| 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) |
| 2026-07-29 00:00 |
16:07:01.75 |
-02:24:22.9 |
HIP 78902 |
13.44 |
| 2026-07-29 12:00 |
16:06:53.87 |
-02:26:37.1 |
HIP 78902 |
10.46 |
| 2026-07-30 00:00 |
16:06:46.15 |
-02:28:51.7 |
HIP 78902 |
7.52 |
| 2026-07-30 12:00 |
16:06:38.59 |
-02:31:06.7 |
HIP 78902 |
4.63 |
| 2026-07-31 00:00 |
16:06:31.18 |
-02:33:22.2 |
HIP 78902 |
1.92 |
| 2026-07-31 12:00 |
16:06:23.94 |
-02:35:38.1 |
HIP 78902 |
1.74 |
| 2026-08-01 00:00 |
16:06:16.86 |
-02:37:54.3 |
HIP 78902 |
4.36 |
| 2026-08-01 12:00 |
16:06:09.94 |
-02:40:11.0 |
HIP 78902 |
7.17 |
| 2026-08-02 00:00 |
16:06:03.18 |
-02:42:28.1 |
HIP 78902 |
9.99 |
| 2026-08-02 12:00 |
16:05:56.58 |
-02:44:45.6 |
HIP 78902 |
12.81 |
| 2026-08-03 00:00 |
16:05:50.14 |
-02:47:03.4 |
HIP 78902 |
15.61 |
| 2026-08-03 12:00 |
16:05:43.86 |
-02:49:21.6 |
HIP 78902 |
18.40 |
| 2026-08-04 00:00 |
16:05:37.74 |
-02:51:40.2 |
HIP 78902 |
21.17 |
| 2026-08-04 12:00 |
16:05:31.79 |
-02:53:59.2 |
HIP 78902 |
23.92 |
| 2026-08-05 00:00 |
16:05:25.99 |
-02:56:18.5 |
HIP 78725 |
24.07 |
| 2026-08-05 12:00 |
16:05:20.36 |
-02:58:38.2 |
HIP 78725 |
21.44 |
| 2026-08-06 00:00 |
16:05:14.88 |
-03:00:58.2 |
HIP 78725 |
18.88 |
| 2026-08-06 12:00 |
16:05:09.57 |
-03:03:18.5 |
HIP 78725 |
16.38 |
| 2026-08-07 00:00 |
16:05:04.42 |
-03:05:39.2 |
HIP 78725 |
13.99 |
| 2026-08-07 12:00 |
16:04:59.43 |
-03:08:00.2 |
HIP 78725 |
11.76 |
| 2026-08-08 00:00 |
16:04:54.61 |
-03:10:21.5 |
HIP 78725 |
9.77 |
| 2026-08-08 12:00 |
16:04:49.94 |
-03:12:43.2 |
HIP 78725 |
8.22 |
| 2026-08-09 00:00 |
16:04:45.44 |
-03:15:05.1 |
HIP 78725 |
7.35 |
| 2026-08-09 12:00 |
16:04:41.09 |
-03:17:27.3 |
HIP 78725 |
7.40 |
| 2026-08-10 00:00 |
16:04:36.91 |
-03:19:49.9 |
HIP 78725 |
8.33 |
| 2026-08-10 12:00 |
16:04:32.89 |
-03:22:12.7 |
HIP 78725 |
9.90 |
| 2026-08-11 00:00 |
16:04:29.03 |
-03:24:35.7 |
HIP 78725 |
11.85 |
| 2026-08-11 12:00 |
16:04:25.34 |
-03:26:59.1 |
HIP 78792 |
11.74 |
| 2026-08-12 00:00 |
16:04:21.80 |
-03:29:22.7 |
HIP 78792 |
11.87 |
| 2026-08-12 12:00 |
16:04:18.43 |
-03:31:46.6 |
HIP 78792 |
12.50 |
| 2026-08-13 00:00 |
16:04:15.21 |
-03:34:10.7 |
HIP 78792 |
13.53 |
| 2026-08-13 12:00 |
16:04:12.16 |
-03:36:35.1 |
HIP 78792 |
14.90 |
| 2026-08-14 00:00 |
16:04:09.27 |
-03:38:59.7 |
HIP 78792 |
16.50 |
| 2026-08-14 12:00 |
16:04:06.54 |
-03:41:24.5 |
HIP 78792 |
18.28 |
| 2026-08-15 00:00 |
16:04:03.97 |
-03:43:49.6 |
HIP 78792 |
20.18 |
| 2026-08-15 12:00 |
16:04:01.56 |
-03:46:14.8 |
HIP 78577 |
20.87 |
| 2026-08-16 00:00 |
16:03:59.30 |
-03:48:40.3 |
HIP 78577 |
21.27 |
| 2026-08-16 12:00 |
16:03:57.21 |
-03:51:06.0 |
HIP 78577 |
21.98 |
| 2026-08-17 00:00 |
16:03:55.28 |
-03:53:31.9 |
HIP 78577 |
22.97 |
| 2026-08-17 12:00 |
16:03:53.50 |
-03:55:57.9 |
HIP 78577 |
24.21 |
| 2026-08-18 00:00 |
16:03:51.88 |
-03:58:24.1 |
HIP 78577 |
25.66 |
| 2026-08-18 12:00 |
16:03:50.42 |
-04:00:50.5 |
HIP 78577 |
27.28 |
| 2026-08-19 00:00 |
16:03:49.12 |
-04:03:17.1 |
HIP 78577 |
29.04 |