| Parameter |
Value |
| Designation |
C/2012 J1 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2012-12-07T05:37:22.232640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:08Z |
| Obs used |
4401 |
| NEO |
- |
| M1 |
6.000 |
| K1 |
12.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-11-16.0000000 |
| e |
1.00132777 |
| q (au) |
3.158711 |
| a (au) |
-2378.965648 |
| i (deg) |
34.186089 |
| Ω (om, deg) |
235.217062 |
| ω (w, deg) |
147.272733 |
| M (ma, deg) |
-0.000180 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.312 + 4.942\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.312 |
| n |
4.942 |
| gf |
1.000 |
| gb |
-0.923 |
| 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) |
| 2026-05-12 00:00 |
10:12:38.66 |
-24:01:30.2 |
HIP 49982 |
6.92 |
| 2026-05-12 12:00 |
10:12:38.30 |
-24:00:53.5 |
HIP 49982 |
7.29 |
| 2026-05-13 00:00 |
10:12:37.97 |
-24:00:17.0 |
HIP 49982 |
7.70 |
| 2026-05-13 12:00 |
10:12:37.68 |
-23:59:40.7 |
HIP 49982 |
8.13 |
| 2026-05-14 00:00 |
10:12:37.43 |
-23:59:04.4 |
HIP 49982 |
8.59 |
| 2026-05-14 12:00 |
10:12:37.21 |
-23:58:28.3 |
HIP 49982 |
9.07 |
| 2026-05-15 00:00 |
10:12:37.02 |
-23:57:52.3 |
HIP 49982 |
9.57 |
| 2026-05-15 12:00 |
10:12:36.88 |
-23:57:16.5 |
HIP 49982 |
10.08 |
| 2026-05-16 00:00 |
10:12:36.76 |
-23:56:40.7 |
HIP 49982 |
10.60 |
| 2026-05-16 12:00 |
10:12:36.69 |
-23:56:05.2 |
HIP 49982 |
11.13 |
| 2026-05-17 00:00 |
10:12:36.65 |
-23:55:29.7 |
HIP 49982 |
11.67 |
| 2026-05-17 12:00 |
10:12:36.64 |
-23:54:54.4 |
HIP 49982 |
12.21 |
| 2026-05-18 00:00 |
10:12:36.67 |
-23:54:19.3 |
HIP 49982 |
12.75 |
| 2026-05-18 12:00 |
10:12:36.74 |
-23:53:44.3 |
HIP 49982 |
13.31 |
| 2026-05-19 00:00 |
10:12:36.84 |
-23:53:09.5 |
HIP 49982 |
13.86 |
| 2026-05-19 12:00 |
10:12:36.97 |
-23:52:34.8 |
HIP 49982 |
14.41 |
| 2026-05-20 00:00 |
10:12:37.14 |
-23:52:00.3 |
HIP 49982 |
14.97 |
| 2026-05-20 12:00 |
10:12:37.35 |
-23:51:25.9 |
HIP 49982 |
15.53 |
| 2026-05-21 00:00 |
10:12:37.59 |
-23:50:51.7 |
HIP 49982 |
16.09 |
| 2026-05-21 12:00 |
10:12:37.87 |
-23:50:17.7 |
HIP 49982 |
16.65 |
| 2026-05-22 00:00 |
10:12:38.18 |
-23:49:43.8 |
HIP 49982 |
17.21 |
| 2026-05-22 12:00 |
10:12:38.53 |
-23:49:10.2 |
HIP 49982 |
17.77 |
| 2026-05-23 00:00 |
10:12:38.91 |
-23:48:36.6 |
HIP 49982 |
18.33 |
| 2026-05-23 12:00 |
10:12:39.33 |
-23:48:03.3 |
HIP 49982 |
18.89 |
| 2026-05-24 00:00 |
10:12:39.78 |
-23:47:30.1 |
HIP 49982 |
19.45 |
| 2026-05-24 12:00 |
10:12:40.27 |
-23:46:57.2 |
HIP 49982 |
20.01 |
| 2026-05-25 00:00 |
10:12:40.79 |
-23:46:24.4 |
HIP 50142 |
20.32 |
| 2026-05-25 12:00 |
10:12:41.35 |
-23:45:51.7 |
HIP 50142 |
20.27 |
| 2026-05-26 00:00 |
10:12:41.94 |
-23:45:19.3 |
HIP 50142 |
20.22 |
| 2026-05-26 12:00 |
10:12:42.56 |
-23:44:47.1 |
HIP 50142 |
20.18 |
| 2026-05-27 00:00 |
10:12:43.22 |
-23:44:15.0 |
HIP 50142 |
20.15 |
| 2026-05-27 12:00 |
10:12:43.92 |
-23:43:43.2 |
HIP 50142 |
20.12 |
| 2026-05-28 00:00 |
10:12:44.64 |
-23:43:11.5 |
HIP 50142 |
20.10 |
| 2026-05-28 12:00 |
10:12:45.41 |
-23:42:40.0 |
HIP 50142 |
20.09 |
| 2026-05-29 00:00 |
10:12:46.20 |
-23:42:08.7 |
HIP 50142 |
20.09 |
| 2026-05-29 12:00 |
10:12:47.03 |
-23:41:37.7 |
HIP 50142 |
20.09 |
| 2026-05-30 00:00 |
10:12:47.90 |
-23:41:06.8 |
HIP 50142 |
20.10 |
| 2026-05-30 12:00 |
10:12:48.80 |
-23:40:36.1 |
HIP 50142 |
20.11 |
| 2026-05-31 00:00 |
10:12:49.73 |
-23:40:05.7 |
HIP 50142 |
20.13 |
| 2026-05-31 12:00 |
10:12:50.69 |
-23:39:35.4 |
HIP 50142 |
20.16 |
| 2026-06-01 00:00 |
10:12:51.69 |
-23:39:05.4 |
HIP 50142 |
20.20 |
| 2026-06-01 12:00 |
10:12:52.72 |
-23:38:35.5 |
HIP 50142 |
20.24 |
| 2026-06-02 00:00 |
10:12:53.79 |
-23:38:05.9 |
HIP 50142 |
20.28 |