| Parameter |
Value |
| Designation |
C/2005 J2 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2005-04-04T06:52:12.155520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-16T12:11:39Z |
| Obs used |
65 |
| NEO |
- |
| M1 |
9.000 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2005-05-25.0000000 |
| e |
1.00000000 |
| q (au) |
4.287489 |
| a (au) |
-433338614767.913574 |
| i (deg) |
150.803021 |
| Ω (om, deg) |
33.369506 |
| ω (w, deg) |
199.642613 |
| M (ma, deg) |
0.000000 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.585 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.585 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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 |
03:24:18.02 |
+09:13:18.3 |
HIP 15900 |
13.84 |
| 2026-09-20 12:00 |
03:24:16.10 |
+09:13:06.6 |
HIP 15900 |
13.95 |
| 2026-09-21 00:00 |
03:24:14.17 |
+09:12:54.8 |
HIP 15900 |
14.07 |
| 2026-09-21 12:00 |
03:24:12.21 |
+09:12:43.0 |
HIP 15900 |
14.22 |
| 2026-09-22 00:00 |
03:24:10.24 |
+09:12:31.2 |
HIP 15900 |
14.38 |
| 2026-09-22 12:00 |
03:24:08.24 |
+09:12:19.3 |
HIP 15900 |
14.57 |
| 2026-09-23 00:00 |
03:24:06.22 |
+09:12:07.3 |
HIP 15900 |
14.78 |
| 2026-09-23 12:00 |
03:24:04.18 |
+09:11:55.3 |
HIP 15900 |
15.00 |
| 2026-09-24 00:00 |
03:24:02.12 |
+09:11:43.3 |
HIP 15900 |
15.25 |
| 2026-09-24 12:00 |
03:24:00.04 |
+09:11:31.2 |
HIP 15900 |
15.51 |
| 2026-09-25 00:00 |
03:23:57.93 |
+09:11:19.1 |
HIP 15900 |
15.80 |
| 2026-09-25 12:00 |
03:23:55.81 |
+09:11:07.0 |
HIP 15900 |
16.10 |
| 2026-09-26 00:00 |
03:23:53.67 |
+09:10:54.8 |
HIP 15900 |
16.42 |
| 2026-09-26 12:00 |
03:23:51.51 |
+09:10:42.6 |
HIP 15900 |
16.75 |
| 2026-09-27 00:00 |
03:23:49.32 |
+09:10:30.3 |
HIP 15900 |
17.10 |
| 2026-09-27 12:00 |
03:23:47.12 |
+09:10:18.0 |
HIP 15900 |
17.47 |
| 2026-09-28 00:00 |
03:23:44.90 |
+09:10:05.7 |
HIP 15900 |
17.86 |
| 2026-09-28 12:00 |
03:23:42.66 |
+09:09:53.3 |
HIP 15900 |
18.25 |
| 2026-09-29 00:00 |
03:23:40.40 |
+09:09:40.9 |
HIP 15900 |
18.67 |
| 2026-09-29 12:00 |
03:23:38.12 |
+09:09:28.5 |
HIP 15900 |
19.09 |
| 2026-09-30 00:00 |
03:23:35.82 |
+09:09:16.0 |
HIP 15810 |
18.96 |
| 2026-09-30 12:00 |
03:23:33.50 |
+09:09:03.5 |
HIP 15810 |
18.79 |
| 2026-10-01 00:00 |
03:23:31.16 |
+09:08:51.0 |
HIP 15810 |
18.63 |
| 2026-10-01 12:00 |
03:23:28.80 |
+09:08:38.4 |
HIP 15810 |
18.50 |
| 2026-10-02 00:00 |
03:23:26.43 |
+09:08:25.8 |
HIP 15810 |
18.39 |
| 2026-10-02 12:00 |
03:23:24.03 |
+09:08:13.2 |
HIP 15810 |
18.30 |
| 2026-10-03 00:00 |
03:23:21.62 |
+09:08:00.6 |
HIP 15810 |
18.23 |
| 2026-10-03 12:00 |
03:23:19.19 |
+09:07:47.9 |
HIP 15810 |
18.19 |
| 2026-10-04 00:00 |
03:23:16.74 |
+09:07:35.2 |
HIP 15810 |
18.16 |
| 2026-10-04 12:00 |
03:23:14.27 |
+09:07:22.5 |
HIP 15810 |
18.16 |
| 2026-10-05 00:00 |
03:23:11.79 |
+09:07:09.8 |
HIP 15810 |
18.19 |
| 2026-10-05 12:00 |
03:23:09.29 |
+09:06:57.0 |
HIP 15810 |
18.24 |
| 2026-10-06 00:00 |
03:23:06.77 |
+09:06:44.3 |
HIP 15810 |
18.31 |
| 2026-10-06 12:00 |
03:23:04.23 |
+09:06:31.5 |
HIP 15810 |
18.41 |
| 2026-10-07 00:00 |
03:23:01.68 |
+09:06:18.7 |
HIP 15810 |
18.54 |
| 2026-10-07 12:00 |
03:22:59.10 |
+09:06:05.9 |
HIP 15810 |
18.69 |
| 2026-10-08 00:00 |
03:22:56.52 |
+09:05:53.0 |
HIP 15810 |
18.86 |
| 2026-10-08 12:00 |
03:22:53.91 |
+09:05:40.2 |
HIP 15810 |
19.06 |
| 2026-10-09 00:00 |
03:22:51.29 |
+09:05:27.3 |
HIP 15810 |
19.28 |
| 2026-10-09 12:00 |
03:22:48.65 |
+09:05:14.4 |
HIP 15810 |
19.53 |
| 2026-10-10 00:00 |
03:22:46.00 |
+09:05:01.5 |
HIP 15810 |
19.80 |
| 2026-10-10 12:00 |
03:22:43.33 |
+09:04:48.6 |
HIP 15810 |
20.09 |
| 2026-10-11 00:00 |
03:22:40.64 |
+09:04:35.7 |
HIP 15810 |
20.41 |