468P/Siding Spring
| Parameter |
Value |
| Designation |
468P/Siding Spring |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2023-11-23T01:26:27.240000Z |
| Orbit solution date (soln_date, UTC) |
2024-07-22T18:42:17Z |
| Obs used |
159 |
| NEO |
- |
| M1 |
11.500 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2023-07-19T08:58:28.416000Z |
| Discovery magnitude (MPC) |
19.60 V |
| Discovery observatory (MPC) |
I47 · Pierre Auger Observatory, Malargüe |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-06-10.0000000 |
| e |
0.44478834 |
| q (au) |
3.967881 |
| a (au) |
7.146610 |
| i (deg) |
50.364692 |
| Ω (om, deg) |
356.098740 |
| ω (w, deg) |
322.249960 |
| M (ma, deg) |
238.402517 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.096 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.096 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
00:22:48.28 |
+43:46:12.1 |
HIP 1871 |
11.78 |
| 2026-02-03 12:00 |
00:23:07.77 |
+43:46:30.8 |
HIP 1871 |
9.55 |
| 2026-02-04 00:00 |
00:23:27.39 |
+43:46:50.8 |
HIP 1871 |
8.29 |
| 2026-02-04 12:00 |
00:23:47.13 |
+43:47:12.3 |
HIP 1871 |
8.49 |
| 2026-02-05 00:00 |
00:24:07.00 |
+43:47:35.2 |
HIP 1871 |
10.10 |
| 2026-02-05 12:00 |
00:24:27.00 |
+43:47:59.5 |
HIP 1871 |
12.59 |
| 2026-02-06 00:00 |
00:24:47.12 |
+43:48:25.2 |
HIP 1871 |
15.58 |
| 2026-02-06 12:00 |
00:25:07.36 |
+43:48:52.3 |
HIP 1871 |
18.83 |
| 2026-02-07 00:00 |
00:25:27.72 |
+43:49:20.8 |
HIP 2059 |
22.24 |
| 2026-02-07 12:00 |
00:25:48.21 |
+43:49:50.7 |
HIP 2059 |
20.95 |
| 2026-02-08 00:00 |
00:26:08.82 |
+43:50:22.0 |
HIP 2059 |
20.25 |
| 2026-02-08 12:00 |
00:26:29.54 |
+43:50:54.7 |
HIP 2059 |
20.21 |
| 2026-02-09 00:00 |
00:26:50.39 |
+43:51:28.8 |
HIP 2059 |
20.85 |
| 2026-02-09 12:00 |
00:27:11.35 |
+43:52:04.2 |
HIP 2059 |
22.12 |
| 2026-02-10 00:00 |
00:27:32.43 |
+43:52:41.1 |
HIP 2059 |
23.93 |
| 2026-02-10 12:00 |
00:27:53.62 |
+43:53:19.3 |
HIP 2059 |
26.19 |
| 2026-02-11 00:00 |
00:28:14.93 |
+43:53:58.9 |
HIP 2059 |
28.79 |
| 2026-02-11 12:00 |
00:28:36.35 |
+43:54:39.9 |
HIP 2455 |
28.27 |
| 2026-02-12 00:00 |
00:28:57.88 |
+43:55:22.3 |
HIP 2455 |
24.35 |
| 2026-02-12 12:00 |
00:29:19.53 |
+43:56:06.0 |
HIP 2455 |
20.42 |
| 2026-02-13 00:00 |
00:29:41.28 |
+43:56:51.1 |
HIP 2455 |
16.49 |
| 2026-02-13 12:00 |
00:30:03.15 |
+43:57:37.5 |
HIP 2455 |
12.58 |
| 2026-02-14 00:00 |
00:30:25.12 |
+43:58:25.4 |
HIP 2455 |
8.75 |
| 2026-02-14 12:00 |
00:30:47.21 |
+43:59:14.6 |
HIP 2455 |
5.23 |
| 2026-02-15 00:00 |
00:31:09.40 |
+44:00:05.1 |
HIP 2455 |
3.35 |
| 2026-02-15 12:00 |
00:31:31.69 |
+44:00:57.0 |
HIP 2455 |
5.36 |
| 2026-02-16 00:00 |
00:31:54.09 |
+44:01:50.2 |
HIP 2455 |
8.96 |
| 2026-02-16 12:00 |
00:32:16.59 |
+44:02:44.8 |
HIP 2455 |
12.91 |
| 2026-02-17 00:00 |
00:32:39.20 |
+44:03:40.7 |
HIP 2455 |
16.98 |
| 2026-02-17 12:00 |
00:33:01.90 |
+44:04:38.0 |
HIP 2455 |
21.11 |
| 2026-02-18 00:00 |
00:33:24.71 |
+44:05:36.6 |
HIP 2455 |
25.28 |
| 2026-02-18 12:00 |
00:33:47.62 |
+44:06:36.5 |
HIP 2837 |
24.10 |
| 2026-02-19 00:00 |
00:34:10.62 |
+44:07:37.7 |
HIP 2837 |
20.32 |
| 2026-02-19 12:00 |
00:34:33.73 |
+44:08:40.3 |
HIP 2837 |
16.77 |
| 2026-02-20 00:00 |
00:34:56.93 |
+44:09:44.1 |
HIP 2837 |
13.64 |
| 2026-02-20 12:00 |
00:35:20.22 |
+44:10:49.3 |
HIP 2837 |
11.32 |
| 2026-02-21 00:00 |
00:35:43.61 |
+44:11:55.8 |
HIP 2837 |
10.39 |
| 2026-02-21 12:00 |
00:36:07.09 |
+44:13:03.6 |
HIP 2837 |
11.23 |
| 2026-02-22 00:00 |
00:36:30.67 |
+44:14:12.7 |
HIP 2837 |
13.52 |
| 2026-02-22 12:00 |
00:36:54.33 |
+44:15:23.0 |
HIP 2900 |
14.00 |
| 2026-02-23 00:00 |
00:37:18.09 |
+44:16:34.7 |
HIP 2900 |
13.93 |
| 2026-02-23 12:00 |
00:37:41.93 |
+44:17:47.6 |
HIP 2900 |
15.19 |
| 2026-02-24 00:00 |
00:38:05.87 |
+44:19:01.8 |
HIP 2900 |
17.52 |