| 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) |
| 2026-09-20 00:00 |
16:07:30.07 |
-06:41:17.9 |
HIP 79174 |
30.39 |
| 2026-09-20 12:00 |
16:07:37.89 |
-06:43:44.1 |
HIP 79174 |
28.36 |
| 2026-09-21 00:00 |
16:07:45.82 |
-06:46:10.3 |
HIP 79174 |
26.50 |
| 2026-09-21 12:00 |
16:07:53.87 |
-06:48:36.2 |
HIP 79174 |
24.88 |
| 2026-09-22 00:00 |
16:08:02.05 |
-06:51:02.0 |
HIP 79174 |
23.54 |
| 2026-09-22 12:00 |
16:08:10.34 |
-06:53:27.7 |
HIP 79174 |
22.54 |
| 2026-09-23 00:00 |
16:08:18.74 |
-06:55:53.2 |
HIP 79174 |
21.93 |
| 2026-09-23 12:00 |
16:08:27.26 |
-06:58:18.5 |
HIP 79174 |
21.76 |
| 2026-09-24 00:00 |
16:08:35.90 |
-07:00:43.6 |
HIP 79174 |
22.04 |
| 2026-09-24 12:00 |
16:08:44.65 |
-07:03:08.5 |
HIP 79174 |
22.76 |
| 2026-09-25 00:00 |
16:08:53.52 |
-07:05:33.3 |
HIP 79174 |
23.89 |
| 2026-09-25 12:00 |
16:09:02.50 |
-07:07:57.9 |
HIP 79174 |
25.39 |
| 2026-09-26 00:00 |
16:09:11.59 |
-07:10:22.3 |
HIP 79174 |
27.19 |
| 2026-09-26 12:00 |
16:09:20.79 |
-07:12:46.5 |
HIP 79174 |
29.25 |
| 2026-09-27 00:00 |
16:09:30.10 |
-07:15:10.5 |
HIP 79313 |
27.90 |
| 2026-09-27 12:00 |
16:09:39.53 |
-07:17:34.3 |
HIP 79313 |
24.80 |
| 2026-09-28 00:00 |
16:09:49.06 |
-07:19:57.9 |
HIP 79313 |
21.76 |
| 2026-09-28 12:00 |
16:09:58.71 |
-07:22:21.4 |
HIP 79313 |
18.79 |
| 2026-09-29 00:00 |
16:10:08.46 |
-07:24:44.6 |
HIP 79313 |
15.98 |
| 2026-09-29 12:00 |
16:10:18.32 |
-07:27:07.6 |
HIP 79313 |
13.40 |
| 2026-09-30 00:00 |
16:10:28.28 |
-07:29:30.4 |
HIP 79313 |
11.25 |
| 2026-09-30 12:00 |
16:10:38.36 |
-07:31:53.0 |
HIP 79313 |
9.84 |
| 2026-10-01 00:00 |
16:10:48.53 |
-07:34:15.3 |
HIP 79313 |
9.51 |
| 2026-10-01 12:00 |
16:10:58.82 |
-07:36:37.5 |
HIP 79313 |
10.38 |
| 2026-10-02 00:00 |
16:11:09.21 |
-07:38:59.4 |
HIP 79313 |
12.21 |
| 2026-10-02 12:00 |
16:11:19.70 |
-07:41:21.1 |
HIP 79313 |
14.66 |
| 2026-10-03 00:00 |
16:11:30.30 |
-07:43:42.6 |
HIP 79313 |
17.48 |
| 2026-10-03 12:00 |
16:11:41.00 |
-07:46:03.9 |
HIP 79313 |
20.52 |
| 2026-10-04 00:00 |
16:11:51.80 |
-07:48:24.9 |
HIP 79313 |
23.72 |
| 2026-10-04 12:00 |
16:12:02.70 |
-07:50:45.7 |
HIP 79313 |
27.01 |
| 2026-10-05 00:00 |
16:12:13.71 |
-07:53:06.3 |
HIP 79529 |
26.67 |
| 2026-10-05 12:00 |
16:12:24.81 |
-07:55:26.6 |
HIP 79529 |
23.11 |
| 2026-10-06 00:00 |
16:12:36.02 |
-07:57:46.6 |
HIP 79529 |
19.55 |
| 2026-10-06 12:00 |
16:12:47.32 |
-08:00:06.4 |
HIP 79529 |
15.99 |
| 2026-10-07 00:00 |
16:12:58.72 |
-08:02:26.0 |
HIP 79529 |
12.47 |
| 2026-10-07 12:00 |
16:13:10.22 |
-08:04:45.3 |
HIP 79529 |
9.03 |
| 2026-10-08 00:00 |
16:13:21.82 |
-08:07:04.4 |
HIP 79529 |
5.85 |
| 2026-10-08 12:00 |
16:13:33.51 |
-08:09:23.2 |
HIP 79529 |
3.75 |
| 2026-10-09 00:00 |
16:13:45.30 |
-08:11:41.7 |
HIP 79529 |
4.62 |
| 2026-10-09 12:00 |
16:13:57.18 |
-08:14:00.0 |
HIP 79529 |
7.50 |
| 2026-10-10 00:00 |
16:14:09.16 |
-08:16:17.9 |
HIP 79529 |
10.93 |
| 2026-10-10 12:00 |
16:14:21.23 |
-08:18:35.6 |
HIP 79529 |
14.52 |
| 2026-10-11 00:00 |
16:14:33.39 |
-08:20:53.1 |
HIP 79672 |
15.81 |