| Parameter |
Value |
| Designation |
C/2015 T4 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-06-18T22:43:23.779200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:15Z |
| Obs used |
345 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
16.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-12-16.0000000 |
| e |
0.97361730 |
| q (au) |
2.296377 |
| a (au) |
87.040989 |
| i (deg) |
87.917192 |
| Ω (om, deg) |
251.787616 |
| ω (w, deg) |
270.135756 |
| M (ma, deg) |
359.774313 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.288 + 5.229\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.288 |
| n |
5.229 |
| gf |
0.992 |
| gb |
-1.000 |
| k |
0.999 |
| δ90 |
9.995 |
| 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) |
| 2026-06-01 00:00 |
17:21:38.00 |
+35:00:10.2 |
HIP 85014 |
25.51 |
| 2026-06-01 12:00 |
17:21:31.90 |
+35:00:32.2 |
HIP 84847 |
25.35 |
| 2026-06-02 00:00 |
17:21:25.80 |
+35:00:53.6 |
HIP 84847 |
24.42 |
| 2026-06-02 12:00 |
17:21:19.69 |
+35:01:14.4 |
HIP 84847 |
23.53 |
| 2026-06-03 00:00 |
17:21:13.56 |
+35:01:34.7 |
HIP 84847 |
22.69 |
| 2026-06-03 12:00 |
17:21:07.43 |
+35:01:54.4 |
HIP 84847 |
21.90 |
| 2026-06-04 00:00 |
17:21:01.29 |
+35:02:13.5 |
HIP 84847 |
21.16 |
| 2026-06-04 12:00 |
17:20:55.15 |
+35:02:32.1 |
HIP 84847 |
20.49 |
| 2026-06-05 00:00 |
17:20:49.00 |
+35:02:50.1 |
HIP 84847 |
19.90 |
| 2026-06-05 12:00 |
17:20:42.84 |
+35:03:07.5 |
HIP 84847 |
19.38 |
| 2026-06-06 00:00 |
17:20:36.67 |
+35:03:24.3 |
HIP 84847 |
18.94 |
| 2026-06-06 12:00 |
17:20:30.50 |
+35:03:40.6 |
HIP 84847 |
18.59 |
| 2026-06-07 00:00 |
17:20:24.33 |
+35:03:56.3 |
HIP 84847 |
18.34 |
| 2026-06-07 12:00 |
17:20:18.15 |
+35:04:11.4 |
HIP 84847 |
18.18 |
| 2026-06-08 00:00 |
17:20:11.97 |
+35:04:25.9 |
HIP 84847 |
18.12 |
| 2026-06-08 12:00 |
17:20:05.78 |
+35:04:39.9 |
HIP 84847 |
18.17 |
| 2026-06-09 00:00 |
17:19:59.59 |
+35:04:53.3 |
HIP 84847 |
18.31 |
| 2026-06-09 12:00 |
17:19:53.40 |
+35:05:06.1 |
HIP 84847 |
18.55 |
| 2026-06-10 00:00 |
17:19:47.21 |
+35:05:18.3 |
HIP 84847 |
18.88 |
| 2026-06-10 12:00 |
17:19:41.01 |
+35:05:29.9 |
HIP 84847 |
19.31 |
| 2026-06-11 00:00 |
17:19:34.82 |
+35:05:41.0 |
HIP 84847 |
19.81 |
| 2026-06-11 12:00 |
17:19:28.62 |
+35:05:51.5 |
HIP 84847 |
20.39 |
| 2026-06-12 00:00 |
17:19:22.43 |
+35:06:01.4 |
HIP 84847 |
21.04 |
| 2026-06-12 12:00 |
17:19:16.24 |
+35:06:10.7 |
HIP 84847 |
21.75 |
| 2026-06-13 00:00 |
17:19:10.04 |
+35:06:19.4 |
HIP 84847 |
22.51 |
| 2026-06-13 12:00 |
17:19:03.85 |
+35:06:27.6 |
HIP 84679 |
22.55 |
| 2026-06-14 00:00 |
17:18:57.67 |
+35:06:35.1 |
HIP 84679 |
22.45 |
| 2026-06-14 12:00 |
17:18:51.48 |
+35:06:42.1 |
HIP 84679 |
22.40 |
| 2026-06-15 00:00 |
17:18:45.30 |
+35:06:48.5 |
HIP 84679 |
22.42 |
| 2026-06-15 12:00 |
17:18:39.12 |
+35:06:54.3 |
HIP 84679 |
22.51 |
| 2026-06-16 00:00 |
17:18:32.95 |
+35:06:59.5 |
HIP 84679 |
22.65 |
| 2026-06-16 12:00 |
17:18:26.78 |
+35:07:04.2 |
HIP 84679 |
22.85 |
| 2026-06-17 00:00 |
17:18:20.62 |
+35:07:08.3 |
HIP 84679 |
23.11 |
| 2026-06-17 12:00 |
17:18:14.47 |
+35:07:11.8 |
HIP 84679 |
23.43 |
| 2026-06-18 00:00 |
17:18:08.32 |
+35:07:14.7 |
HIP 84679 |
23.80 |
| 2026-06-18 12:00 |
17:18:02.18 |
+35:07:17.0 |
HIP 84679 |
24.22 |
| 2026-06-19 00:00 |
17:17:56.05 |
+35:07:18.7 |
HIP 84679 |
24.69 |
| 2026-06-19 12:00 |
17:17:49.92 |
+35:07:19.9 |
HIP 84679 |
25.20 |
| 2026-06-20 00:00 |
17:17:43.81 |
+35:07:20.5 |
HIP 84679 |
25.75 |
| 2026-06-20 12:00 |
17:17:37.70 |
+35:07:20.5 |
HIP 84679 |
26.34 |
| 2026-06-21 00:00 |
17:17:31.61 |
+35:07:20.0 |
HIP 84679 |
26.97 |
| 2026-06-21 12:00 |
17:17:25.53 |
+35:07:18.9 |
HIP 84679 |
27.63 |
| 2026-06-22 00:00 |
17:17:19.45 |
+35:07:17.2 |
HIP 84679 |
28.33 |