C/2021 J1 (Maury-Attard)
| Parameter |
Value |
| Designation |
C/2021 J1 (Maury-Attard) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-02-19T11:39:16.738560Z |
| Orbit solution date (soln_date, UTC) |
2022-02-03T20:43:07Z |
| Obs used |
106 |
| NEO |
- |
| M1 |
17.100 |
| K1 |
5.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-04-27.0000000 |
| e |
0.93438376 |
| q (au) |
1.740634 |
| a (au) |
26.527482 |
| i (deg) |
92.719322 |
| Ω (om, deg) |
88.320215 |
| ω (w, deg) |
147.329778 |
| M (ma, deg) |
0.479817 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.232 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.232 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.998 |
| 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) |
| 2026-02-03 00:00 |
05:54:32.65 |
-48:06:00.0 |
HIP 27866 |
7.74 |
| 2026-02-03 12:00 |
05:54:23.35 |
-48:04:11.4 |
HIP 27866 |
6.59 |
| 2026-02-04 00:00 |
05:54:14.15 |
-48:02:22.2 |
HIP 27866 |
6.21 |
| 2026-02-04 12:00 |
05:54:05.05 |
-48:00:32.2 |
HIP 27866 |
6.72 |
| 2026-02-05 00:00 |
05:53:56.05 |
-47:58:41.5 |
HIP 27818 |
7.90 |
| 2026-02-05 12:00 |
05:53:47.15 |
-47:56:50.1 |
HIP 27818 |
6.31 |
| 2026-02-06 00:00 |
05:53:38.36 |
-47:54:58.0 |
HIP 27818 |
5.36 |
| 2026-02-06 12:00 |
05:53:29.66 |
-47:53:05.2 |
HIP 27818 |
5.40 |
| 2026-02-07 00:00 |
05:53:21.07 |
-47:51:11.7 |
HIP 27818 |
6.42 |
| 2026-02-07 12:00 |
05:53:12.58 |
-47:49:17.5 |
HIP 27818 |
8.04 |
| 2026-02-08 00:00 |
05:53:04.20 |
-47:47:22.6 |
HIP 27756 |
7.90 |
| 2026-02-08 12:00 |
05:52:55.92 |
-47:45:27.1 |
HIP 27756 |
8.43 |
| 2026-02-09 00:00 |
05:52:47.75 |
-47:43:30.9 |
HIP 27756 |
9.56 |
| 2026-02-09 12:00 |
05:52:39.68 |
-47:41:34.1 |
HIP 27756 |
11.10 |
| 2026-02-10 00:00 |
05:52:31.72 |
-47:39:36.6 |
HIP 27756 |
12.91 |
| 2026-02-10 12:00 |
05:52:23.86 |
-47:37:38.5 |
HIP 27756 |
14.89 |
| 2026-02-11 00:00 |
05:52:16.11 |
-47:35:39.8 |
HIP 27756 |
16.97 |
| 2026-02-11 12:00 |
05:52:08.47 |
-47:33:40.5 |
HIP 27756 |
19.13 |
| 2026-02-12 00:00 |
05:52:00.93 |
-47:31:40.6 |
HIP 27756 |
21.34 |
| 2026-02-12 12:00 |
05:51:53.50 |
-47:29:40.1 |
HIP 27756 |
23.58 |
| 2026-02-13 00:00 |
05:51:46.18 |
-47:27:39.1 |
HIP 27756 |
25.86 |
| 2026-02-13 12:00 |
05:51:38.97 |
-47:25:37.4 |
HIP 27756 |
28.15 |
| 2026-02-14 00:00 |
05:51:31.87 |
-47:23:35.3 |
HIP 27898 |
29.91 |
| 2026-02-14 12:00 |
05:51:24.88 |
-47:21:32.5 |
HIP 27898 |
30.24 |
| 2026-02-15 00:00 |
05:51:18.00 |
-47:19:29.3 |
HIP 27898 |
30.73 |
| 2026-02-15 12:00 |
05:51:11.23 |
-47:17:25.5 |
HIP 27898 |
31.36 |
| 2026-02-16 00:00 |
05:51:04.57 |
-47:15:21.3 |
HIP 27898 |
32.15 |
| 2026-02-16 12:00 |
05:50:58.02 |
-47:13:16.5 |
HIP 27898 |
33.06 |
| 2026-02-17 00:00 |
05:50:51.58 |
-47:11:11.2 |
HIP 27898 |
34.10 |
| 2026-02-17 12:00 |
05:50:45.25 |
-47:09:05.5 |
HIP 27898 |
35.24 |
| 2026-02-18 00:00 |
05:50:39.03 |
-47:06:59.2 |
HIP 27898 |
36.49 |
| 2026-02-18 12:00 |
05:50:32.93 |
-47:04:52.6 |
HIP 27898 |
37.82 |
| 2026-02-19 00:00 |
05:50:26.93 |
-47:02:45.5 |
HIP 27898 |
39.24 |
| 2026-02-19 12:00 |
05:50:21.05 |
-47:00:37.9 |
HIP 27898 |
40.72 |
| 2026-02-20 00:00 |
05:50:15.28 |
-46:58:29.9 |
HIP 27650 |
39.11 |
| 2026-02-20 12:00 |
05:50:09.63 |
-46:56:21.6 |
HIP 27650 |
37.32 |
| 2026-02-21 00:00 |
05:50:04.08 |
-46:54:12.8 |
HIP 27650 |
35.59 |
| 2026-02-21 12:00 |
05:49:58.65 |
-46:52:03.6 |
HIP 27650 |
33.92 |
| 2026-02-22 00:00 |
05:49:53.34 |
-46:49:54.1 |
HIP 27650 |
32.32 |
| 2026-02-22 12:00 |
05:49:48.13 |
-46:47:44.1 |
HIP 27462 |
30.18 |
| 2026-02-23 00:00 |
05:49:43.04 |
-46:45:33.9 |
HIP 27462 |
27.85 |
| 2026-02-23 12:00 |
05:49:38.06 |
-46:43:23.3 |
HIP 27462 |
25.52 |
| 2026-02-24 00:00 |
05:49:33.19 |
-46:41:12.3 |
HIP 27462 |
23.19 |