| Parameter |
Value |
| Designation |
P/2006 HR30 (Siding Spring) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2007-01-02T06:46:18.693120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:56Z |
| Obs used |
3059 |
| NEO |
Yes |
| M1 |
13.900 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2006-11-07.0000000 |
| e |
0.84311855 |
| q (au) |
1.226428 |
| a (au) |
7.817544 |
| i (deg) |
31.884499 |
| Ω (om, deg) |
309.952160 |
| ω (w, deg) |
117.413876 |
| M (ma, deg) |
357.462130 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.237 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.237 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.665 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
19:44:58.37 |
-37:29:45.7 |
HIP 97067 |
16.22 |
| 2026-05-12 12:00 |
19:44:53.21 |
-37:30:33.9 |
HIP 97067 |
15.09 |
| 2026-05-13 00:00 |
19:44:47.88 |
-37:31:22.2 |
HIP 97067 |
13.96 |
| 2026-05-13 12:00 |
19:44:42.38 |
-37:32:10.8 |
HIP 97067 |
12.84 |
| 2026-05-14 00:00 |
19:44:36.70 |
-37:32:59.5 |
HIP 97067 |
11.73 |
| 2026-05-14 12:00 |
19:44:30.86 |
-37:33:48.3 |
HIP 97067 |
10.66 |
| 2026-05-15 00:00 |
19:44:24.83 |
-37:34:37.3 |
HIP 97067 |
9.64 |
| 2026-05-15 12:00 |
19:44:18.64 |
-37:35:26.4 |
HIP 97067 |
8.71 |
| 2026-05-16 00:00 |
19:44:12.27 |
-37:36:15.7 |
HIP 97067 |
7.92 |
| 2026-05-16 12:00 |
19:44:05.73 |
-37:37:05.0 |
HIP 97067 |
7.33 |
| 2026-05-17 00:00 |
19:43:59.02 |
-37:37:54.5 |
HIP 97067 |
7.01 |
| 2026-05-17 12:00 |
19:43:52.14 |
-37:38:44.0 |
HIP 97067 |
7.03 |
| 2026-05-18 00:00 |
19:43:45.08 |
-37:39:33.7 |
HIP 97067 |
7.39 |
| 2026-05-18 12:00 |
19:43:37.85 |
-37:40:23.4 |
HIP 97067 |
8.07 |
| 2026-05-19 00:00 |
19:43:30.45 |
-37:41:13.2 |
HIP 97067 |
9.01 |
| 2026-05-19 12:00 |
19:43:22.88 |
-37:42:03.1 |
HIP 97067 |
10.16 |
| 2026-05-20 00:00 |
19:43:15.13 |
-37:42:53.0 |
HIP 97067 |
11.46 |
| 2026-05-20 12:00 |
19:43:07.22 |
-37:43:42.9 |
HIP 97067 |
12.88 |
| 2026-05-21 00:00 |
19:42:59.14 |
-37:44:32.9 |
HIP 97067 |
14.40 |
| 2026-05-21 12:00 |
19:42:50.88 |
-37:45:22.9 |
HIP 97067 |
16.00 |
| 2026-05-22 00:00 |
19:42:42.46 |
-37:46:13.0 |
HIP 97067 |
17.67 |
| 2026-05-22 12:00 |
19:42:33.87 |
-37:47:03.0 |
HIP 97067 |
19.39 |
| 2026-05-23 00:00 |
19:42:25.11 |
-37:47:53.0 |
HIP 97067 |
21.17 |
| 2026-05-23 12:00 |
19:42:16.19 |
-37:48:43.1 |
HIP 97067 |
22.99 |
| 2026-05-24 00:00 |
19:42:07.09 |
-37:49:33.1 |
HIP 97067 |
24.85 |
| 2026-05-24 12:00 |
19:41:57.83 |
-37:50:23.0 |
HIP 97000 |
26.58 |
| 2026-05-25 00:00 |
19:41:48.41 |
-37:51:13.0 |
HIP 96768 |
25.27 |
| 2026-05-25 12:00 |
19:41:38.81 |
-37:52:02.9 |
HIP 96768 |
23.31 |
| 2026-05-26 00:00 |
19:41:29.06 |
-37:52:52.7 |
HIP 96768 |
21.35 |
| 2026-05-26 12:00 |
19:41:19.14 |
-37:53:42.5 |
HIP 96768 |
19.39 |
| 2026-05-27 00:00 |
19:41:09.05 |
-37:54:32.2 |
HIP 96768 |
17.46 |
| 2026-05-27 12:00 |
19:40:58.80 |
-37:55:21.8 |
HIP 96768 |
15.56 |
| 2026-05-28 00:00 |
19:40:48.39 |
-37:56:11.3 |
HIP 96768 |
13.73 |
| 2026-05-28 12:00 |
19:40:37.82 |
-37:57:00.7 |
HIP 96768 |
12.02 |
| 2026-05-29 00:00 |
19:40:27.08 |
-37:57:50.0 |
HIP 96768 |
10.51 |
| 2026-05-29 12:00 |
19:40:16.19 |
-37:58:39.2 |
HIP 96768 |
9.30 |
| 2026-05-30 00:00 |
19:40:05.13 |
-37:59:28.2 |
HIP 96768 |
8.56 |
| 2026-05-30 12:00 |
19:39:53.92 |
-38:00:17.1 |
HIP 96768 |
8.44 |
| 2026-05-31 00:00 |
19:39:42.54 |
-38:01:05.8 |
HIP 96768 |
8.97 |
| 2026-05-31 12:00 |
19:39:31.01 |
-38:01:54.4 |
HIP 96768 |
10.09 |
| 2026-06-01 00:00 |
19:39:19.32 |
-38:02:42.8 |
HIP 96768 |
11.63 |
| 2026-06-01 12:00 |
19:39:07.47 |
-38:03:31.1 |
HIP 96768 |
13.47 |
| 2026-06-02 00:00 |
19:38:55.47 |
-38:04:19.1 |
HIP 96768 |
15.51 |