| Parameter |
Value |
| Designation |
C/2016 A1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-11-23T08:54:05.518080Z |
| Orbit solution date (soln_date, UTC) |
2022-07-19T01:12:15Z |
| Obs used |
2143 |
| NEO |
- |
| M1 |
6.400 |
| K1 |
9.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-11-13.0000000 |
| e |
1.00196775 |
| q (au) |
5.327762 |
| a (au) |
-2707.536844 |
| i (deg) |
121.185405 |
| Ω (om, deg) |
128.174457 |
| ω (w, deg) |
10.320070 |
| M (ma, deg) |
-0.000073 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.402 + 3.724\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.402 |
| n |
3.724 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
| 2016-01-01 |
2017-11-22 |
-2.3519 |
+1.891 |
| 2017-11-26 |
2019-03-10 |
-2.2345 |
+1.488 |
| 2019-03-10 |
2020-02-15 |
+16.2456 |
-13.536 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
21:56:21.66 |
+33:43:56.1 |
HIP 108278 |
22.08 |
| 2026-06-01 12:00 |
21:56:19.63 |
+33:44:39.5 |
HIP 108278 |
22.76 |
| 2026-06-02 00:00 |
21:56:17.54 |
+33:45:22.7 |
HIP 108278 |
23.46 |
| 2026-06-02 12:00 |
21:56:15.40 |
+33:46:05.6 |
HIP 108278 |
24.15 |
| 2026-06-03 00:00 |
21:56:13.20 |
+33:46:48.2 |
HIP 108120 |
23.92 |
| 2026-06-03 12:00 |
21:56:10.94 |
+33:47:30.5 |
HIP 108120 |
23.46 |
| 2026-06-04 00:00 |
21:56:08.62 |
+33:48:12.5 |
HIP 108120 |
23.01 |
| 2026-06-04 12:00 |
21:56:06.25 |
+33:48:54.1 |
HIP 108120 |
22.57 |
| 2026-06-05 00:00 |
21:56:03.83 |
+33:49:35.5 |
HIP 108120 |
22.14 |
| 2026-06-05 12:00 |
21:56:01.34 |
+33:50:16.5 |
HIP 108120 |
21.73 |
| 2026-06-06 00:00 |
21:55:58.80 |
+33:50:57.3 |
HIP 108120 |
21.33 |
| 2026-06-06 12:00 |
21:55:56.21 |
+33:51:37.7 |
HIP 108120 |
20.94 |
| 2026-06-07 00:00 |
21:55:53.55 |
+33:52:17.7 |
HIP 108120 |
20.57 |
| 2026-06-07 12:00 |
21:55:50.85 |
+33:52:57.5 |
HIP 108120 |
20.22 |
| 2026-06-08 00:00 |
21:55:48.08 |
+33:53:36.9 |
HIP 108120 |
19.89 |
| 2026-06-08 12:00 |
21:55:45.26 |
+33:54:15.9 |
HIP 108120 |
19.58 |
| 2026-06-09 00:00 |
21:55:42.39 |
+33:54:54.7 |
HIP 108120 |
19.29 |
| 2026-06-09 12:00 |
21:55:39.46 |
+33:55:33.0 |
HIP 108120 |
19.02 |
| 2026-06-10 00:00 |
21:55:36.47 |
+33:56:11.0 |
HIP 108120 |
18.78 |
| 2026-06-10 12:00 |
21:55:33.43 |
+33:56:48.7 |
HIP 108120 |
18.57 |
| 2026-06-11 00:00 |
21:55:30.33 |
+33:57:25.9 |
HIP 108120 |
18.38 |
| 2026-06-11 12:00 |
21:55:27.18 |
+33:58:02.8 |
HIP 108120 |
18.22 |
| 2026-06-12 00:00 |
21:55:23.98 |
+33:58:39.4 |
HIP 108120 |
18.09 |
| 2026-06-12 12:00 |
21:55:20.71 |
+33:59:15.5 |
HIP 108120 |
18.00 |
| 2026-06-13 00:00 |
21:55:17.40 |
+33:59:51.3 |
HIP 108120 |
17.94 |
| 2026-06-13 12:00 |
21:55:14.03 |
+34:00:26.7 |
HIP 108120 |
17.91 |
| 2026-06-14 00:00 |
21:55:10.60 |
+34:01:01.7 |
HIP 108120 |
17.91 |
| 2026-06-14 12:00 |
21:55:07.12 |
+34:01:36.3 |
HIP 108120 |
17.96 |
| 2026-06-15 00:00 |
21:55:03.59 |
+34:02:10.5 |
HIP 108120 |
18.03 |
| 2026-06-15 12:00 |
21:55:00.00 |
+34:02:44.3 |
HIP 108120 |
18.15 |
| 2026-06-16 00:00 |
21:54:56.36 |
+34:03:17.7 |
HIP 108120 |
18.30 |
| 2026-06-16 12:00 |
21:54:52.67 |
+34:03:50.6 |
HIP 108120 |
18.48 |
| 2026-06-17 00:00 |
21:54:48.92 |
+34:04:23.2 |
HIP 108120 |
18.70 |
| 2026-06-17 12:00 |
21:54:45.12 |
+34:04:55.3 |
HIP 108120 |
18.96 |
| 2026-06-18 00:00 |
21:54:41.27 |
+34:05:27.0 |
HIP 108120 |
19.25 |
| 2026-06-18 12:00 |
21:54:37.37 |
+34:05:58.3 |
HIP 108049 |
18.80 |
| 2026-06-19 00:00 |
21:54:33.41 |
+34:06:29.1 |
HIP 108049 |
17.84 |
| 2026-06-19 12:00 |
21:54:29.40 |
+34:06:59.5 |
HIP 108049 |
16.87 |
| 2026-06-20 00:00 |
21:54:25.34 |
+34:07:29.5 |
HIP 108049 |
15.89 |
| 2026-06-20 12:00 |
21:54:21.23 |
+34:07:59.0 |
HIP 108049 |
14.92 |
| 2026-06-21 00:00 |
21:54:17.07 |
+34:08:28.1 |
HIP 108049 |
13.94 |
| 2026-06-21 12:00 |
21:54:12.85 |
+34:08:56.7 |
HIP 108049 |
12.96 |
| 2026-06-22 00:00 |
21:54:08.59 |
+34:09:24.9 |
HIP 108049 |
11.97 |