| 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) |
| 2026-05-12 00:00 |
01:49:43.58 |
+50:49:14.4 |
HIP 8333 |
21.75 |
| 2026-05-12 12:00 |
01:50:12.92 |
+50:52:45.4 |
HIP 8714 |
19.10 |
| 2026-05-13 00:00 |
01:50:42.26 |
+50:56:16.9 |
HIP 8714 |
16.27 |
| 2026-05-13 12:00 |
01:51:11.57 |
+50:59:49.0 |
HIP 8696 |
13.81 |
| 2026-05-14 00:00 |
01:51:40.88 |
+51:03:21.7 |
HIP 8696 |
8.79 |
| 2026-05-14 12:00 |
01:52:10.17 |
+51:06:54.9 |
HIP 8696 |
5.60 |
| 2026-05-15 00:00 |
01:52:39.45 |
+51:10:28.6 |
HIP 8696 |
7.25 |
| 2026-05-15 12:00 |
01:53:08.70 |
+51:14:02.9 |
HIP 8696 |
11.88 |
| 2026-05-16 00:00 |
01:53:37.94 |
+51:17:37.7 |
HIP 8771 |
13.12 |
| 2026-05-16 12:00 |
01:54:07.17 |
+51:21:13.0 |
HIP 8771 |
13.96 |
| 2026-05-17 00:00 |
01:54:36.37 |
+51:24:48.9 |
HIP 8771 |
16.87 |
| 2026-05-17 12:00 |
01:55:05.55 |
+51:28:25.3 |
HIP 8984 |
14.38 |
| 2026-05-18 00:00 |
01:55:34.72 |
+51:32:02.2 |
HIP 8984 |
9.44 |
| 2026-05-18 12:00 |
01:56:03.86 |
+51:35:39.7 |
HIP 8984 |
6.22 |
| 2026-05-19 00:00 |
01:56:32.98 |
+51:39:17.6 |
HIP 8984 |
7.43 |
| 2026-05-19 12:00 |
01:57:02.07 |
+51:42:56.1 |
HIP 8984 |
11.77 |
| 2026-05-20 00:00 |
01:57:31.15 |
+51:46:35.0 |
HIP 9203 |
10.91 |
| 2026-05-20 12:00 |
01:58:00.19 |
+51:50:14.5 |
HIP 9203 |
5.12 |
| 2026-05-21 00:00 |
01:58:29.22 |
+51:53:54.5 |
HIP 9203 |
0.69 |
| 2026-05-21 12:00 |
01:58:58.21 |
+51:57:34.9 |
HIP 9203 |
6.46 |
| 2026-05-22 00:00 |
01:59:27.18 |
+52:01:15.8 |
HIP 9203 |
12.24 |
| 2026-05-22 12:00 |
01:59:56.12 |
+52:04:57.3 |
HIP 9203 |
18.02 |
| 2026-05-23 00:00 |
02:00:25.03 |
+52:08:39.2 |
HIP 9203 |
23.80 |
| 2026-05-23 12:00 |
02:00:53.92 |
+52:12:21.6 |
HIP 9482 |
28.74 |
| 2026-05-24 00:00 |
02:01:22.77 |
+52:16:04.4 |
HIP 9482 |
23.90 |
| 2026-05-24 12:00 |
02:01:51.59 |
+52:19:47.7 |
HIP 9482 |
19.55 |
| 2026-05-25 00:00 |
02:02:20.39 |
+52:23:31.5 |
HIP 9482 |
16.10 |
| 2026-05-25 12:00 |
02:02:49.15 |
+52:27:15.8 |
HIP 9482 |
14.22 |
| 2026-05-26 00:00 |
02:03:17.88 |
+52:31:00.5 |
HIP 9482 |
14.52 |
| 2026-05-26 12:00 |
02:03:46.57 |
+52:34:45.7 |
HIP 9482 |
16.89 |
| 2026-05-27 00:00 |
02:04:15.23 |
+52:38:31.3 |
HIP 9482 |
20.61 |
| 2026-05-27 12:00 |
02:04:43.86 |
+52:42:17.4 |
HIP 9482 |
25.10 |
| 2026-05-28 00:00 |
02:05:12.46 |
+52:46:03.9 |
HIP 9542 |
29.73 |
| 2026-05-28 12:00 |
02:05:41.01 |
+52:49:50.9 |
HIP 9992 |
27.47 |
| 2026-05-29 00:00 |
02:06:09.53 |
+52:53:38.3 |
HIP 9992 |
22.89 |
| 2026-05-29 12:00 |
02:06:38.02 |
+52:57:26.2 |
HIP 9992 |
18.98 |
| 2026-05-30 00:00 |
02:07:06.46 |
+53:01:14.5 |
HIP 9992 |
16.22 |
| 2026-05-30 12:00 |
02:07:34.87 |
+53:05:03.2 |
HIP 9992 |
15.23 |
| 2026-05-31 00:00 |
02:08:03.24 |
+53:08:52.4 |
HIP 9992 |
16.34 |
| 2026-05-31 12:00 |
02:08:31.57 |
+53:12:42.0 |
HIP 10159 |
19.03 |
| 2026-06-01 00:00 |
02:08:59.86 |
+53:16:32.1 |
HIP 10159 |
15.23 |
| 2026-06-01 12:00 |
02:09:28.11 |
+53:20:22.6 |
HIP 10159 |
12.94 |
| 2026-06-02 00:00 |
02:09:56.31 |
+53:24:13.5 |
HIP 10159 |
12.99 |