| 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) |
| 2026-05-12 00:00 |
01:25:20.76 |
-05:28:33.9 |
HIP 6654 |
26.86 |
| 2026-05-12 12:00 |
01:25:31.58 |
-05:27:49.1 |
HIP 6654 |
26.27 |
| 2026-05-13 00:00 |
01:25:42.37 |
-05:27:04.7 |
HIP 6654 |
25.97 |
| 2026-05-13 12:00 |
01:25:53.13 |
-05:26:20.9 |
HIP 6654 |
25.97 |
| 2026-05-14 00:00 |
01:26:03.86 |
-05:25:37.5 |
HIP 6654 |
26.28 |
| 2026-05-14 12:00 |
01:26:14.55 |
-05:24:54.6 |
HIP 6654 |
26.86 |
| 2026-05-15 00:00 |
01:26:25.21 |
-05:24:12.1 |
HIP 6654 |
27.72 |
| 2026-05-15 12:00 |
01:26:35.83 |
-05:23:30.2 |
HIP 6654 |
28.81 |
| 2026-05-16 00:00 |
01:26:46.42 |
-05:22:48.7 |
HIP 6654 |
30.11 |
| 2026-05-16 12:00 |
01:26:56.97 |
-05:22:07.7 |
HIP 6654 |
31.59 |
| 2026-05-17 00:00 |
01:27:07.48 |
-05:21:27.2 |
HIP 6654 |
33.22 |
| 2026-05-17 12:00 |
01:27:17.96 |
-05:20:47.2 |
HIP 6912 |
33.39 |
| 2026-05-18 00:00 |
01:27:28.40 |
-05:20:07.7 |
HIP 6912 |
31.88 |
| 2026-05-18 12:00 |
01:27:38.81 |
-05:19:28.7 |
HIP 6912 |
30.53 |
| 2026-05-19 00:00 |
01:27:49.17 |
-05:18:50.2 |
HIP 6912 |
29.37 |
| 2026-05-19 12:00 |
01:27:59.50 |
-05:18:12.2 |
HIP 6912 |
28.40 |
| 2026-05-20 00:00 |
01:28:09.79 |
-05:17:34.6 |
HIP 6912 |
27.64 |
| 2026-05-20 12:00 |
01:28:20.03 |
-05:16:57.6 |
HIP 6912 |
27.13 |
| 2026-05-21 00:00 |
01:28:30.24 |
-05:16:21.1 |
HIP 6912 |
26.85 |
| 2026-05-21 12:00 |
01:28:40.41 |
-05:15:45.1 |
HIP 6912 |
26.82 |
| 2026-05-22 00:00 |
01:28:50.53 |
-05:15:09.6 |
HIP 6984 |
25.90 |
| 2026-05-22 12:00 |
01:29:00.62 |
-05:14:34.6 |
HIP 6984 |
24.95 |
| 2026-05-23 00:00 |
01:29:10.66 |
-05:14:00.1 |
HIP 6984 |
24.24 |
| 2026-05-23 12:00 |
01:29:20.66 |
-05:13:26.1 |
HIP 6984 |
23.78 |
| 2026-05-24 00:00 |
01:29:30.61 |
-05:12:52.6 |
HIP 6984 |
23.58 |
| 2026-05-24 12:00 |
01:29:40.53 |
-05:12:19.6 |
HIP 6984 |
23.65 |
| 2026-05-25 00:00 |
01:29:50.40 |
-05:11:47.2 |
HIP 7059 |
22.36 |
| 2026-05-25 12:00 |
01:30:00.22 |
-05:11:15.2 |
HIP 7059 |
20.16 |
| 2026-05-26 00:00 |
01:30:10.01 |
-05:10:43.8 |
HIP 7059 |
18.06 |
| 2026-05-26 12:00 |
01:30:19.74 |
-05:10:12.9 |
HIP 7059 |
16.09 |
| 2026-05-27 00:00 |
01:30:29.44 |
-05:09:42.5 |
HIP 7059 |
14.28 |
| 2026-05-27 12:00 |
01:30:39.08 |
-05:09:12.6 |
HIP 7059 |
12.71 |
| 2026-05-28 00:00 |
01:30:48.68 |
-05:08:43.3 |
HIP 7059 |
11.47 |
| 2026-05-28 12:00 |
01:30:58.24 |
-05:08:14.4 |
HIP 7059 |
10.66 |
| 2026-05-29 00:00 |
01:31:07.74 |
-05:07:46.1 |
HIP 7059 |
10.38 |
| 2026-05-29 12:00 |
01:31:17.20 |
-05:07:18.3 |
HIP 7059 |
10.65 |
| 2026-05-30 00:00 |
01:31:26.62 |
-05:06:51.1 |
HIP 7124 |
10.66 |
| 2026-05-30 12:00 |
01:31:35.98 |
-05:06:24.3 |
HIP 7124 |
9.31 |
| 2026-05-31 00:00 |
01:31:45.30 |
-05:05:58.1 |
HIP 7124 |
8.44 |
| 2026-05-31 12:00 |
01:31:54.56 |
-05:05:32.4 |
HIP 7124 |
8.18 |
| 2026-06-01 00:00 |
01:32:03.78 |
-05:05:07.3 |
HIP 7124 |
8.59 |
| 2026-06-01 12:00 |
01:32:12.95 |
-05:04:42.6 |
HIP 7124 |
9.57 |
| 2026-06-02 00:00 |
01:32:22.07 |
-05:04:18.5 |
HIP 7124 |
10.95 |