| 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) |
| 2026-05-12 00:00 |
15:24:03.52 |
-02:25:57.3 |
HIP 75456 |
17.51 |
| 2026-05-12 12:00 |
15:23:58.48 |
-02:25:48.4 |
HIP 75456 |
18.36 |
| 2026-05-13 00:00 |
15:23:53.45 |
-02:25:39.7 |
HIP 75456 |
19.26 |
| 2026-05-13 12:00 |
15:23:48.41 |
-02:25:31.2 |
HIP 75456 |
20.20 |
| 2026-05-14 00:00 |
15:23:43.37 |
-02:25:22.9 |
HIP 75456 |
21.18 |
| 2026-05-14 12:00 |
15:23:38.34 |
-02:25:14.7 |
HIP 75311 |
21.81 |
| 2026-05-15 00:00 |
15:23:33.30 |
-02:25:06.8 |
HIP 75311 |
21.59 |
| 2026-05-15 12:00 |
15:23:28.27 |
-02:24:59.0 |
HIP 75311 |
21.43 |
| 2026-05-16 00:00 |
15:23:23.24 |
-02:24:51.4 |
HIP 75311 |
21.35 |
| 2026-05-16 12:00 |
15:23:18.21 |
-02:24:44.1 |
HIP 75311 |
21.34 |
| 2026-05-17 00:00 |
15:23:13.18 |
-02:24:36.9 |
HIP 75311 |
21.40 |
| 2026-05-17 12:00 |
15:23:08.16 |
-02:24:29.9 |
HIP 75311 |
21.53 |
| 2026-05-18 00:00 |
15:23:03.14 |
-02:24:23.1 |
HIP 75311 |
21.73 |
| 2026-05-18 12:00 |
15:22:58.12 |
-02:24:16.5 |
HIP 75311 |
21.99 |
| 2026-05-19 00:00 |
15:22:53.11 |
-02:24:10.2 |
HIP 75311 |
22.32 |
| 2026-05-19 12:00 |
15:22:48.11 |
-02:24:04.0 |
HIP 75311 |
22.71 |
| 2026-05-20 00:00 |
15:22:43.11 |
-02:23:58.0 |
HIP 75311 |
23.16 |
| 2026-05-20 12:00 |
15:22:38.12 |
-02:23:52.2 |
HIP 75311 |
23.66 |
| 2026-05-21 00:00 |
15:22:33.13 |
-02:23:46.7 |
HIP 75311 |
24.22 |
| 2026-05-21 12:00 |
15:22:28.15 |
-02:23:41.3 |
HIP 75311 |
24.82 |
| 2026-05-22 00:00 |
15:22:23.18 |
-02:23:36.2 |
HIP 75101 |
24.01 |
| 2026-05-22 12:00 |
15:22:18.21 |
-02:23:31.2 |
HIP 75101 |
22.77 |
| 2026-05-23 00:00 |
15:22:13.26 |
-02:23:26.5 |
HIP 75101 |
21.54 |
| 2026-05-23 12:00 |
15:22:08.31 |
-02:23:22.0 |
HIP 75101 |
20.31 |
| 2026-05-24 00:00 |
15:22:03.37 |
-02:23:17.7 |
HIP 75101 |
19.09 |
| 2026-05-24 12:00 |
15:21:58.44 |
-02:23:13.6 |
HIP 75101 |
17.87 |
| 2026-05-25 00:00 |
15:21:53.52 |
-02:23:09.7 |
HIP 75101 |
16.65 |
| 2026-05-25 12:00 |
15:21:48.61 |
-02:23:06.0 |
HIP 75101 |
15.44 |
| 2026-05-26 00:00 |
15:21:43.71 |
-02:23:02.6 |
HIP 75101 |
14.23 |
| 2026-05-26 12:00 |
15:21:38.82 |
-02:22:59.3 |
HIP 75101 |
13.02 |
| 2026-05-27 00:00 |
15:21:33.94 |
-02:22:56.3 |
HIP 75101 |
11.83 |
| 2026-05-27 12:00 |
15:21:29.08 |
-02:22:53.5 |
HIP 75101 |
10.63 |
| 2026-05-28 00:00 |
15:21:24.22 |
-02:22:50.9 |
HIP 75101 |
9.45 |
| 2026-05-28 12:00 |
15:21:19.38 |
-02:22:48.5 |
HIP 75101 |
8.28 |
| 2026-05-29 00:00 |
15:21:14.55 |
-02:22:46.4 |
HIP 75101 |
7.13 |
| 2026-05-29 12:00 |
15:21:09.73 |
-02:22:44.4 |
HIP 75101 |
5.99 |
| 2026-05-30 00:00 |
15:21:04.93 |
-02:22:42.7 |
HIP 75101 |
4.89 |
| 2026-05-30 12:00 |
15:21:00.14 |
-02:22:41.2 |
HIP 75101 |
3.85 |
| 2026-05-31 00:00 |
15:20:55.37 |
-02:22:39.9 |
HIP 75101 |
2.94 |
| 2026-05-31 12:00 |
15:20:50.60 |
-02:22:38.9 |
HIP 75101 |
2.29 |
| 2026-06-01 00:00 |
15:20:45.86 |
-02:22:38.1 |
HIP 75101 |
2.17 |
| 2026-06-01 12:00 |
15:20:41.13 |
-02:22:37.5 |
HIP 75101 |
2.63 |
| 2026-06-02 00:00 |
15:20:36.41 |
-02:22:37.1 |
HIP 75101 |
3.45 |