| 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 |
-0.512 |
| 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) |
| 2026-09-20 00:00 |
06:31:09.71 |
-42:47:31.8 |
HIP 31163 |
19.10 |
| 2026-09-20 12:00 |
06:31:11.05 |
-42:49:04.6 |
HIP 31163 |
20.10 |
| 2026-09-21 00:00 |
06:31:12.31 |
-42:50:37.6 |
HIP 31163 |
21.18 |
| 2026-09-21 12:00 |
06:31:13.47 |
-42:52:10.7 |
HIP 31163 |
22.33 |
| 2026-09-22 00:00 |
06:31:14.55 |
-42:53:44.0 |
HIP 31163 |
23.54 |
| 2026-09-22 12:00 |
06:31:15.53 |
-42:55:17.3 |
HIP 31163 |
24.79 |
| 2026-09-23 00:00 |
06:31:16.42 |
-42:56:50.8 |
HIP 31163 |
26.09 |
| 2026-09-23 12:00 |
06:31:17.23 |
-42:58:24.4 |
HIP 31163 |
27.43 |
| 2026-09-24 00:00 |
06:31:17.94 |
-42:59:58.0 |
HIP 31163 |
28.80 |
| 2026-09-24 12:00 |
06:31:18.57 |
-43:01:31.8 |
HIP 31163 |
30.19 |
| 2026-09-25 00:00 |
06:31:19.10 |
-43:03:05.7 |
HIP 31126 |
29.53 |
| 2026-09-25 12:00 |
06:31:19.54 |
-43:04:39.6 |
HIP 31126 |
27.98 |
| 2026-09-26 00:00 |
06:31:19.89 |
-43:06:13.6 |
HIP 31126 |
26.44 |
| 2026-09-26 12:00 |
06:31:20.15 |
-43:07:47.7 |
HIP 31126 |
24.90 |
| 2026-09-27 00:00 |
06:31:20.32 |
-43:09:21.8 |
HIP 31126 |
23.37 |
| 2026-09-27 12:00 |
06:31:20.39 |
-43:10:56.0 |
HIP 31126 |
21.84 |
| 2026-09-28 00:00 |
06:31:20.38 |
-43:12:30.2 |
HIP 31126 |
20.33 |
| 2026-09-28 12:00 |
06:31:20.27 |
-43:14:04.5 |
HIP 31126 |
18.83 |
| 2026-09-29 00:00 |
06:31:20.07 |
-43:15:38.8 |
HIP 31126 |
17.35 |
| 2026-09-29 12:00 |
06:31:19.77 |
-43:17:13.1 |
HIP 31126 |
15.89 |
| 2026-09-30 00:00 |
06:31:19.38 |
-43:18:47.4 |
HIP 31126 |
14.46 |
| 2026-09-30 12:00 |
06:31:18.90 |
-43:20:21.7 |
HIP 31126 |
13.08 |
| 2026-10-01 00:00 |
06:31:18.33 |
-43:21:56.0 |
HIP 31126 |
11.75 |
| 2026-10-01 12:00 |
06:31:17.66 |
-43:23:30.4 |
HIP 31126 |
10.49 |
| 2026-10-02 00:00 |
06:31:16.90 |
-43:25:04.7 |
HIP 31126 |
9.35 |
| 2026-10-02 12:00 |
06:31:16.04 |
-43:26:38.9 |
HIP 31126 |
8.37 |
| 2026-10-03 00:00 |
06:31:15.10 |
-43:28:13.2 |
HIP 31126 |
7.60 |
| 2026-10-03 12:00 |
06:31:14.05 |
-43:29:47.4 |
HIP 31126 |
7.12 |
| 2026-10-04 00:00 |
06:31:12.91 |
-43:31:21.5 |
HIP 31126 |
7.00 |
| 2026-10-04 12:00 |
06:31:11.68 |
-43:32:55.6 |
HIP 31126 |
7.24 |
| 2026-10-05 00:00 |
06:31:10.35 |
-43:34:29.7 |
HIP 31126 |
7.82 |
| 2026-10-05 12:00 |
06:31:08.93 |
-43:36:03.6 |
HIP 31061 |
7.01 |
| 2026-10-06 00:00 |
06:31:07.41 |
-43:37:37.5 |
HIP 31061 |
5.43 |
| 2026-10-06 12:00 |
06:31:05.79 |
-43:39:11.3 |
HIP 31061 |
3.85 |
| 2026-10-07 00:00 |
06:31:04.08 |
-43:40:44.9 |
HIP 31061 |
2.28 |
| 2026-10-07 12:00 |
06:31:02.27 |
-43:42:18.5 |
HIP 31061 |
0.83 |
| 2026-10-08 00:00 |
06:31:00.37 |
-43:43:51.9 |
HIP 31061 |
1.13 |
| 2026-10-08 12:00 |
06:30:58.37 |
-43:45:25.3 |
HIP 31061 |
2.64 |
| 2026-10-09 00:00 |
06:30:56.28 |
-43:46:58.4 |
HIP 31061 |
4.22 |
| 2026-10-09 12:00 |
06:30:54.09 |
-43:48:31.5 |
HIP 31061 |
5.81 |
| 2026-10-10 00:00 |
06:30:51.80 |
-43:50:04.4 |
HIP 31061 |
7.41 |
| 2026-10-10 12:00 |
06:30:49.42 |
-43:51:37.1 |
HIP 31061 |
9.01 |
| 2026-10-11 00:00 |
06:30:46.94 |
-43:53:09.6 |
HIP 31061 |
10.62 |