| 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 · University of Arizona 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 |
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) |
| 2026-07-29 00:00 |
10:36:19.04 |
+04:04:26.2 |
HIP 51941 |
9.27 |
| 2026-07-29 12:00 |
10:36:38.45 |
+04:02:29.8 |
HIP 51941 |
5.55 |
| 2026-07-30 00:00 |
10:36:57.89 |
+04:00:32.9 |
HIP 51941 |
5.49 |
| 2026-07-30 12:00 |
10:37:17.38 |
+03:58:35.5 |
HIP 51941 |
9.18 |
| 2026-07-31 00:00 |
10:37:36.91 |
+03:56:37.8 |
HIP 51941 |
13.91 |
| 2026-07-31 12:00 |
10:37:56.47 |
+03:54:39.6 |
HIP 51941 |
18.93 |
| 2026-08-01 00:00 |
10:38:16.07 |
+03:52:41.0 |
HIP 51941 |
24.06 |
| 2026-08-01 12:00 |
10:38:35.71 |
+03:50:42.0 |
HIP 52055 |
26.44 |
| 2026-08-02 00:00 |
10:38:55.39 |
+03:48:42.6 |
HIP 52055 |
26.01 |
| 2026-08-02 12:00 |
10:39:15.10 |
+03:46:42.8 |
HIP 52243 |
23.30 |
| 2026-08-03 00:00 |
10:39:34.85 |
+03:44:42.6 |
HIP 52243 |
21.41 |
| 2026-08-03 12:00 |
10:39:54.64 |
+03:42:41.9 |
HIP 52285 |
18.16 |
| 2026-08-04 00:00 |
10:40:14.46 |
+03:40:40.9 |
HIP 52285 |
12.82 |
| 2026-08-04 12:00 |
10:40:34.31 |
+03:38:39.5 |
HIP 52285 |
7.47 |
| 2026-08-05 00:00 |
10:40:54.20 |
+03:36:37.7 |
HIP 52285 |
2.10 |
| 2026-08-05 12:00 |
10:41:14.12 |
+03:34:35.5 |
HIP 52285 |
3.27 |
| 2026-08-06 00:00 |
10:41:34.08 |
+03:32:32.8 |
HIP 52285 |
8.65 |
| 2026-08-06 12:00 |
10:41:54.06 |
+03:30:29.9 |
HIP 52401 |
11.74 |
| 2026-08-07 00:00 |
10:42:14.08 |
+03:28:26.5 |
HIP 52401 |
8.77 |
| 2026-08-07 12:00 |
10:42:34.13 |
+03:26:22.7 |
HIP 52401 |
8.64 |
| 2026-08-08 00:00 |
10:42:54.22 |
+03:24:18.6 |
HIP 52401 |
11.46 |
| 2026-08-08 12:00 |
10:43:14.33 |
+03:22:14.1 |
HIP 52501 |
15.57 |
| 2026-08-09 00:00 |
10:43:34.47 |
+03:20:09.2 |
HIP 52501 |
10.29 |
| 2026-08-09 12:00 |
10:43:54.64 |
+03:18:03.9 |
HIP 52501 |
5.35 |
| 2026-08-10 00:00 |
10:44:14.84 |
+03:15:58.3 |
HIP 52501 |
3.28 |
| 2026-08-10 12:00 |
10:44:35.07 |
+03:13:52.3 |
HIP 52501 |
7.25 |
| 2026-08-11 00:00 |
10:44:55.32 |
+03:11:46.0 |
HIP 52574 |
6.86 |
| 2026-08-11 12:00 |
10:45:15.60 |
+03:09:39.2 |
HIP 52574 |
9.37 |
| 2026-08-12 00:00 |
10:45:35.91 |
+03:07:32.2 |
HIP 52574 |
13.74 |
| 2026-08-12 12:00 |
10:45:56.24 |
+03:05:24.8 |
HIP 52574 |
18.73 |
| 2026-08-13 00:00 |
10:46:16.60 |
+03:03:17.0 |
HIP 52574 |
23.95 |
| 2026-08-13 12:00 |
10:46:36.98 |
+03:01:09.0 |
HIP 52774 |
28.20 |
| 2026-08-14 00:00 |
10:46:57.39 |
+02:59:00.5 |
HIP 52774 |
24.41 |
| 2026-08-14 12:00 |
10:47:17.82 |
+02:56:51.8 |
HIP 52821 |
20.41 |
| 2026-08-15 00:00 |
10:47:38.26 |
+02:54:42.7 |
HIP 52821 |
16.34 |
| 2026-08-15 12:00 |
10:47:58.74 |
+02:52:33.3 |
HIP 52821 |
13.36 |
| 2026-08-16 00:00 |
10:48:19.23 |
+02:50:23.6 |
HIP 52821 |
12.32 |
| 2026-08-16 12:00 |
10:48:39.74 |
+02:48:13.5 |
HIP 52821 |
13.66 |
| 2026-08-17 00:00 |
10:49:00.27 |
+02:46:03.2 |
HIP 52821 |
16.84 |
| 2026-08-17 12:00 |
10:49:20.82 |
+02:43:52.5 |
HIP 52821 |
21.04 |
| 2026-08-18 00:00 |
10:49:41.39 |
+02:41:41.5 |
HIP 53047 |
22.68 |
| 2026-08-18 12:00 |
10:50:01.98 |
+02:39:30.2 |
HIP 53047 |
17.78 |
| 2026-08-19 00:00 |
10:50:22.58 |
+02:37:18.7 |
HIP 53047 |
13.42 |