| Parameter |
Value |
| Designation |
C/2013 V4 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-10-07T13:40:00.877440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:42Z |
| Obs used |
2445 |
| NEO |
- |
| M1 |
6.000 |
| K1 |
9.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-08-24.0000000 |
| e |
1.00261035 |
| q (au) |
5.185419 |
| a (au) |
-1986.485935 |
| i (deg) |
67.854449 |
| Ω (om, deg) |
55.620501 |
| ω (w, deg) |
40.445881 |
| M (ma, deg) |
-0.000496 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.025 + 2.739\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.025 |
| n |
2.739 |
| gf |
0.857 |
| gb |
-0.970 |
| k |
1.000 |
| δ90 |
6.665 |
| 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) |
| 2026-03-26 00:00 |
15:30:57.08 |
-02:49:21.1 |
HIP 75867 |
17.04 |
| 2026-03-26 12:00 |
15:30:53.85 |
-02:49:03.2 |
HIP 75867 |
16.24 |
| 2026-03-27 00:00 |
15:30:50.58 |
-02:48:45.3 |
HIP 75867 |
15.43 |
| 2026-03-27 12:00 |
15:30:47.28 |
-02:48:27.4 |
HIP 75867 |
14.63 |
| 2026-03-28 00:00 |
15:30:43.95 |
-02:48:09.5 |
HIP 75867 |
13.82 |
| 2026-03-28 12:00 |
15:30:40.58 |
-02:47:51.6 |
HIP 75867 |
13.02 |
| 2026-03-29 00:00 |
15:30:37.17 |
-02:47:33.7 |
HIP 75867 |
12.22 |
| 2026-03-29 12:00 |
15:30:33.73 |
-02:47:15.8 |
HIP 75867 |
11.43 |
| 2026-03-30 00:00 |
15:30:30.26 |
-02:46:57.9 |
HIP 75867 |
10.65 |
| 2026-03-30 12:00 |
15:30:26.76 |
-02:46:40.0 |
HIP 75867 |
9.89 |
| 2026-03-31 00:00 |
15:30:23.22 |
-02:46:22.2 |
HIP 75867 |
9.15 |
| 2026-03-31 12:00 |
15:30:19.65 |
-02:46:04.4 |
HIP 75867 |
8.43 |
| 2026-04-01 00:00 |
15:30:16.05 |
-02:45:46.6 |
HIP 75867 |
7.76 |
| 2026-04-01 12:00 |
15:30:12.42 |
-02:45:28.8 |
HIP 75867 |
7.15 |
| 2026-04-02 00:00 |
15:30:08.75 |
-02:45:11.0 |
HIP 75867 |
6.60 |
| 2026-04-02 12:00 |
15:30:05.06 |
-02:44:53.3 |
HIP 75867 |
6.16 |
| 2026-04-03 00:00 |
15:30:01.33 |
-02:44:35.5 |
HIP 75867 |
5.84 |
| 2026-04-03 12:00 |
15:29:57.57 |
-02:44:17.9 |
HIP 75867 |
5.67 |
| 2026-04-04 00:00 |
15:29:53.78 |
-02:44:00.2 |
HIP 75867 |
5.67 |
| 2026-04-04 12:00 |
15:29:49.96 |
-02:43:42.6 |
HIP 75867 |
5.83 |
| 2026-04-05 00:00 |
15:29:46.12 |
-02:43:25.0 |
HIP 75867 |
6.16 |
| 2026-04-05 12:00 |
15:29:42.24 |
-02:43:07.5 |
HIP 75867 |
6.62 |
| 2026-04-06 00:00 |
15:29:38.33 |
-02:42:50.0 |
HIP 75867 |
7.20 |
| 2026-04-06 12:00 |
15:29:34.39 |
-02:42:32.5 |
HIP 75867 |
7.87 |
| 2026-04-07 00:00 |
15:29:30.43 |
-02:42:15.1 |
HIP 75867 |
8.62 |
| 2026-04-07 12:00 |
15:29:26.43 |
-02:41:57.7 |
HIP 75867 |
9.42 |
| 2026-04-08 00:00 |
15:29:22.41 |
-02:41:40.4 |
HIP 75867 |
10.27 |
| 2026-04-08 12:00 |
15:29:18.36 |
-02:41:23.1 |
HIP 75867 |
11.15 |
| 2026-04-09 00:00 |
15:29:14.29 |
-02:41:05.9 |
HIP 75867 |
12.07 |
| 2026-04-09 12:00 |
15:29:10.18 |
-02:40:48.8 |
HIP 75867 |
13.01 |
| 2026-04-10 00:00 |
15:29:06.05 |
-02:40:31.7 |
HIP 75867 |
13.98 |
| 2026-04-10 12:00 |
15:29:01.89 |
-02:40:14.7 |
HIP 75867 |
14.96 |
| 2026-04-11 00:00 |
15:28:57.71 |
-02:39:57.7 |
HIP 75867 |
15.96 |
| 2026-04-11 12:00 |
15:28:53.50 |
-02:39:40.8 |
HIP 75867 |
16.98 |
| 2026-04-12 00:00 |
15:28:49.27 |
-02:39:23.9 |
HIP 75685 |
17.65 |
| 2026-04-12 12:00 |
15:28:45.01 |
-02:39:07.2 |
HIP 75685 |
16.76 |
| 2026-04-13 00:00 |
15:28:40.72 |
-02:38:50.5 |
HIP 75685 |
15.88 |
| 2026-04-13 12:00 |
15:28:36.41 |
-02:38:33.8 |
HIP 75685 |
15.02 |
| 2026-04-14 00:00 |
15:28:32.08 |
-02:38:17.3 |
HIP 75685 |
14.20 |
| 2026-04-14 12:00 |
15:28:27.72 |
-02:38:00.8 |
HIP 75685 |
13.41 |
| 2026-04-15 00:00 |
15:28:23.34 |
-02:37:44.4 |
HIP 75685 |
12.67 |
| 2026-04-15 12:00 |
15:28:18.94 |
-02:37:28.1 |
HIP 75685 |
11.98 |
| 2026-04-16 00:00 |
15:28:14.52 |
-02:37:11.9 |
HIP 75685 |
11.36 |