| Parameter |
Value |
| Designation |
C/2013 S1 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-08-02T22:01:29.435520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:40Z |
| Obs used |
109 |
| NEO |
- |
| M1 |
13.500 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-10-10.0000000 |
| e |
1.00043244 |
| q (au) |
2.824323 |
| a (au) |
-6531.154578 |
| i (deg) |
83.961966 |
| Ω (om, deg) |
221.536559 |
| ω (w, deg) |
166.064281 |
| M (ma, deg) |
0.000127 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.895 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.895 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-0.503 |
| k |
0.800 |
| δ90 |
9.999 |
| 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) |
| 2026-06-01 00:00 |
11:55:46.14 |
-58:21:52.3 |
HIP 58257 |
9.14 |
| 2026-06-01 12:00 |
11:55:44.34 |
-58:20:53.5 |
HIP 58265 |
9.63 |
| 2026-06-02 00:00 |
11:55:42.61 |
-58:19:54.8 |
HIP 58265 |
9.73 |
| 2026-06-02 12:00 |
11:55:40.94 |
-58:18:56.0 |
HIP 58265 |
9.92 |
| 2026-06-03 00:00 |
11:55:39.33 |
-58:17:57.2 |
HIP 58265 |
10.19 |
| 2026-06-03 12:00 |
11:55:37.78 |
-58:16:58.4 |
HIP 58265 |
10.55 |
| 2026-06-04 00:00 |
11:55:36.30 |
-58:15:59.6 |
HIP 58265 |
10.97 |
| 2026-06-04 12:00 |
11:55:34.87 |
-58:15:00.9 |
HIP 58265 |
11.47 |
| 2026-06-05 00:00 |
11:55:33.51 |
-58:14:02.1 |
HIP 58265 |
12.01 |
| 2026-06-05 12:00 |
11:55:32.21 |
-58:13:03.3 |
HIP 58265 |
12.61 |
| 2026-06-06 00:00 |
11:55:30.97 |
-58:12:04.6 |
HIP 58265 |
13.25 |
| 2026-06-06 12:00 |
11:55:29.79 |
-58:11:05.8 |
HIP 58265 |
13.92 |
| 2026-06-07 00:00 |
11:55:28.67 |
-58:10:07.1 |
HIP 58265 |
14.62 |
| 2026-06-07 12:00 |
11:55:27.62 |
-58:09:08.5 |
HIP 58265 |
15.35 |
| 2026-06-08 00:00 |
11:55:26.62 |
-58:08:09.8 |
HIP 58294 |
15.36 |
| 2026-06-08 12:00 |
11:55:25.69 |
-58:07:11.2 |
HIP 58294 |
15.20 |
| 2026-06-09 00:00 |
11:55:24.82 |
-58:06:12.6 |
HIP 58294 |
15.08 |
| 2026-06-09 12:00 |
11:55:24.01 |
-58:05:14.1 |
HIP 58294 |
15.03 |
| 2026-06-10 00:00 |
11:55:23.26 |
-58:04:15.6 |
HIP 58294 |
15.03 |
| 2026-06-10 12:00 |
11:55:22.58 |
-58:03:17.2 |
HIP 58294 |
15.08 |
| 2026-06-11 00:00 |
11:55:21.95 |
-58:02:18.8 |
HIP 58294 |
15.19 |
| 2026-06-11 12:00 |
11:55:21.39 |
-58:01:20.5 |
HIP 58294 |
15.35 |
| 2026-06-12 00:00 |
11:55:20.89 |
-58:00:22.3 |
HIP 58294 |
15.57 |
| 2026-06-12 12:00 |
11:55:20.45 |
-57:59:24.1 |
HIP 58294 |
15.83 |
| 2026-06-13 00:00 |
11:55:20.07 |
-57:58:26.0 |
HIP 58294 |
16.14 |
| 2026-06-13 12:00 |
11:55:19.76 |
-57:57:28.0 |
HIP 58294 |
16.49 |
| 2026-06-14 00:00 |
11:55:19.50 |
-57:56:30.1 |
HIP 58294 |
16.88 |
| 2026-06-14 12:00 |
11:55:19.31 |
-57:55:32.2 |
HIP 58294 |
17.31 |
| 2026-06-15 00:00 |
11:55:19.18 |
-57:54:34.5 |
HIP 58294 |
17.78 |
| 2026-06-15 12:00 |
11:55:19.11 |
-57:53:36.8 |
HIP 58294 |
18.27 |
| 2026-06-16 00:00 |
11:55:19.10 |
-57:52:39.2 |
HIP 58294 |
18.79 |
| 2026-06-16 12:00 |
11:55:19.15 |
-57:51:41.8 |
HIP 58294 |
19.34 |
| 2026-06-17 00:00 |
11:55:19.27 |
-57:50:44.4 |
HIP 58294 |
19.92 |
| 2026-06-17 12:00 |
11:55:19.44 |
-57:49:47.2 |
HIP 58294 |
20.51 |
| 2026-06-18 00:00 |
11:55:19.68 |
-57:48:50.1 |
HIP 58294 |
21.12 |
| 2026-06-18 12:00 |
11:55:19.97 |
-57:47:53.1 |
HIP 58294 |
21.75 |
| 2026-06-19 00:00 |
11:55:20.33 |
-57:46:56.2 |
HIP 58294 |
22.40 |
| 2026-06-19 12:00 |
11:55:20.75 |
-57:45:59.5 |
HIP 58294 |
23.06 |
| 2026-06-20 00:00 |
11:55:21.23 |
-57:45:02.9 |
HIP 58041 |
22.47 |
| 2026-06-20 12:00 |
11:55:21.76 |
-57:44:06.4 |
HIP 58041 |
21.65 |
| 2026-06-21 00:00 |
11:55:22.36 |
-57:43:10.0 |
HIP 58041 |
20.85 |
| 2026-06-21 12:00 |
11:55:23.02 |
-57:42:13.9 |
HIP 58041 |
20.06 |
| 2026-06-22 00:00 |
11:55:23.74 |
-57:41:17.8 |
HIP 58041 |
19.29 |