| 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) |
| 2026-05-12 00:00 |
10:01:17.84 |
+07:08:03.9 |
HIP 49100 |
4.60 |
| 2026-05-12 12:00 |
10:01:22.58 |
+07:07:49.1 |
HIP 49100 |
5.05 |
| 2026-05-13 00:00 |
10:01:27.46 |
+07:07:33.4 |
HIP 49100 |
5.76 |
| 2026-05-13 12:00 |
10:01:32.49 |
+07:07:16.9 |
HIP 49100 |
6.65 |
| 2026-05-14 00:00 |
10:01:37.66 |
+07:06:59.6 |
HIP 49100 |
7.69 |
| 2026-05-14 12:00 |
10:01:42.99 |
+07:06:41.4 |
HIP 49100 |
8.84 |
| 2026-05-15 00:00 |
10:01:48.46 |
+07:06:22.4 |
HIP 49100 |
10.08 |
| 2026-05-15 12:00 |
10:01:54.07 |
+07:06:02.7 |
HIP 49100 |
11.39 |
| 2026-05-16 00:00 |
10:01:59.84 |
+07:05:42.1 |
HIP 49100 |
12.77 |
| 2026-05-16 12:00 |
10:02:05.74 |
+07:05:20.7 |
HIP 49100 |
14.20 |
| 2026-05-17 00:00 |
10:02:11.80 |
+07:04:58.4 |
HIP 49100 |
15.69 |
| 2026-05-17 12:00 |
10:02:17.99 |
+07:04:35.4 |
HIP 49100 |
17.22 |
| 2026-05-18 00:00 |
10:02:24.33 |
+07:04:11.5 |
HIP 49100 |
18.80 |
| 2026-05-18 12:00 |
10:02:30.81 |
+07:03:46.8 |
HIP 49100 |
20.42 |
| 2026-05-19 00:00 |
10:02:37.44 |
+07:03:21.3 |
HIP 49316 |
21.68 |
| 2026-05-19 12:00 |
10:02:44.20 |
+07:02:55.0 |
HIP 49316 |
20.27 |
| 2026-05-20 00:00 |
10:02:51.11 |
+07:02:27.9 |
HIP 49316 |
18.88 |
| 2026-05-20 12:00 |
10:02:58.15 |
+07:02:00.0 |
HIP 49316 |
17.54 |
| 2026-05-21 00:00 |
10:03:05.34 |
+07:01:31.3 |
HIP 49316 |
16.27 |
| 2026-05-21 12:00 |
10:03:12.66 |
+07:01:01.7 |
HIP 49316 |
15.10 |
| 2026-05-22 00:00 |
10:03:20.12 |
+07:00:31.4 |
HIP 49316 |
14.07 |
| 2026-05-22 12:00 |
10:03:27.71 |
+07:00:00.3 |
HIP 49316 |
13.24 |
| 2026-05-23 00:00 |
10:03:35.44 |
+06:59:28.3 |
HIP 49316 |
12.64 |
| 2026-05-23 12:00 |
10:03:43.31 |
+06:58:55.6 |
HIP 49316 |
12.35 |
| 2026-05-24 00:00 |
10:03:51.31 |
+06:58:22.1 |
HIP 49316 |
12.39 |
| 2026-05-24 12:00 |
10:03:59.44 |
+06:57:47.8 |
HIP 49316 |
12.78 |
| 2026-05-25 00:00 |
10:04:07.71 |
+06:57:12.7 |
HIP 49316 |
13.50 |
| 2026-05-25 12:00 |
10:04:16.11 |
+06:56:36.8 |
HIP 49316 |
14.53 |
| 2026-05-26 00:00 |
10:04:24.64 |
+06:56:00.2 |
HIP 49316 |
15.81 |
| 2026-05-26 12:00 |
10:04:33.30 |
+06:55:22.8 |
HIP 49316 |
17.31 |
| 2026-05-27 00:00 |
10:04:42.09 |
+06:54:44.6 |
HIP 49316 |
18.99 |
| 2026-05-27 12:00 |
10:04:51.01 |
+06:54:05.6 |
HIP 49316 |
20.80 |
| 2026-05-28 00:00 |
10:05:00.05 |
+06:53:25.8 |
HIP 49316 |
22.74 |
| 2026-05-28 12:00 |
10:05:09.23 |
+06:52:45.3 |
HIP 49519 |
21.97 |
| 2026-05-29 00:00 |
10:05:18.53 |
+06:52:04.0 |
HIP 49519 |
19.73 |
| 2026-05-29 12:00 |
10:05:27.95 |
+06:51:21.9 |
HIP 49519 |
17.52 |
| 2026-05-30 00:00 |
10:05:37.50 |
+06:50:39.1 |
HIP 49519 |
15.34 |
| 2026-05-30 12:00 |
10:05:47.18 |
+06:49:55.5 |
HIP 49519 |
13.25 |
| 2026-05-31 00:00 |
10:05:56.98 |
+06:49:11.2 |
HIP 49519 |
11.31 |
| 2026-05-31 12:00 |
10:06:06.90 |
+06:48:26.1 |
HIP 49519 |
9.63 |
| 2026-06-01 00:00 |
10:06:16.94 |
+06:47:40.3 |
HIP 49519 |
8.40 |
| 2026-06-01 12:00 |
10:06:27.10 |
+06:46:53.7 |
HIP 49519 |
7.88 |
| 2026-06-02 00:00 |
10:06:37.39 |
+06:46:06.3 |
HIP 49519 |
8.24 |