| Parameter |
Value |
| Designation |
300P/Catalina |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-11-02T01:00:23.175360Z |
| Orbit solution date (soln_date, UTC) |
2023-11-14T12:36:26Z |
| Obs used |
148 |
| NEO |
Yes |
| M1 |
16.800 |
| K1 |
20.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-01-04.0000000 |
| e |
0.69162623 |
| q (au) |
0.832296 |
| a (au) |
2.698984 |
| i (deg) |
5.675932 |
| Ω (om, deg) |
95.686317 |
| ω (w, deg) |
222.865728 |
| M (ma, deg) |
292.861604 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.367 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.367 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2023-02-17 |
2023-04-11 |
+15.3858 |
+0.614 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
11:30:56.07 |
+07:44:09.8 |
HIP 56234 |
13.29 |
| 2026-09-20 12:00 |
11:31:28.74 |
+07:40:46.0 |
HIP 56234 |
11.39 |
| 2026-09-21 00:00 |
11:32:01.43 |
+07:37:22.0 |
HIP 56234 |
15.39 |
| 2026-09-21 12:00 |
11:32:34.15 |
+07:33:58.0 |
HIP 56355 |
12.44 |
| 2026-09-22 00:00 |
11:33:06.89 |
+07:30:33.9 |
HIP 56355 |
5.91 |
| 2026-09-22 12:00 |
11:33:39.65 |
+07:27:09.7 |
HIP 56355 |
8.37 |
| 2026-09-23 00:00 |
11:34:12.44 |
+07:23:45.4 |
HIP 56355 |
16.14 |
| 2026-09-23 12:00 |
11:34:45.25 |
+07:20:21.0 |
HIP 56355 |
24.63 |
| 2026-09-24 00:00 |
11:35:18.09 |
+07:16:56.6 |
HIP 56574 |
32.28 |
| 2026-09-24 12:00 |
11:35:50.95 |
+07:13:32.1 |
HIP 56574 |
27.48 |
| 2026-09-25 00:00 |
11:36:23.83 |
+07:10:07.5 |
HIP 56574 |
24.98 |
| 2026-09-25 12:00 |
11:36:56.73 |
+07:06:42.9 |
HIP 56574 |
25.49 |
| 2026-09-26 00:00 |
11:37:29.65 |
+07:03:18.1 |
HIP 56812 |
27.98 |
| 2026-09-26 12:00 |
11:38:02.60 |
+06:59:53.4 |
HIP 56812 |
26.24 |
| 2026-09-27 00:00 |
11:38:35.56 |
+06:56:28.5 |
HIP 56787 |
26.48 |
| 2026-09-27 12:00 |
11:39:08.55 |
+06:53:03.6 |
HIP 56787 |
24.71 |
| 2026-09-28 00:00 |
11:39:41.56 |
+06:49:38.7 |
HIP 56787 |
26.02 |
| 2026-09-28 12:00 |
11:40:14.59 |
+06:46:13.7 |
HIP 57071 |
25.59 |
| 2026-09-29 00:00 |
11:40:47.64 |
+06:42:48.7 |
HIP 57071 |
18.18 |
| 2026-09-29 12:00 |
11:41:20.71 |
+06:39:23.6 |
HIP 57071 |
12.81 |
| 2026-09-30 00:00 |
11:41:53.80 |
+06:35:58.5 |
HIP 57071 |
12.48 |
| 2026-09-30 12:00 |
11:42:26.91 |
+06:32:33.4 |
HIP 57136 |
11.65 |
| 2026-10-01 00:00 |
11:43:00.04 |
+06:29:08.2 |
HIP 57136 |
6.34 |
| 2026-10-01 12:00 |
11:43:33.19 |
+06:25:43.0 |
HIP 57136 |
10.18 |
| 2026-10-02 00:00 |
11:44:06.35 |
+06:22:17.8 |
HIP 57136 |
18.07 |
| 2026-10-02 12:00 |
11:44:39.54 |
+06:18:52.5 |
HIP 57380 |
22.07 |
| 2026-10-03 00:00 |
11:45:12.74 |
+06:15:27.3 |
HIP 57380 |
18.97 |
| 2026-10-03 12:00 |
11:45:45.96 |
+06:12:02.0 |
HIP 57463 |
14.70 |
| 2026-10-04 00:00 |
11:46:19.20 |
+06:08:36.8 |
HIP 57463 |
6.70 |
| 2026-10-04 12:00 |
11:46:52.46 |
+06:05:11.5 |
HIP 57463 |
5.81 |
| 2026-10-05 00:00 |
11:47:25.73 |
+06:01:46.3 |
HIP 57463 |
13.52 |
| 2026-10-05 12:00 |
11:47:59.02 |
+05:58:21.0 |
HIP 57616 |
17.50 |
| 2026-10-06 00:00 |
11:48:32.32 |
+05:54:55.8 |
HIP 57616 |
9.76 |
| 2026-10-06 12:00 |
11:49:05.64 |
+05:51:30.6 |
HIP 57616 |
6.71 |
| 2026-10-07 00:00 |
11:49:38.97 |
+05:48:05.5 |
HIP 57616 |
12.47 |
| 2026-10-07 12:00 |
11:50:12.32 |
+05:44:40.3 |
HIP 57616 |
20.67 |
| 2026-10-08 00:00 |
11:50:45.68 |
+05:41:15.3 |
HIP 57868 |
21.29 |
| 2026-10-08 12:00 |
11:51:19.06 |
+05:37:50.2 |
HIP 57868 |
12.68 |
| 2026-10-09 00:00 |
11:51:52.44 |
+05:34:25.2 |
HIP 57868 |
5.41 |
| 2026-10-09 12:00 |
11:52:25.84 |
+05:31:00.3 |
HIP 57868 |
7.69 |
| 2026-10-10 00:00 |
11:52:59.25 |
+05:27:35.4 |
HIP 57868 |
15.83 |
| 2026-10-10 12:00 |
11:53:32.68 |
+05:24:10.7 |
HIP 57868 |
24.57 |
| 2026-10-11 00:00 |
11:54:06.11 |
+05:20:45.9 |
HIP 58037 |
21.09 |