| Parameter |
Value |
| Designation |
C/2013 G5 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-09-01T12:06:25.499520Z |
| Orbit solution date (soln_date, UTC) |
2022-06-07T21:44:04Z |
| Obs used |
114 |
| NEO |
- |
| M1 |
14.300 |
| K1 |
11.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-04-23.0000000 |
| e |
0.99971461 |
| q (au) |
0.928919 |
| a (au) |
3254.937233 |
| i (deg) |
40.613476 |
| Ω (om, deg) |
144.282160 |
| ω (w, deg) |
165.667285 |
| M (ma, deg) |
359.999302 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.455 + 2.768\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.455 |
| n |
2.768 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
1.000 |
| 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 |
07:31:28.45 |
+00:06:26.9 |
HIP 36538 |
8.28 |
| 2026-05-12 12:00 |
07:31:30.53 |
+00:06:42.6 |
HIP 36538 |
8.68 |
| 2026-05-13 00:00 |
07:31:32.63 |
+00:06:58.2 |
HIP 36538 |
9.11 |
| 2026-05-13 12:00 |
07:31:34.76 |
+00:07:13.6 |
HIP 36538 |
9.57 |
| 2026-05-14 00:00 |
07:31:36.92 |
+00:07:28.8 |
HIP 36538 |
10.04 |
| 2026-05-14 12:00 |
07:31:39.10 |
+00:07:43.9 |
HIP 36538 |
10.54 |
| 2026-05-15 00:00 |
07:31:41.31 |
+00:07:58.8 |
HIP 36538 |
11.05 |
| 2026-05-15 12:00 |
07:31:43.55 |
+00:08:13.5 |
HIP 36538 |
11.58 |
| 2026-05-16 00:00 |
07:31:45.81 |
+00:08:28.0 |
HIP 36538 |
12.13 |
| 2026-05-16 12:00 |
07:31:48.10 |
+00:08:42.4 |
HIP 36538 |
12.68 |
| 2026-05-17 00:00 |
07:31:50.42 |
+00:08:56.6 |
HIP 36538 |
13.25 |
| 2026-05-17 12:00 |
07:31:52.76 |
+00:09:10.7 |
HIP 36538 |
13.83 |
| 2026-05-18 00:00 |
07:31:55.13 |
+00:09:24.5 |
HIP 36538 |
14.42 |
| 2026-05-18 12:00 |
07:31:57.52 |
+00:09:38.2 |
HIP 36538 |
15.02 |
| 2026-05-19 00:00 |
07:31:59.93 |
+00:09:51.7 |
HIP 36538 |
15.63 |
| 2026-05-19 12:00 |
07:32:02.37 |
+00:10:05.1 |
HIP 36538 |
16.25 |
| 2026-05-20 00:00 |
07:32:04.84 |
+00:10:18.3 |
HIP 36538 |
16.88 |
| 2026-05-20 12:00 |
07:32:07.33 |
+00:10:31.2 |
HIP 36730 |
16.60 |
| 2026-05-21 00:00 |
07:32:09.84 |
+00:10:44.1 |
HIP 36730 |
15.98 |
| 2026-05-21 12:00 |
07:32:12.38 |
+00:10:56.7 |
HIP 36730 |
15.36 |
| 2026-05-22 00:00 |
07:32:14.94 |
+00:11:09.2 |
HIP 36730 |
14.74 |
| 2026-05-22 12:00 |
07:32:17.53 |
+00:11:21.4 |
HIP 36730 |
14.12 |
| 2026-05-23 00:00 |
07:32:20.14 |
+00:11:33.6 |
HIP 36730 |
13.49 |
| 2026-05-23 12:00 |
07:32:22.77 |
+00:11:45.5 |
HIP 36730 |
12.87 |
| 2026-05-24 00:00 |
07:32:25.43 |
+00:11:57.2 |
HIP 36730 |
12.24 |
| 2026-05-24 12:00 |
07:32:28.11 |
+00:12:08.8 |
HIP 36730 |
11.62 |
| 2026-05-25 00:00 |
07:32:30.81 |
+00:12:20.2 |
HIP 36730 |
11.00 |
| 2026-05-25 12:00 |
07:32:33.53 |
+00:12:31.4 |
HIP 36730 |
10.38 |
| 2026-05-26 00:00 |
07:32:36.28 |
+00:12:42.4 |
HIP 36730 |
9.77 |
| 2026-05-26 12:00 |
07:32:39.04 |
+00:12:53.3 |
HIP 36730 |
9.17 |
| 2026-05-27 00:00 |
07:32:41.83 |
+00:13:03.9 |
HIP 36730 |
8.58 |
| 2026-05-27 12:00 |
07:32:44.64 |
+00:13:14.4 |
HIP 36730 |
8.01 |
| 2026-05-28 00:00 |
07:32:47.47 |
+00:13:24.7 |
HIP 36730 |
7.45 |
| 2026-05-28 12:00 |
07:32:50.33 |
+00:13:34.8 |
HIP 36730 |
6.92 |
| 2026-05-29 00:00 |
07:32:53.20 |
+00:13:44.8 |
HIP 36730 |
6.43 |
| 2026-05-29 12:00 |
07:32:56.10 |
+00:13:54.5 |
HIP 36730 |
5.98 |
| 2026-05-30 00:00 |
07:32:59.01 |
+00:14:04.1 |
HIP 36730 |
5.58 |
| 2026-05-30 12:00 |
07:33:01.95 |
+00:14:13.5 |
HIP 36730 |
5.26 |
| 2026-05-31 00:00 |
07:33:04.90 |
+00:14:22.7 |
HIP 36730 |
5.02 |
| 2026-05-31 12:00 |
07:33:07.88 |
+00:14:31.7 |
HIP 36730 |
4.89 |
| 2026-06-01 00:00 |
07:33:10.88 |
+00:14:40.5 |
HIP 36730 |
4.87 |
| 2026-06-01 12:00 |
07:33:13.89 |
+00:14:49.2 |
HIP 36730 |
4.96 |
| 2026-06-02 00:00 |
07:33:16.93 |
+00:14:57.6 |
HIP 36730 |
5.17 |