| Parameter |
Value |
| Designation |
C/2015 T5 (Sheppard-Tholen) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-01-24T12:14:36.277440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:15Z |
| Obs used |
22 |
| NEO |
- |
| M1 |
7.700 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-12-20.0000000 |
| e |
0.66608261 |
| q (au) |
9.338302 |
| a (au) |
27.965906 |
| i (deg) |
11.048354 |
| Ω (om, deg) |
311.192699 |
| ω (w, deg) |
61.838999 |
| M (ma, deg) |
359.763346 |
Magnitude
Scatter + Global Linear
$$
M_a = (1.877 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
1.877 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
9.997 |
| 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 |
07:53:40.52 |
+23:48:47.1 |
HIP 38603 |
20.10 |
| 2026-07-29 12:00 |
07:53:48.33 |
+23:48:23.5 |
HIP 38603 |
19.10 |
| 2026-07-30 00:00 |
07:53:56.13 |
+23:47:59.9 |
HIP 38603 |
18.24 |
| 2026-07-30 12:00 |
07:54:03.92 |
+23:47:36.3 |
HIP 38603 |
17.53 |
| 2026-07-31 00:00 |
07:54:11.71 |
+23:47:12.8 |
HIP 38603 |
16.99 |
| 2026-07-31 12:00 |
07:54:19.48 |
+23:46:49.3 |
HIP 38603 |
16.63 |
| 2026-08-01 00:00 |
07:54:27.24 |
+23:46:25.9 |
HIP 38603 |
16.47 |
| 2026-08-01 12:00 |
07:54:34.98 |
+23:46:02.5 |
HIP 38603 |
16.50 |
| 2026-08-02 00:00 |
07:54:42.72 |
+23:45:39.2 |
HIP 38603 |
16.74 |
| 2026-08-02 12:00 |
07:54:50.44 |
+23:45:15.9 |
HIP 38755 |
16.97 |
| 2026-08-03 00:00 |
07:54:58.15 |
+23:44:52.6 |
HIP 38755 |
15.16 |
| 2026-08-03 12:00 |
07:55:05.85 |
+23:44:29.4 |
HIP 38755 |
13.36 |
| 2026-08-04 00:00 |
07:55:13.54 |
+23:44:06.3 |
HIP 38755 |
11.56 |
| 2026-08-04 12:00 |
07:55:21.21 |
+23:43:43.2 |
HIP 38755 |
9.76 |
| 2026-08-05 00:00 |
07:55:28.87 |
+23:43:20.1 |
HIP 38755 |
7.97 |
| 2026-08-05 12:00 |
07:55:36.51 |
+23:42:57.1 |
HIP 38755 |
6.17 |
| 2026-08-06 00:00 |
07:55:44.14 |
+23:42:34.2 |
HIP 38755 |
4.39 |
| 2026-08-06 12:00 |
07:55:51.75 |
+23:42:11.3 |
HIP 38755 |
2.60 |
| 2026-08-07 00:00 |
07:55:59.35 |
+23:41:48.4 |
HIP 38755 |
0.82 |
| 2026-08-07 12:00 |
07:56:06.93 |
+23:41:25.6 |
HIP 38755 |
0.96 |
| 2026-08-08 00:00 |
07:56:14.49 |
+23:41:02.9 |
HIP 38755 |
2.73 |
| 2026-08-08 12:00 |
07:56:22.04 |
+23:40:40.2 |
HIP 38755 |
4.50 |
| 2026-08-09 00:00 |
07:56:29.57 |
+23:40:17.6 |
HIP 38761 |
6.02 |
| 2026-08-09 12:00 |
07:56:37.08 |
+23:39:55.0 |
HIP 38761 |
7.44 |
| 2026-08-10 00:00 |
07:56:44.58 |
+23:39:32.5 |
HIP 38761 |
8.98 |
| 2026-08-10 12:00 |
07:56:52.06 |
+23:39:10.1 |
HIP 38761 |
10.58 |
| 2026-08-11 00:00 |
07:56:59.52 |
+23:38:47.7 |
HIP 38761 |
12.23 |
| 2026-08-11 12:00 |
07:57:06.96 |
+23:38:25.4 |
HIP 38761 |
13.89 |
| 2026-08-12 00:00 |
07:57:14.38 |
+23:38:03.2 |
HIP 38761 |
15.57 |
| 2026-08-12 12:00 |
07:57:21.78 |
+23:37:41.0 |
HIP 38761 |
17.25 |
| 2026-08-13 00:00 |
07:57:29.16 |
+23:37:18.9 |
HIP 38761 |
18.94 |
| 2026-08-13 12:00 |
07:57:36.52 |
+23:36:56.8 |
HIP 38761 |
20.63 |
| 2026-08-14 00:00 |
07:57:43.85 |
+23:36:34.9 |
HIP 38761 |
22.32 |
| 2026-08-14 12:00 |
07:57:51.17 |
+23:36:13.0 |
HIP 38761 |
24.01 |
| 2026-08-15 00:00 |
07:57:58.47 |
+23:35:51.2 |
HIP 38761 |
25.70 |
| 2026-08-15 12:00 |
07:58:05.74 |
+23:35:29.4 |
HIP 38761 |
27.39 |
| 2026-08-16 00:00 |
07:58:12.99 |
+23:35:07.7 |
HIP 38761 |
29.07 |
| 2026-08-16 12:00 |
07:58:20.22 |
+23:34:46.1 |
HIP 39077 |
30.39 |
| 2026-08-17 00:00 |
07:58:27.42 |
+23:34:24.6 |
HIP 39077 |
29.10 |
| 2026-08-17 12:00 |
07:58:34.60 |
+23:34:03.2 |
HIP 39077 |
27.86 |
| 2026-08-18 00:00 |
07:58:41.75 |
+23:33:41.8 |
HIP 39077 |
26.67 |
| 2026-08-18 12:00 |
07:58:48.89 |
+23:33:20.5 |
HIP 39077 |
25.54 |
| 2026-08-19 00:00 |
07:58:55.99 |
+23:32:59.3 |
HIP 39077 |
24.47 |