| Parameter |
Value |
| Designation |
447P/Sheppard-Tholen |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2022-08-01T11:34:43.152960Z |
| Orbit solution date (soln_date, UTC) |
2022-12-23T17:43:31Z |
| Obs used |
75 |
| NEO |
- |
| M1 |
7.600 |
| K1 |
16.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2008-10-09T08:24:27.648000Z |
| Discovery magnitude (MPC) |
22.60 V |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-05-24.0000000 |
| e |
0.18072317 |
| q (au) |
4.665883 |
| a (au) |
5.695124 |
| i (deg) |
7.414149 |
| Ω (om, deg) |
302.834446 |
| ω (w, deg) |
95.085999 |
| M (ma, deg) |
222.542292 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.659 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.659 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-0.773 |
| 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) |
| 2026-03-26 00:00 |
10:05:30.18 |
+06:32:41.4 |
HIP 49519 |
27.35 |
| 2026-03-26 12:00 |
10:05:20.47 |
+06:33:36.2 |
HIP 49519 |
28.21 |
| 2026-03-27 00:00 |
10:05:10.90 |
+06:34:30.4 |
HIP 49519 |
29.26 |
| 2026-03-27 12:00 |
10:05:01.45 |
+06:35:24.1 |
HIP 49519 |
30.45 |
| 2026-03-28 00:00 |
10:04:52.14 |
+06:36:17.3 |
HIP 49519 |
31.78 |
| 2026-03-28 12:00 |
10:04:42.97 |
+06:37:09.9 |
HIP 49519 |
33.22 |
| 2026-03-29 00:00 |
10:04:33.93 |
+06:38:02.0 |
HIP 49316 |
33.62 |
| 2026-03-29 12:00 |
10:04:25.02 |
+06:38:53.5 |
HIP 49316 |
32.29 |
| 2026-03-30 00:00 |
10:04:16.26 |
+06:39:44.4 |
HIP 49316 |
31.10 |
| 2026-03-30 12:00 |
10:04:07.63 |
+06:40:34.8 |
HIP 49316 |
30.06 |
| 2026-03-31 00:00 |
10:03:59.14 |
+06:41:24.5 |
HIP 49316 |
29.16 |
| 2026-03-31 12:00 |
10:03:50.79 |
+06:42:13.7 |
HIP 49316 |
28.43 |
| 2026-04-01 00:00 |
10:03:42.59 |
+06:43:02.3 |
HIP 49316 |
27.86 |
| 2026-04-01 12:00 |
10:03:34.52 |
+06:43:50.3 |
HIP 49316 |
27.46 |
| 2026-04-02 00:00 |
10:03:26.60 |
+06:44:37.6 |
HIP 49316 |
27.22 |
| 2026-04-02 12:00 |
10:03:18.83 |
+06:45:24.4 |
HIP 49316 |
27.15 |
| 2026-04-03 00:00 |
10:03:11.19 |
+06:46:10.5 |
HIP 49316 |
27.22 |
| 2026-04-03 12:00 |
10:03:03.71 |
+06:46:56.0 |
HIP 49316 |
27.44 |
| 2026-04-04 00:00 |
10:02:56.37 |
+06:47:40.9 |
HIP 49316 |
27.79 |
| 2026-04-04 12:00 |
10:02:49.17 |
+06:48:25.1 |
HIP 49316 |
28.25 |
| 2026-04-05 00:00 |
10:02:42.13 |
+06:49:08.7 |
HIP 49316 |
28.83 |
| 2026-04-05 12:00 |
10:02:35.23 |
+06:49:51.6 |
HIP 49316 |
29.49 |
| 2026-04-06 00:00 |
10:02:28.48 |
+06:50:33.9 |
HIP 49100 |
28.38 |
| 2026-04-06 12:00 |
10:02:21.89 |
+06:51:15.5 |
HIP 49100 |
26.83 |
| 2026-04-07 00:00 |
10:02:15.44 |
+06:51:56.5 |
HIP 49100 |
25.33 |
| 2026-04-07 12:00 |
10:02:09.15 |
+06:52:36.7 |
HIP 49100 |
23.90 |
| 2026-04-08 00:00 |
10:02:03.00 |
+06:53:16.3 |
HIP 49100 |
22.54 |
| 2026-04-08 12:00 |
10:01:57.01 |
+06:53:55.2 |
HIP 49100 |
21.24 |
| 2026-04-09 00:00 |
10:01:51.18 |
+06:54:33.4 |
HIP 49100 |
20.02 |
| 2026-04-09 12:00 |
10:01:45.50 |
+06:55:10.9 |
HIP 49100 |
18.88 |
| 2026-04-10 00:00 |
10:01:39.97 |
+06:55:47.7 |
HIP 49100 |
17.82 |
| 2026-04-10 12:00 |
10:01:34.60 |
+06:56:23.8 |
HIP 49100 |
16.85 |
| 2026-04-11 00:00 |
10:01:29.38 |
+06:56:59.2 |
HIP 49100 |
15.98 |
| 2026-04-11 12:00 |
10:01:24.32 |
+06:57:33.9 |
HIP 49100 |
15.21 |
| 2026-04-12 00:00 |
10:01:19.42 |
+06:58:07.8 |
HIP 49100 |
14.54 |
| 2026-04-12 12:00 |
10:01:14.67 |
+06:58:41.1 |
HIP 49100 |
13.98 |
| 2026-04-13 00:00 |
10:01:10.09 |
+06:59:13.6 |
HIP 49100 |
13.53 |
| 2026-04-13 12:00 |
10:01:05.66 |
+06:59:45.3 |
HIP 49100 |
13.18 |
| 2026-04-14 00:00 |
10:01:01.39 |
+07:00:16.3 |
HIP 49100 |
12.95 |
| 2026-04-14 12:00 |
10:00:57.28 |
+07:00:46.6 |
HIP 49100 |
12.81 |
| 2026-04-15 00:00 |
10:00:53.33 |
+07:01:16.1 |
HIP 49100 |
12.77 |
| 2026-04-15 12:00 |
10:00:49.54 |
+07:01:44.8 |
HIP 49100 |
12.81 |
| 2026-04-16 00:00 |
10:00:45.91 |
+07:02:12.8 |
HIP 49100 |
12.93 |