C/2016 A5 (PANSTARRS)
| Parameter |
Value |
| Designation |
C/2016 A5 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-06-28T07:50:25.661760Z |
| Orbit solution date (soln_date, UTC) |
2022-07-06T03:12:22Z |
| Obs used |
46 |
| NEO |
- |
| M1 |
13.100 |
| K1 |
11.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-12-22.0000000 |
| e |
0.99730397 |
| q (au) |
2.947450 |
| a (au) |
1093.256056 |
| i (deg) |
40.327049 |
| Ω (om, deg) |
136.218315 |
| ω (w, deg) |
321.625267 |
| M (ma, deg) |
0.004817 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.549 + 4.558\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.549 |
| n |
4.558 |
| gf |
0.973 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
16:34:45.56 |
+17:21:11.1 |
HIP 81230 |
17.97 |
| 2026-02-03 12:00 |
16:34:48.25 |
+17:21:46.4 |
HIP 81230 |
18.14 |
| 2026-02-04 00:00 |
16:34:50.89 |
+17:22:21.9 |
HIP 81230 |
18.36 |
| 2026-02-04 12:00 |
16:34:53.50 |
+17:22:57.7 |
HIP 81285 |
18.52 |
| 2026-02-05 00:00 |
16:34:56.07 |
+17:23:33.7 |
HIP 81285 |
17.76 |
| 2026-02-05 12:00 |
16:34:58.60 |
+17:24:09.9 |
HIP 81285 |
17.02 |
| 2026-02-06 00:00 |
16:35:01.09 |
+17:24:46.4 |
HIP 81285 |
16.30 |
| 2026-02-06 12:00 |
16:35:03.54 |
+17:25:23.1 |
HIP 81285 |
15.61 |
| 2026-02-07 00:00 |
16:35:05.95 |
+17:26:00.1 |
HIP 81285 |
14.94 |
| 2026-02-07 12:00 |
16:35:08.32 |
+17:26:37.3 |
HIP 81285 |
14.29 |
| 2026-02-08 00:00 |
16:35:10.66 |
+17:27:14.7 |
HIP 81285 |
13.67 |
| 2026-02-08 12:00 |
16:35:12.95 |
+17:27:52.4 |
HIP 81285 |
13.09 |
| 2026-02-09 00:00 |
16:35:15.21 |
+17:28:30.2 |
HIP 81285 |
12.55 |
| 2026-02-09 12:00 |
16:35:17.42 |
+17:29:08.3 |
HIP 81285 |
12.05 |
| 2026-02-10 00:00 |
16:35:19.59 |
+17:29:46.6 |
HIP 81285 |
11.60 |
| 2026-02-10 12:00 |
16:35:21.72 |
+17:30:25.2 |
HIP 81285 |
11.19 |
| 2026-02-11 00:00 |
16:35:23.82 |
+17:31:03.9 |
HIP 81285 |
10.85 |
| 2026-02-11 12:00 |
16:35:25.87 |
+17:31:42.9 |
HIP 81285 |
10.57 |
| 2026-02-12 00:00 |
16:35:27.88 |
+17:32:22.0 |
HIP 81285 |
10.35 |
| 2026-02-12 12:00 |
16:35:29.85 |
+17:33:01.4 |
HIP 81285 |
10.21 |
| 2026-02-13 00:00 |
16:35:31.77 |
+17:33:41.0 |
HIP 81285 |
10.14 |
| 2026-02-13 12:00 |
16:35:33.66 |
+17:34:20.7 |
HIP 81285 |
10.14 |
| 2026-02-14 00:00 |
16:35:35.51 |
+17:35:00.7 |
HIP 81285 |
10.21 |
| 2026-02-14 12:00 |
16:35:37.31 |
+17:35:40.9 |
HIP 81285 |
10.36 |
| 2026-02-15 00:00 |
16:35:39.07 |
+17:36:21.2 |
HIP 81285 |
10.57 |
| 2026-02-15 12:00 |
16:35:40.79 |
+17:37:01.7 |
HIP 81285 |
10.85 |
| 2026-02-16 00:00 |
16:35:42.47 |
+17:37:42.4 |
HIP 81285 |
11.18 |
| 2026-02-16 12:00 |
16:35:44.10 |
+17:38:23.3 |
HIP 81285 |
11.56 |
| 2026-02-17 00:00 |
16:35:45.69 |
+17:39:04.4 |
HIP 81285 |
11.99 |
| 2026-02-17 12:00 |
16:35:47.24 |
+17:39:45.6 |
HIP 81285 |
12.46 |
| 2026-02-18 00:00 |
16:35:48.75 |
+17:40:27.0 |
HIP 81285 |
12.97 |
| 2026-02-18 12:00 |
16:35:50.22 |
+17:41:08.6 |
HIP 81285 |
13.51 |
| 2026-02-19 00:00 |
16:35:51.64 |
+17:41:50.3 |
HIP 81285 |
14.07 |
| 2026-02-19 12:00 |
16:35:53.02 |
+17:42:32.2 |
HIP 81285 |
14.66 |
| 2026-02-20 00:00 |
16:35:54.35 |
+17:43:14.3 |
HIP 81285 |
15.27 |
| 2026-02-20 12:00 |
16:35:55.65 |
+17:43:56.5 |
HIP 81285 |
15.90 |
| 2026-02-21 00:00 |
16:35:56.90 |
+17:44:38.8 |
HIP 81285 |
16.55 |
| 2026-02-21 12:00 |
16:35:58.10 |
+17:45:21.3 |
HIP 81285 |
17.21 |
| 2026-02-22 00:00 |
16:35:59.26 |
+17:46:03.9 |
HIP 81285 |
17.88 |
| 2026-02-22 12:00 |
16:36:00.38 |
+17:46:46.7 |
HIP 81285 |
18.56 |
| 2026-02-23 00:00 |
16:36:01.46 |
+17:47:29.6 |
HIP 81285 |
19.25 |
| 2026-02-23 12:00 |
16:36:02.49 |
+17:48:12.6 |
HIP 81285 |
19.95 |
| 2026-02-24 00:00 |
16:36:03.48 |
+17:48:55.7 |
HIP 81285 |
20.65 |