| Parameter |
Value |
| Designation |
162P/Siding Spring |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2010-03-08T10:39:21.401280Z |
| Orbit solution date (soln_date, UTC) |
2026-09-21T07:12:14Z |
| Obs used |
3269 |
| NEO |
Yes |
| M1 |
15.200 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-01-31.0000000 |
| e |
0.59607221 |
| q (au) |
1.233398 |
| a (au) |
3.053512 |
| i (deg) |
27.817211 |
| Ω (om, deg) |
31.235812 |
| ω (w, deg) |
356.335111 |
| M (ma, deg) |
60.689566 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.800 + 2.201\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.800 |
| n |
2.201 |
| gf |
0.927 |
| gb |
-0.819 |
| k |
0.984 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
09:27:52.66 |
+36:52:31.1 |
HIP 46368 |
24.92 |
| 2026-09-20 12:00 |
09:29:11.52 |
+36:50:28.9 |
HIP 46368 |
31.66 |
| 2026-09-21 00:00 |
09:30:30.05 |
+36:48:26.0 |
HIP 46749 |
26.94 |
| 2026-09-21 12:00 |
09:31:48.25 |
+36:46:22.4 |
HIP 46749 |
20.66 |
| 2026-09-22 00:00 |
09:33:06.13 |
+36:44:18.2 |
HIP 46904 |
15.84 |
| 2026-09-22 12:00 |
09:34:23.67 |
+36:42:13.4 |
HIP 46904 |
16.84 |
| 2026-09-23 00:00 |
09:35:40.89 |
+36:40:08.0 |
HIP 47030 |
18.89 |
| 2026-09-23 12:00 |
09:36:57.78 |
+36:38:02.2 |
HIP 47244 |
10.40 |
| 2026-09-24 00:00 |
09:38:14.35 |
+36:35:55.8 |
HIP 47244 |
5.25 |
| 2026-09-24 12:00 |
09:39:30.59 |
+36:33:49.1 |
HIP 47244 |
20.63 |
| 2026-09-25 00:00 |
09:40:46.50 |
+36:31:41.9 |
HIP 47716 |
35.64 |
| 2026-09-25 12:00 |
09:42:02.09 |
+36:29:34.3 |
HIP 47716 |
20.33 |
| 2026-09-26 00:00 |
09:43:17.35 |
+36:27:26.4 |
HIP 47716 |
5.28 |
| 2026-09-26 12:00 |
09:44:32.29 |
+36:25:18.2 |
HIP 47845 |
7.34 |
| 2026-09-27 00:00 |
09:45:46.91 |
+36:23:09.7 |
HIP 47845 |
8.28 |
| 2026-09-27 12:00 |
09:47:01.20 |
+36:21:01.0 |
HIP 47845 |
23.25 |
| 2026-09-28 00:00 |
09:48:15.17 |
+36:18:52.2 |
HIP 48173 |
16.87 |
| 2026-09-28 12:00 |
09:49:28.82 |
+36:16:43.1 |
HIP 48173 |
15.60 |
| 2026-09-29 00:00 |
09:50:42.15 |
+36:14:33.9 |
HIP 48337 |
15.77 |
| 2026-09-29 12:00 |
09:51:55.15 |
+36:12:24.7 |
HIP 48421 |
7.06 |
| 2026-09-30 00:00 |
09:53:07.84 |
+36:10:15.3 |
HIP 48546 |
12.33 |
| 2026-09-30 12:00 |
09:54:20.20 |
+36:08:06.0 |
HIP 48546 |
7.22 |
| 2026-10-01 00:00 |
09:55:32.24 |
+36:05:56.7 |
HIP 48546 |
19.64 |
| 2026-10-01 12:00 |
09:56:43.97 |
+36:03:47.4 |
HIP 48546 |
33.88 |
| 2026-10-02 00:00 |
09:57:55.37 |
+36:01:38.3 |
HIP 49056 |
35.10 |
| 2026-10-02 12:00 |
09:59:06.46 |
+35:59:29.2 |
HIP 49056 |
21.19 |
| 2026-10-03 00:00 |
10:00:17.22 |
+35:57:20.3 |
HIP 49056 |
9.50 |
| 2026-10-03 12:00 |
10:01:27.67 |
+35:55:11.6 |
HIP 49056 |
12.25 |
| 2026-10-04 00:00 |
10:02:37.79 |
+35:53:03.2 |
HIP 49283 |
12.31 |
| 2026-10-04 12:00 |
10:03:47.60 |
+35:50:55.0 |
HIP 49283 |
6.84 |
| 2026-10-05 00:00 |
10:04:57.09 |
+35:48:47.1 |
HIP 49283 |
18.67 |
| 2026-10-05 12:00 |
10:06:06.26 |
+35:46:39.6 |
HIP 49640 |
25.13 |
| 2026-10-06 00:00 |
10:07:15.11 |
+35:44:32.4 |
HIP 49640 |
12.78 |
| 2026-10-06 12:00 |
10:08:23.65 |
+35:42:25.6 |
HIP 49640 |
9.73 |
| 2026-10-07 00:00 |
10:09:31.86 |
+35:40:19.3 |
HIP 49687 |
19.12 |
| 2026-10-07 12:00 |
10:10:39.76 |
+35:38:13.4 |
HIP 49687 |
30.75 |
| 2026-10-08 00:00 |
10:11:47.33 |
+35:36:08.1 |
HIP 50050 |
19.78 |
| 2026-10-08 12:00 |
10:12:54.59 |
+35:34:03.3 |
HIP 50050 |
9.39 |
| 2026-10-09 00:00 |
10:14:01.53 |
+35:31:59.1 |
HIP 50050 |
12.94 |
| 2026-10-09 12:00 |
10:15:08.15 |
+35:29:55.5 |
HIP 50293 |
23.62 |
| 2026-10-10 00:00 |
10:16:14.46 |
+35:27:52.5 |
HIP 50293 |
18.03 |
| 2026-10-10 12:00 |
10:17:20.44 |
+35:25:50.2 |
HIP 50464 |
21.14 |
| 2026-10-11 00:00 |
10:18:26.11 |
+35:23:48.5 |
HIP 50464 |
20.52 |