| 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 |
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 |
11:57:47.28 |
-58:59:58.6 |
HIP 58220 |
14.93 |
| 2026-05-12 12:00 |
11:57:43.12 |
-58:59:04.1 |
HIP 58220 |
13.91 |
| 2026-05-13 00:00 |
11:57:39.00 |
-58:58:09.4 |
HIP 58220 |
12.89 |
| 2026-05-13 12:00 |
11:57:34.95 |
-58:57:14.6 |
HIP 58220 |
11.89 |
| 2026-05-14 00:00 |
11:57:30.95 |
-58:56:19.5 |
HIP 58220 |
10.90 |
| 2026-05-14 12:00 |
11:57:27.00 |
-58:55:24.3 |
HIP 58220 |
9.92 |
| 2026-05-15 00:00 |
11:57:23.12 |
-58:54:28.9 |
HIP 58220 |
8.97 |
| 2026-05-15 12:00 |
11:57:19.29 |
-58:53:33.3 |
HIP 58220 |
8.04 |
| 2026-05-16 00:00 |
11:57:15.51 |
-58:52:37.5 |
HIP 58220 |
7.16 |
| 2026-05-16 12:00 |
11:57:11.80 |
-58:51:41.6 |
HIP 58220 |
6.32 |
| 2026-05-17 00:00 |
11:57:08.14 |
-58:50:45.5 |
HIP 58220 |
5.57 |
| 2026-05-17 12:00 |
11:57:04.54 |
-58:49:49.3 |
HIP 58220 |
4.94 |
| 2026-05-18 00:00 |
11:57:01.00 |
-58:48:52.9 |
HIP 58220 |
4.47 |
| 2026-05-18 12:00 |
11:56:57.52 |
-58:47:56.4 |
HIP 58220 |
4.22 |
| 2026-05-19 00:00 |
11:56:54.09 |
-58:46:59.7 |
HIP 58220 |
4.23 |
| 2026-05-19 12:00 |
11:56:50.73 |
-58:46:02.9 |
HIP 58220 |
4.49 |
| 2026-05-20 00:00 |
11:56:47.42 |
-58:45:06.0 |
HIP 58220 |
4.97 |
| 2026-05-20 12:00 |
11:56:44.18 |
-58:44:08.9 |
HIP 58220 |
5.61 |
| 2026-05-21 00:00 |
11:56:40.99 |
-58:43:11.7 |
HIP 58220 |
6.36 |
| 2026-05-21 12:00 |
11:56:37.86 |
-58:42:14.4 |
HIP 58220 |
7.19 |
| 2026-05-22 00:00 |
11:56:34.79 |
-58:41:17.0 |
HIP 58220 |
8.07 |
| 2026-05-22 12:00 |
11:56:31.79 |
-58:40:19.5 |
HIP 58220 |
8.98 |
| 2026-05-23 00:00 |
11:56:28.84 |
-58:39:21.9 |
HIP 58220 |
9.92 |
| 2026-05-23 12:00 |
11:56:25.95 |
-58:38:24.2 |
HIP 58220 |
10.88 |
| 2026-05-24 00:00 |
11:56:23.12 |
-58:37:26.4 |
HIP 58220 |
11.85 |
| 2026-05-24 12:00 |
11:56:20.36 |
-58:36:28.5 |
HIP 58257 |
12.26 |
| 2026-05-25 00:00 |
11:56:17.65 |
-58:35:30.5 |
HIP 58257 |
11.48 |
| 2026-05-25 12:00 |
11:56:15.00 |
-58:34:32.4 |
HIP 58257 |
10.75 |
| 2026-05-26 00:00 |
11:56:12.42 |
-58:33:34.3 |
HIP 58257 |
10.06 |
| 2026-05-26 12:00 |
11:56:09.89 |
-58:32:36.1 |
HIP 58257 |
9.43 |
| 2026-05-27 00:00 |
11:56:07.43 |
-58:31:37.8 |
HIP 58257 |
8.87 |
| 2026-05-27 12:00 |
11:56:05.03 |
-58:30:39.5 |
HIP 58257 |
8.39 |
| 2026-05-28 00:00 |
11:56:02.68 |
-58:29:41.1 |
HIP 58257 |
8.00 |
| 2026-05-28 12:00 |
11:56:00.40 |
-58:28:42.6 |
HIP 58257 |
7.72 |
| 2026-05-29 00:00 |
11:55:58.18 |
-58:27:44.1 |
HIP 58257 |
7.56 |
| 2026-05-29 12:00 |
11:55:56.02 |
-58:26:45.6 |
HIP 58257 |
7.53 |
| 2026-05-30 00:00 |
11:55:53.92 |
-58:25:47.0 |
HIP 58257 |
7.63 |
| 2026-05-30 12:00 |
11:55:51.88 |
-58:24:48.3 |
HIP 58257 |
7.85 |
| 2026-05-31 00:00 |
11:55:49.91 |
-58:23:49.7 |
HIP 58257 |
8.19 |
| 2026-05-31 12:00 |
11:55:47.99 |
-58:22:51.0 |
HIP 58257 |
8.62 |
| 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 |