| Parameter |
Value |
| Designation |
C/2016 T3 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-09-06T23:30:05.921280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:27Z |
| Obs used |
436 |
| NEO |
- |
| M1 |
13.700 |
| K1 |
4.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-06-25.0000000 |
| e |
0.98138749 |
| q (au) |
2.649481 |
| a (au) |
142.349476 |
| i (deg) |
22.675960 |
| Ω (om, deg) |
271.748362 |
| ω (w, deg) |
194.677924 |
| M (ma, deg) |
359.957068 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.344 + 2.067\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.344 |
| n |
2.067 |
| gf |
1.000 |
| gb |
-0.500 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2016-10-10 |
2017-09-06 |
+7.4124 |
-4.382 |
| 2017-09-17 |
2018-04-18 |
+5.6541 |
-2.485 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
16:21:23.94 |
-31:37:53.8 |
HIP 80108 |
8.58 |
| 2026-05-12 12:00 |
16:21:18.17 |
-31:37:42.4 |
HIP 80108 |
8.35 |
| 2026-05-13 00:00 |
16:21:12.38 |
-31:37:30.8 |
HIP 80108 |
8.30 |
| 2026-05-13 12:00 |
16:21:06.58 |
-31:37:19.1 |
HIP 80108 |
8.44 |
| 2026-05-14 00:00 |
16:21:00.76 |
-31:37:07.1 |
HIP 80108 |
8.77 |
| 2026-05-14 12:00 |
16:20:54.93 |
-31:36:55.0 |
HIP 80108 |
9.25 |
| 2026-05-15 00:00 |
16:20:49.08 |
-31:36:42.7 |
HIP 80108 |
9.88 |
| 2026-05-15 12:00 |
16:20:43.23 |
-31:36:30.2 |
HIP 80108 |
10.62 |
| 2026-05-16 00:00 |
16:20:37.36 |
-31:36:17.6 |
HIP 80108 |
11.46 |
| 2026-05-16 12:00 |
16:20:31.47 |
-31:36:04.8 |
HIP 80108 |
12.38 |
| 2026-05-17 00:00 |
16:20:25.58 |
-31:35:51.8 |
HIP 80108 |
13.36 |
| 2026-05-17 12:00 |
16:20:19.68 |
-31:35:38.6 |
HIP 80108 |
14.38 |
| 2026-05-18 00:00 |
16:20:13.76 |
-31:35:25.3 |
HIP 80108 |
15.45 |
| 2026-05-18 12:00 |
16:20:07.84 |
-31:35:11.8 |
HIP 80108 |
16.55 |
| 2026-05-19 00:00 |
16:20:01.91 |
-31:34:58.2 |
HIP 80108 |
17.68 |
| 2026-05-19 12:00 |
16:19:55.97 |
-31:34:44.4 |
HIP 80108 |
18.83 |
| 2026-05-20 00:00 |
16:19:50.02 |
-31:34:30.4 |
HIP 80108 |
20.00 |
| 2026-05-20 12:00 |
16:19:44.06 |
-31:34:16.2 |
HIP 79873 |
19.46 |
| 2026-05-21 00:00 |
16:19:38.10 |
-31:34:01.9 |
HIP 79873 |
18.23 |
| 2026-05-21 12:00 |
16:19:32.14 |
-31:33:47.5 |
HIP 79873 |
17.02 |
| 2026-05-22 00:00 |
16:19:26.16 |
-31:33:32.8 |
HIP 79873 |
15.81 |
| 2026-05-22 12:00 |
16:19:20.19 |
-31:33:18.0 |
HIP 79873 |
14.62 |
| 2026-05-23 00:00 |
16:19:14.21 |
-31:33:03.1 |
HIP 79873 |
13.46 |
| 2026-05-23 12:00 |
16:19:08.22 |
-31:32:48.0 |
HIP 79873 |
12.31 |
| 2026-05-24 00:00 |
16:19:02.24 |
-31:32:32.7 |
HIP 79873 |
11.21 |
| 2026-05-24 12:00 |
16:18:56.25 |
-31:32:17.3 |
HIP 79873 |
10.14 |
| 2026-05-25 00:00 |
16:18:50.26 |
-31:32:01.8 |
HIP 79873 |
9.14 |
| 2026-05-25 12:00 |
16:18:44.26 |
-31:31:46.1 |
HIP 79873 |
8.23 |
| 2026-05-26 00:00 |
16:18:38.27 |
-31:31:30.2 |
HIP 79873 |
7.44 |
| 2026-05-26 12:00 |
16:18:32.28 |
-31:31:14.2 |
HIP 79873 |
6.81 |
| 2026-05-27 00:00 |
16:18:26.28 |
-31:30:58.0 |
HIP 79873 |
6.38 |
| 2026-05-27 12:00 |
16:18:20.29 |
-31:30:41.7 |
HIP 79873 |
6.21 |
| 2026-05-28 00:00 |
16:18:14.30 |
-31:30:25.2 |
HIP 79873 |
6.32 |
| 2026-05-28 12:00 |
16:18:08.31 |
-31:30:08.7 |
HIP 79873 |
6.68 |
| 2026-05-29 00:00 |
16:18:02.33 |
-31:29:51.9 |
HIP 79873 |
7.26 |
| 2026-05-29 12:00 |
16:17:56.34 |
-31:29:35.0 |
HIP 79873 |
8.02 |
| 2026-05-30 00:00 |
16:17:50.36 |
-31:29:18.0 |
HIP 79873 |
8.91 |
| 2026-05-30 12:00 |
16:17:44.39 |
-31:29:00.8 |
HIP 79873 |
9.89 |
| 2026-05-31 00:00 |
16:17:38.41 |
-31:28:43.6 |
HIP 79873 |
10.95 |
| 2026-05-31 12:00 |
16:17:32.45 |
-31:28:26.1 |
HIP 79873 |
12.05 |
| 2026-06-01 00:00 |
16:17:26.49 |
-31:28:08.5 |
HIP 79873 |
13.19 |
| 2026-06-01 12:00 |
16:17:20.53 |
-31:27:50.8 |
HIP 79873 |
14.35 |
| 2026-06-02 00:00 |
16:17:14.58 |
-31:27:33.0 |
HIP 79873 |
15.54 |