| 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) |
| 2026-05-12 00:00 |
16:30:41.98 |
+19:27:47.5 |
HIP 80905 |
13.62 |
| 2026-05-12 12:00 |
16:30:37.61 |
+19:28:07.8 |
HIP 80905 |
14.54 |
| 2026-05-13 00:00 |
16:30:33.23 |
+19:28:27.8 |
HIP 80905 |
15.48 |
| 2026-05-13 12:00 |
16:30:28.84 |
+19:28:47.4 |
HIP 80769 |
14.68 |
| 2026-05-14 00:00 |
16:30:24.44 |
+19:29:06.6 |
HIP 80769 |
13.61 |
| 2026-05-14 12:00 |
16:30:20.02 |
+19:29:25.4 |
HIP 80769 |
12.55 |
| 2026-05-15 00:00 |
16:30:15.59 |
+19:29:43.8 |
HIP 80769 |
11.48 |
| 2026-05-15 12:00 |
16:30:11.15 |
+19:30:01.9 |
HIP 80769 |
10.42 |
| 2026-05-16 00:00 |
16:30:06.70 |
+19:30:19.5 |
HIP 80769 |
9.36 |
| 2026-05-16 12:00 |
16:30:02.23 |
+19:30:36.8 |
HIP 80769 |
8.30 |
| 2026-05-17 00:00 |
16:29:57.76 |
+19:30:53.7 |
HIP 80769 |
7.25 |
| 2026-05-17 12:00 |
16:29:53.28 |
+19:31:10.2 |
HIP 80769 |
6.22 |
| 2026-05-18 00:00 |
16:29:48.79 |
+19:31:26.2 |
HIP 80769 |
5.20 |
| 2026-05-18 12:00 |
16:29:44.29 |
+19:31:41.9 |
HIP 80769 |
4.22 |
| 2026-05-19 00:00 |
16:29:39.78 |
+19:31:57.2 |
HIP 80769 |
3.31 |
| 2026-05-19 12:00 |
16:29:35.26 |
+19:32:12.1 |
HIP 80769 |
2.54 |
| 2026-05-20 00:00 |
16:29:30.74 |
+19:32:26.6 |
HIP 80769 |
2.06 |
| 2026-05-20 12:00 |
16:29:26.20 |
+19:32:40.7 |
HIP 80769 |
2.11 |
| 2026-05-21 00:00 |
16:29:21.66 |
+19:32:54.4 |
HIP 80769 |
2.65 |
| 2026-05-21 12:00 |
16:29:17.12 |
+19:33:07.7 |
HIP 80769 |
3.46 |
| 2026-05-22 00:00 |
16:29:12.57 |
+19:33:20.6 |
HIP 80769 |
4.39 |
| 2026-05-22 12:00 |
16:29:08.01 |
+19:33:33.1 |
HIP 80769 |
5.37 |
| 2026-05-23 00:00 |
16:29:03.45 |
+19:33:45.2 |
HIP 80769 |
6.40 |
| 2026-05-23 12:00 |
16:28:58.88 |
+19:33:56.9 |
HIP 80769 |
7.43 |
| 2026-05-24 00:00 |
16:28:54.31 |
+19:34:08.1 |
HIP 80769 |
8.49 |
| 2026-05-24 12:00 |
16:28:49.74 |
+19:34:19.0 |
HIP 80769 |
9.54 |
| 2026-05-25 00:00 |
16:28:45.16 |
+19:34:29.4 |
HIP 80769 |
10.61 |
| 2026-05-25 12:00 |
16:28:40.58 |
+19:34:39.5 |
HIP 80769 |
11.68 |
| 2026-05-26 00:00 |
16:28:36.00 |
+19:34:49.1 |
HIP 80769 |
12.75 |
| 2026-05-26 12:00 |
16:28:31.41 |
+19:34:58.4 |
HIP 80769 |
13.82 |
| 2026-05-27 00:00 |
16:28:26.82 |
+19:35:07.2 |
HIP 80769 |
14.89 |
| 2026-05-27 12:00 |
16:28:22.23 |
+19:35:15.6 |
HIP 80769 |
15.96 |
| 2026-05-28 00:00 |
16:28:17.64 |
+19:35:23.6 |
HIP 80769 |
17.04 |
| 2026-05-28 12:00 |
16:28:13.05 |
+19:35:31.2 |
HIP 80769 |
18.11 |
| 2026-05-29 00:00 |
16:28:08.46 |
+19:35:38.4 |
HIP 80769 |
19.19 |
| 2026-05-29 12:00 |
16:28:03.87 |
+19:35:45.2 |
HIP 80573 |
19.61 |
| 2026-05-30 00:00 |
16:27:59.28 |
+19:35:51.5 |
HIP 80573 |
18.92 |
| 2026-05-30 12:00 |
16:27:54.68 |
+19:35:57.5 |
HIP 80573 |
18.27 |
| 2026-05-31 00:00 |
16:27:50.10 |
+19:36:03.0 |
HIP 80573 |
17.66 |
| 2026-05-31 12:00 |
16:27:45.51 |
+19:36:08.1 |
HIP 80573 |
17.09 |
| 2026-06-01 00:00 |
16:27:40.92 |
+19:36:12.8 |
HIP 80573 |
16.56 |
| 2026-06-01 12:00 |
16:27:36.34 |
+19:36:17.1 |
HIP 80573 |
16.09 |
| 2026-06-02 00:00 |
16:27:31.76 |
+19:36:21.0 |
HIP 80573 |
15.67 |