| Parameter |
Value |
| Designation |
485P/Sheppard-Tholen |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2005-10-10T02:23:33.267840Z |
| Orbit solution date (soln_date, UTC) |
2024-10-10T17:21:52Z |
| Obs used |
12 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
19.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2006-01-02T08:50:54.816000Z |
| Discovery magnitude (MPC) |
20.30 V |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2009-04-12.0000000 |
| e |
0.41586197 |
| q (au) |
3.995838 |
| a (au) |
6.840572 |
| i (deg) |
10.009723 |
| Ω (om, deg) |
261.841751 |
| ω (w, deg) |
195.918921 |
| M (ma, deg) |
70.508521 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.234 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.234 |
| n |
6.000 |
| gf |
0.938 |
| gb |
-0.857 |
| k |
1.000 |
| δ90 |
3.014 |
| 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 |
12:42:05.57 |
-15:31:18.8 |
HIP 61922 |
10.32 |
| 2026-05-12 12:00 |
12:41:57.97 |
-15:29:45.2 |
HIP 61922 |
8.06 |
| 2026-05-13 00:00 |
12:41:50.50 |
-15:28:12.0 |
HIP 61922 |
5.95 |
| 2026-05-13 12:00 |
12:41:43.17 |
-15:26:39.3 |
HIP 61922 |
4.17 |
| 2026-05-14 00:00 |
12:41:35.97 |
-15:25:07.1 |
HIP 61922 |
3.24 |
| 2026-05-14 12:00 |
12:41:28.90 |
-15:23:35.4 |
HIP 61922 |
3.79 |
| 2026-05-15 00:00 |
12:41:21.96 |
-15:22:04.2 |
HIP 61922 |
5.34 |
| 2026-05-15 12:00 |
12:41:15.17 |
-15:20:33.5 |
HIP 61922 |
7.26 |
| 2026-05-16 00:00 |
12:41:08.50 |
-15:19:03.3 |
HIP 61922 |
9.29 |
| 2026-05-16 12:00 |
12:41:01.98 |
-15:17:33.8 |
HIP 61922 |
11.36 |
| 2026-05-17 00:00 |
12:40:55.59 |
-15:16:04.7 |
HIP 61922 |
13.43 |
| 2026-05-17 12:00 |
12:40:49.34 |
-15:14:36.3 |
HIP 61922 |
15.50 |
| 2026-05-18 00:00 |
12:40:43.23 |
-15:13:08.4 |
HIP 61922 |
17.55 |
| 2026-05-18 12:00 |
12:40:37.26 |
-15:11:41.1 |
HIP 61922 |
19.57 |
| 2026-05-19 00:00 |
12:40:31.43 |
-15:10:14.4 |
HIP 61922 |
21.57 |
| 2026-05-19 12:00 |
12:40:25.74 |
-15:08:48.3 |
HIP 61922 |
23.55 |
| 2026-05-20 00:00 |
12:40:20.20 |
-15:07:22.9 |
HIP 61922 |
25.50 |
| 2026-05-20 12:00 |
12:40:14.79 |
-15:05:58.1 |
HIP 61922 |
27.41 |
| 2026-05-21 00:00 |
12:40:09.53 |
-15:04:33.9 |
HIP 61922 |
29.30 |
| 2026-05-21 12:00 |
12:40:04.42 |
-15:03:10.4 |
HIP 61922 |
31.16 |
| 2026-05-22 00:00 |
12:39:59.44 |
-15:01:47.6 |
HIP 61922 |
32.99 |
| 2026-05-22 12:00 |
12:39:54.61 |
-15:00:25.4 |
HIP 61922 |
34.79 |
| 2026-05-23 00:00 |
12:39:49.93 |
-14:59:04.0 |
HIP 61993 |
36.15 |
| 2026-05-23 12:00 |
12:39:45.39 |
-14:57:43.2 |
HIP 61993 |
37.47 |
| 2026-05-24 00:00 |
12:39:40.99 |
-14:56:23.1 |
HIP 61993 |
38.79 |
| 2026-05-24 12:00 |
12:39:36.74 |
-14:55:03.7 |
HIP 61993 |
40.10 |
| 2026-05-25 00:00 |
12:39:32.64 |
-14:53:45.0 |
HIP 61993 |
41.40 |
| 2026-05-25 12:00 |
12:39:28.68 |
-14:52:27.0 |
HIP 61993 |
42.69 |
| 2026-05-26 00:00 |
12:39:24.86 |
-14:51:09.8 |
HIP 61993 |
43.96 |
| 2026-05-26 12:00 |
12:39:21.20 |
-14:49:53.3 |
HIP 61993 |
45.21 |
| 2026-05-27 00:00 |
12:39:17.68 |
-14:48:37.6 |
HIP 61993 |
46.45 |
| 2026-05-27 12:00 |
12:39:14.30 |
-14:47:22.6 |
HIP 61853 |
45.88 |
| 2026-05-28 00:00 |
12:39:11.08 |
-14:46:08.3 |
HIP 61651 |
44.48 |
| 2026-05-28 12:00 |
12:39:07.99 |
-14:44:54.8 |
HIP 61651 |
43.10 |
| 2026-05-29 00:00 |
12:39:05.06 |
-14:43:42.1 |
HIP 61651 |
41.73 |
| 2026-05-29 12:00 |
12:39:02.27 |
-14:42:30.1 |
HIP 61651 |
40.40 |
| 2026-05-30 00:00 |
12:38:59.63 |
-14:41:19.0 |
HIP 61651 |
39.08 |
| 2026-05-30 12:00 |
12:38:57.14 |
-14:40:08.6 |
HIP 61651 |
37.79 |
| 2026-05-31 00:00 |
12:38:54.80 |
-14:38:59.0 |
HIP 61651 |
36.53 |
| 2026-05-31 12:00 |
12:38:52.60 |
-14:37:50.2 |
HIP 61651 |
35.29 |
| 2026-06-01 00:00 |
12:38:50.55 |
-14:36:42.2 |
HIP 61651 |
34.07 |
| 2026-06-01 12:00 |
12:38:48.64 |
-14:35:35.0 |
HIP 61651 |
32.87 |
| 2026-06-02 00:00 |
12:38:46.88 |
-14:34:28.6 |
HIP 61651 |
31.70 |