| 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) |
| 2026-09-20 00:00 |
08:05:24.29 |
+23:13:57.4 |
HIP 39465 |
22.20 |
| 2026-09-20 12:00 |
08:05:29.08 |
+23:13:43.6 |
HIP 39465 |
23.28 |
| 2026-09-21 00:00 |
08:05:33.83 |
+23:13:30.0 |
HIP 39465 |
24.35 |
| 2026-09-21 12:00 |
08:05:38.53 |
+23:13:16.5 |
HIP 39465 |
25.42 |
| 2026-09-22 00:00 |
08:05:43.19 |
+23:13:03.2 |
HIP 39465 |
26.48 |
| 2026-09-22 12:00 |
08:05:47.80 |
+23:12:50.0 |
HIP 39546 |
27.16 |
| 2026-09-23 00:00 |
08:05:52.36 |
+23:12:37.0 |
HIP 39546 |
27.86 |
| 2026-09-23 12:00 |
08:05:56.87 |
+23:12:24.1 |
HIP 39546 |
28.57 |
| 2026-09-24 00:00 |
08:06:01.34 |
+23:12:11.4 |
HIP 39705 |
28.61 |
| 2026-09-24 12:00 |
08:06:05.76 |
+23:11:58.8 |
HIP 39705 |
27.98 |
| 2026-09-25 00:00 |
08:06:10.13 |
+23:11:46.4 |
HIP 39705 |
27.39 |
| 2026-09-25 12:00 |
08:06:14.45 |
+23:11:34.1 |
HIP 39705 |
26.83 |
| 2026-09-26 00:00 |
08:06:18.73 |
+23:11:22.0 |
HIP 39705 |
26.30 |
| 2026-09-26 12:00 |
08:06:22.96 |
+23:11:10.0 |
HIP 39705 |
25.80 |
| 2026-09-27 00:00 |
08:06:27.13 |
+23:10:58.2 |
HIP 39705 |
25.35 |
| 2026-09-27 12:00 |
08:06:31.26 |
+23:10:46.5 |
HIP 39705 |
24.92 |
| 2026-09-28 00:00 |
08:06:35.34 |
+23:10:35.0 |
HIP 39705 |
24.53 |
| 2026-09-28 12:00 |
08:06:39.38 |
+23:10:23.7 |
HIP 39705 |
24.18 |
| 2026-09-29 00:00 |
08:06:43.36 |
+23:10:12.5 |
HIP 39705 |
23.87 |
| 2026-09-29 12:00 |
08:06:47.29 |
+23:10:01.4 |
HIP 39705 |
23.59 |
| 2026-09-30 00:00 |
08:06:51.17 |
+23:09:50.6 |
HIP 39705 |
23.35 |
| 2026-09-30 12:00 |
08:06:55.00 |
+23:09:39.8 |
HIP 39705 |
23.14 |
| 2026-10-01 00:00 |
08:06:58.78 |
+23:09:29.3 |
HIP 39705 |
22.97 |
| 2026-10-01 12:00 |
08:07:02.51 |
+23:09:18.9 |
HIP 39705 |
22.83 |
| 2026-10-02 00:00 |
08:07:06.19 |
+23:09:08.6 |
HIP 39705 |
22.73 |
| 2026-10-02 12:00 |
08:07:09.81 |
+23:08:58.5 |
HIP 39705 |
22.66 |
| 2026-10-03 00:00 |
08:07:13.39 |
+23:08:48.6 |
HIP 39705 |
22.63 |
| 2026-10-03 12:00 |
08:07:16.91 |
+23:08:38.9 |
HIP 39705 |
22.63 |
| 2026-10-04 00:00 |
08:07:20.38 |
+23:08:29.3 |
HIP 39788 |
22.63 |
| 2026-10-04 12:00 |
08:07:23.80 |
+23:08:19.8 |
HIP 39788 |
22.25 |
| 2026-10-05 00:00 |
08:07:27.17 |
+23:08:10.6 |
HIP 39788 |
21.90 |
| 2026-10-05 12:00 |
08:07:30.48 |
+23:08:01.5 |
HIP 39788 |
21.57 |
| 2026-10-06 00:00 |
08:07:33.74 |
+23:07:52.5 |
HIP 39788 |
21.28 |
| 2026-10-06 12:00 |
08:07:36.94 |
+23:07:43.8 |
HIP 39788 |
21.01 |
| 2026-10-07 00:00 |
08:07:40.10 |
+23:07:35.2 |
HIP 39788 |
20.77 |
| 2026-10-07 12:00 |
08:07:43.19 |
+23:07:26.7 |
HIP 39788 |
20.56 |
| 2026-10-08 00:00 |
08:07:46.24 |
+23:07:18.5 |
HIP 39788 |
20.37 |
| 2026-10-08 12:00 |
08:07:49.23 |
+23:07:10.4 |
HIP 39788 |
20.22 |
| 2026-10-09 00:00 |
08:07:52.16 |
+23:07:02.5 |
HIP 39788 |
20.08 |
| 2026-10-09 12:00 |
08:07:55.04 |
+23:06:54.7 |
HIP 39788 |
19.98 |
| 2026-10-10 00:00 |
08:07:57.87 |
+23:06:47.1 |
HIP 39788 |
19.89 |
| 2026-10-10 12:00 |
08:08:00.64 |
+23:06:39.7 |
HIP 39788 |
19.83 |
| 2026-10-11 00:00 |
08:08:03.35 |
+23:06:32.5 |
HIP 39788 |
19.79 |