| Parameter |
Value |
| Designation |
C/2013 F2 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-04-19T00:12:51.621120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:32Z |
| Obs used |
168 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-07-28.0000000 |
| e |
0.99925889 |
| q (au) |
6.217862 |
| a (au) |
8389.886246 |
| i (deg) |
61.749267 |
| Ω (om, deg) |
344.272220 |
| ω (w, deg) |
122.991132 |
| M (ma, deg) |
0.000128 |
Magnitude
Scatter + Global Linear
$$
M_a = (2.163 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
2.163 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
11:27:00.42 |
-59:07:58.8 |
HIP 55801 |
15.20 |
| 2026-05-12 12:00 |
11:26:56.49 |
-59:07:09.2 |
HIP 55801 |
15.69 |
| 2026-05-13 00:00 |
11:26:52.62 |
-59:06:19.5 |
HIP 55801 |
16.23 |
| 2026-05-13 12:00 |
11:26:48.82 |
-59:05:29.5 |
HIP 55801 |
16.81 |
| 2026-05-14 00:00 |
11:26:45.08 |
-59:04:39.5 |
HIP 55801 |
17.43 |
| 2026-05-14 12:00 |
11:26:41.41 |
-59:03:49.3 |
HIP 55801 |
18.09 |
| 2026-05-15 00:00 |
11:26:37.81 |
-59:02:58.9 |
HIP 55801 |
18.78 |
| 2026-05-15 12:00 |
11:26:34.27 |
-59:02:08.4 |
HIP 55801 |
19.49 |
| 2026-05-16 00:00 |
11:26:30.79 |
-59:01:17.8 |
HIP 55801 |
20.23 |
| 2026-05-16 12:00 |
11:26:27.39 |
-59:00:27.0 |
HIP 55801 |
20.99 |
| 2026-05-17 00:00 |
11:26:24.05 |
-58:59:36.2 |
HIP 55801 |
21.76 |
| 2026-05-17 12:00 |
11:26:20.77 |
-58:58:45.2 |
HIP 55938 |
21.40 |
| 2026-05-18 00:00 |
11:26:17.57 |
-58:57:54.1 |
HIP 55938 |
20.93 |
| 2026-05-18 12:00 |
11:26:14.43 |
-58:57:03.0 |
HIP 55938 |
20.49 |
| 2026-05-19 00:00 |
11:26:11.35 |
-58:56:11.7 |
HIP 55938 |
20.07 |
| 2026-05-19 12:00 |
11:26:08.35 |
-58:55:20.3 |
HIP 55938 |
19.69 |
| 2026-05-20 00:00 |
11:26:05.41 |
-58:54:28.9 |
HIP 55938 |
19.33 |
| 2026-05-20 12:00 |
11:26:02.54 |
-58:53:37.3 |
HIP 55938 |
19.01 |
| 2026-05-21 00:00 |
11:25:59.74 |
-58:52:45.7 |
HIP 55938 |
18.72 |
| 2026-05-21 12:00 |
11:25:57.00 |
-58:51:54.1 |
HIP 55938 |
18.47 |
| 2026-05-22 00:00 |
11:25:54.33 |
-58:51:02.3 |
HIP 55938 |
18.26 |
| 2026-05-22 12:00 |
11:25:51.73 |
-58:50:10.5 |
HIP 55938 |
18.08 |
| 2026-05-23 00:00 |
11:25:49.20 |
-58:49:18.7 |
HIP 55938 |
17.94 |
| 2026-05-23 12:00 |
11:25:46.74 |
-58:48:26.7 |
HIP 55938 |
17.84 |
| 2026-05-24 00:00 |
11:25:44.34 |
-58:47:34.8 |
HIP 55938 |
17.78 |
| 2026-05-24 12:00 |
11:25:42.01 |
-58:46:42.8 |
HIP 55938 |
17.75 |
| 2026-05-25 00:00 |
11:25:39.75 |
-58:45:50.8 |
HIP 55938 |
17.77 |
| 2026-05-25 12:00 |
11:25:37.55 |
-58:44:58.7 |
HIP 55938 |
17.83 |
| 2026-05-26 00:00 |
11:25:35.43 |
-58:44:06.6 |
HIP 55938 |
17.92 |
| 2026-05-26 12:00 |
11:25:33.37 |
-58:43:14.5 |
HIP 55938 |
18.05 |
| 2026-05-27 00:00 |
11:25:31.38 |
-58:42:22.4 |
HIP 55594 |
18.05 |
| 2026-05-27 12:00 |
11:25:29.46 |
-58:41:30.3 |
HIP 55594 |
18.08 |
| 2026-05-28 00:00 |
11:25:27.61 |
-58:40:38.1 |
HIP 55594 |
18.15 |
| 2026-05-28 12:00 |
11:25:25.82 |
-58:39:46.0 |
HIP 55594 |
18.28 |
| 2026-05-29 00:00 |
11:25:24.10 |
-58:38:53.8 |
HIP 55594 |
18.45 |
| 2026-05-29 12:00 |
11:25:22.45 |
-58:38:01.7 |
HIP 55594 |
18.68 |
| 2026-05-30 00:00 |
11:25:20.87 |
-58:37:09.6 |
HIP 55594 |
18.95 |
| 2026-05-30 12:00 |
11:25:19.35 |
-58:36:17.4 |
HIP 55594 |
19.27 |
| 2026-05-31 00:00 |
11:25:17.90 |
-58:35:25.3 |
HIP 55594 |
19.63 |
| 2026-05-31 12:00 |
11:25:16.52 |
-58:34:33.3 |
HIP 55594 |
20.02 |
| 2026-06-01 00:00 |
11:25:15.21 |
-58:33:41.2 |
HIP 55594 |
20.46 |
| 2026-06-01 12:00 |
11:25:13.96 |
-58:32:49.2 |
HIP 55594 |
20.93 |
| 2026-06-02 00:00 |
11:25:12.79 |
-58:31:57.2 |
HIP 55594 |
21.43 |