:00 |
01:14:49.34 |
-06:20:34.6 |
HIP 5918 |
23.14 |
| 2026-04-15 00:00 |
01:15:01.22 |
-06:19:27.4 |
HIP 5918 |
21.38 |
| 2026-04-15 12:00 |
01:15:13.10 |
-06:18:20.7 |
HIP 5918 |
19.96 |
| 2026-04-16 00:00 |
01:15:24.98 |
-06:17:14.2 |
HIP 5918 |
18.95 |