| 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
$$
M_a = (7.035 + 2.740\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.035 |
| n |
2.740 |
| gf |
0.850 |
| gb |
-0.970 |
| k |
1.000 |
| δ90 |
6.315 |
| 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) |
| 2026-09-20 00:00 |
15:16:20.74 |
-03:42:46.5 |
HIP 74871 |
30.46 |
| 2026-09-20 12:00 |
15:16:23.66 |
-03:43:22.0 |
HIP 74871 |
30.19 |
| 2026-09-21 00:00 |
15:16:26.61 |
-03:43:57.4 |
HIP 74804 |
29.75 |
| 2026-09-21 12:00 |
15:16:29.59 |
-03:44:32.9 |
HIP 74804 |
28.91 |
| 2026-09-22 00:00 |
15:16:32.61 |
-03:45:08.4 |
HIP 74804 |
28.07 |
| 2026-09-22 12:00 |
15:16:35.65 |
-03:45:43.9 |
HIP 74804 |
27.23 |
| 2026-09-23 00:00 |
15:16:38.72 |
-03:46:19.4 |
HIP 74804 |
26.41 |
| 2026-09-23 12:00 |
15:16:41.82 |
-03:46:55.0 |
HIP 74804 |
25.59 |
| 2026-09-24 00:00 |
15:16:44.95 |
-03:47:30.5 |
HIP 74804 |
24.78 |
| 2026-09-24 12:00 |
15:16:48.10 |
-03:48:06.0 |
HIP 74804 |
23.98 |
| 2026-09-25 00:00 |
15:16:51.29 |
-03:48:41.5 |
HIP 74804 |
23.19 |
| 2026-09-25 12:00 |
15:16:54.51 |
-03:49:17.0 |
HIP 74804 |
22.42 |
| 2026-09-26 00:00 |
15:16:57.75 |
-03:49:52.5 |
HIP 74804 |
21.66 |
| 2026-09-26 12:00 |
15:17:01.02 |
-03:50:28.0 |
HIP 74804 |
20.92 |
| 2026-09-27 00:00 |
15:17:04.32 |
-03:51:03.5 |
HIP 74804 |
20.21 |
| 2026-09-27 12:00 |
15:17:07.65 |
-03:51:38.9 |
HIP 74804 |
19.52 |
| 2026-09-28 00:00 |
15:17:11.01 |
-03:52:14.4 |
HIP 74804 |
18.86 |
| 2026-09-28 12:00 |
15:17:14.39 |
-03:52:49.8 |
HIP 74804 |
18.23 |
| 2026-09-29 00:00 |
15:17:17.80 |
-03:53:25.3 |
HIP 74804 |
17.65 |
| 2026-09-29 12:00 |
15:17:21.23 |
-03:54:00.7 |
HIP 74804 |
17.11 |
| 2026-09-30 00:00 |
15:17:24.70 |
-03:54:36.1 |
HIP 74804 |
16.61 |
| 2026-09-30 12:00 |
15:17:28.19 |
-03:55:11.5 |
HIP 74804 |
16.17 |
| 2026-10-01 00:00 |
15:17:31.70 |
-03:55:46.8 |
HIP 74804 |
15.79 |
| 2026-10-01 12:00 |
15:17:35.25 |
-03:56:22.2 |
HIP 74804 |
15.48 |
| 2026-10-02 00:00 |
15:17:38.81 |
-03:56:57.5 |
HIP 74804 |
15.23 |
| 2026-10-02 12:00 |
15:17:42.41 |
-03:57:32.8 |
HIP 74804 |
15.06 |
| 2026-10-03 00:00 |
15:17:46.03 |
-03:58:08.0 |
HIP 74804 |
14.97 |
| 2026-10-03 12:00 |
15:17:49.67 |
-03:58:43.3 |
HIP 74804 |
14.96 |
| 2026-10-04 00:00 |
15:17:53.34 |
-03:59:18.5 |
HIP 74804 |
15.03 |
| 2026-10-04 12:00 |
15:17:57.04 |
-03:59:53.6 |
HIP 74804 |
15.19 |
| 2026-10-05 00:00 |
15:18:00.75 |
-04:00:28.8 |
HIP 74804 |
15.42 |
| 2026-10-05 12:00 |
15:18:04.50 |
-04:01:03.9 |
HIP 74804 |
15.74 |
| 2026-10-06 00:00 |
15:18:08.26 |
-04:01:39.0 |
HIP 74804 |
16.12 |
| 2026-10-06 12:00 |
15:18:12.06 |
-04:02:14.0 |
HIP 74804 |
16.58 |
| 2026-10-07 00:00 |
15:18:15.87 |
-04:02:49.0 |
HIP 74804 |
17.11 |
| 2026-10-07 12:00 |
15:18:19.71 |
-04:03:23.9 |
HIP 74804 |
17.69 |
| 2026-10-08 00:00 |
15:18:23.57 |
-04:03:58.8 |
HIP 74804 |
18.33 |
| 2026-10-08 12:00 |
15:18:27.45 |
-04:04:33.7 |
HIP 74804 |
19.02 |
| 2026-10-09 00:00 |
15:18:31.36 |
-04:05:08.5 |
HIP 74804 |
19.76 |
| 2026-10-09 12:00 |
15:18:35.29 |
-04:05:43.2 |
HIP 74804 |
20.54 |
| 2026-10-10 00:00 |
15:18:39.24 |
-04:06:17.9 |
HIP 74989 |
20.75 |
| 2026-10-10 12:00 |
15:18:43.21 |
-04:06:52.6 |
HIP 74989 |
20.71 |
| 2026-10-11 00:00 |
15:18:47.20 |
-04:07:27.2 |
HIP 74989 |
20.73 |