| Parameter |
Value |
| Designation |
P/2021 U3 (Attard-Maury) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-10-24T20:33:36.668160Z |
| Orbit solution date (soln_date, UTC) |
2022-06-07T21:45:23Z |
| Obs used |
275 |
| NEO |
- |
| M1 |
16.800 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-10-24T07:31:22.080000Z |
| Discovery magnitude (MPC) |
19.20 G |
| Discovery observatory (MPC) |
W94 · MAPS, San Pedro de Atacama |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-11-24.0000000 |
| e |
0.54990855 |
| q (au) |
1.886801 |
| a (au) |
4.192038 |
| i (deg) |
69.962967 |
| Ω (om, deg) |
75.113082 |
| ω (w, deg) |
335.208488 |
| M (ma, deg) |
3.461445 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.431 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.431 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.746 |
| k |
0.988 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
16:49:28.97 |
+00:46:30.7 |
HIP 82334 |
6.98 |
| 2026-05-12 12:00 |
16:49:11.13 |
+00:46:30.3 |
HIP 82334 |
7.82 |
| 2026-05-13 00:00 |
16:48:53.20 |
+00:46:29.2 |
HIP 82334 |
10.68 |
| 2026-05-13 12:00 |
16:48:35.19 |
+00:46:27.1 |
HIP 82334 |
14.41 |
| 2026-05-14 00:00 |
16:48:17.09 |
+00:46:24.2 |
HIP 82334 |
18.52 |
| 2026-05-14 12:00 |
16:47:58.91 |
+00:46:20.4 |
HIP 82247 |
19.45 |
| 2026-05-15 00:00 |
16:47:40.66 |
+00:46:15.7 |
HIP 82146 |
20.63 |
| 2026-05-15 12:00 |
16:47:22.33 |
+00:46:10.1 |
HIP 82146 |
18.37 |
| 2026-05-16 00:00 |
16:47:03.92 |
+00:46:03.5 |
HIP 82146 |
17.04 |
| 2026-05-16 12:00 |
16:46:45.44 |
+00:45:56.1 |
HIP 82146 |
16.89 |
| 2026-05-17 00:00 |
16:46:26.89 |
+00:45:47.7 |
HIP 82146 |
17.97 |
| 2026-05-17 12:00 |
16:46:08.28 |
+00:45:38.4 |
HIP 82037 |
18.32 |
| 2026-05-18 00:00 |
16:45:49.59 |
+00:45:28.2 |
HIP 82037 |
16.51 |
| 2026-05-18 12:00 |
16:45:30.85 |
+00:45:17.0 |
HIP 82037 |
15.93 |
| 2026-05-19 00:00 |
16:45:12.04 |
+00:45:04.9 |
HIP 82037 |
16.72 |
| 2026-05-19 12:00 |
16:44:53.17 |
+00:44:51.8 |
HIP 82037 |
18.72 |
| 2026-05-20 00:00 |
16:44:34.25 |
+00:44:37.8 |
HIP 82037 |
21.61 |
| 2026-05-20 12:00 |
16:44:15.27 |
+00:44:22.8 |
HIP 82037 |
25.08 |
| 2026-05-21 00:00 |
16:43:56.24 |
+00:44:06.9 |
HIP 82037 |
28.94 |
| 2026-05-21 12:00 |
16:43:37.15 |
+00:43:49.9 |
HIP 82037 |
33.06 |
| 2026-05-22 00:00 |
16:43:18.02 |
+00:43:32.0 |
HIP 81703 |
32.07 |
| 2026-05-22 12:00 |
16:42:58.85 |
+00:43:13.2 |
HIP 81703 |
27.62 |
| 2026-05-23 00:00 |
16:42:39.63 |
+00:42:53.3 |
HIP 81703 |
23.29 |
| 2026-05-23 12:00 |
16:42:20.37 |
+00:42:32.4 |
HIP 81703 |
19.17 |
| 2026-05-24 00:00 |
16:42:01.07 |
+00:42:10.6 |
HIP 81703 |
15.44 |
| 2026-05-24 12:00 |
16:41:41.74 |
+00:41:47.8 |
HIP 81703 |
12.48 |
| 2026-05-25 00:00 |
16:41:22.37 |
+00:41:24.0 |
HIP 81703 |
10.95 |
| 2026-05-25 12:00 |
16:41:02.96 |
+00:40:59.1 |
HIP 81703 |
11.44 |
| 2026-05-26 00:00 |
16:40:43.53 |
+00:40:33.3 |
HIP 81703 |
13.76 |
| 2026-05-26 12:00 |
16:40:24.07 |
+00:40:06.5 |
HIP 81703 |
17.17 |
| 2026-05-27 00:00 |
16:40:04.58 |
+00:39:38.7 |
HIP 81503 |
19.11 |
| 2026-05-27 12:00 |
16:39:45.07 |
+00:39:09.9 |
HIP 81503 |
14.56 |
| 2026-05-28 00:00 |
16:39:25.54 |
+00:38:40.0 |
HIP 81503 |
10.35 |
| 2026-05-28 12:00 |
16:39:05.99 |
+00:38:09.2 |
HIP 81503 |
7.12 |
| 2026-05-29 00:00 |
16:38:46.42 |
+00:37:37.3 |
HIP 81503 |
6.53 |
| 2026-05-29 12:00 |
16:38:26.83 |
+00:37:04.4 |
HIP 81503 |
9.13 |
| 2026-05-30 00:00 |
16:38:07.24 |
+00:36:30.5 |
HIP 81503 |
13.15 |
| 2026-05-30 12:00 |
16:37:47.63 |
+00:35:55.6 |
HIP 81503 |
17.65 |
| 2026-05-31 00:00 |
16:37:28.01 |
+00:35:19.7 |
HIP 81375 |
20.67 |
| 2026-05-31 12:00 |
16:37:08.39 |
+00:34:42.8 |
HIP 81375 |
19.46 |
| 2026-06-01 00:00 |
16:36:48.76 |
+00:34:04.8 |
HIP 81375 |
19.46 |
| 2026-06-01 12:00 |
16:36:29.13 |
+00:33:25.8 |
HIP 81375 |
20.66 |
| 2026-06-02 00:00 |
16:36:09.50 |
+00:32:45.8 |
HIP 81192 |
22.06 |