| Parameter |
Value |
| Designation |
C/2019 A5 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-06-09T10:42:31.567680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:51Z |
| Obs used |
70 |
| NEO |
- |
| M1 |
7.300 |
| K1 |
12.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-01-13T11:48:30.528000Z |
| Discovery magnitude (MPC) |
21.50 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-08-06.0000000 |
| e |
0.70787404 |
| q (au) |
6.324147 |
| a (au) |
21.648700 |
| i (deg) |
67.539002 |
| Ω (om, deg) |
146.619252 |
| ω (w, deg) |
356.039843 |
| M (ma, deg) |
0.563158 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.399 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.399 |
| n |
6.000 |
| gf |
0.988 |
| gb |
-0.862 |
| k |
0.800 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
17:54:40.29 |
+42:23:42.9 |
HIP 87631 |
16.72 |
| 2026-07-29 12:00 |
17:54:33.67 |
+42:22:17.4 |
HIP 87631 |
17.57 |
| 2026-07-30 00:00 |
17:54:27.11 |
+42:20:51.1 |
HIP 87531 |
18.57 |
| 2026-07-30 12:00 |
17:54:20.62 |
+42:19:24.1 |
HIP 87531 |
16.88 |
| 2026-07-31 00:00 |
17:54:14.19 |
+42:17:56.4 |
HIP 87531 |
15.24 |
| 2026-07-31 12:00 |
17:54:07.84 |
+42:16:27.9 |
HIP 87531 |
13.67 |
| 2026-08-01 00:00 |
17:54:01.55 |
+42:14:58.7 |
HIP 87531 |
12.20 |
| 2026-08-01 12:00 |
17:53:55.34 |
+42:13:28.8 |
HIP 87531 |
10.87 |
| 2026-08-02 00:00 |
17:53:49.19 |
+42:11:58.1 |
HIP 87531 |
9.74 |
| 2026-08-02 12:00 |
17:53:43.11 |
+42:10:26.8 |
HIP 87531 |
8.89 |
| 2026-08-03 00:00 |
17:53:37.11 |
+42:08:54.7 |
HIP 87531 |
8.40 |
| 2026-08-03 12:00 |
17:53:31.18 |
+42:07:22.0 |
HIP 87531 |
8.34 |
| 2026-08-04 00:00 |
17:53:25.32 |
+42:05:48.6 |
HIP 87531 |
8.73 |
| 2026-08-04 12:00 |
17:53:19.53 |
+42:04:14.5 |
HIP 87531 |
9.50 |
| 2026-08-05 00:00 |
17:53:13.81 |
+42:02:39.7 |
HIP 87531 |
10.57 |
| 2026-08-05 12:00 |
17:53:08.17 |
+42:01:04.2 |
HIP 87531 |
11.87 |
| 2026-08-06 00:00 |
17:53:02.61 |
+41:59:28.1 |
HIP 87531 |
13.32 |
| 2026-08-06 12:00 |
17:52:57.11 |
+41:57:51.4 |
HIP 87531 |
14.89 |
| 2026-08-07 00:00 |
17:52:51.70 |
+41:56:14.0 |
HIP 87531 |
16.54 |
| 2026-08-07 12:00 |
17:52:46.36 |
+41:54:35.9 |
HIP 87531 |
18.25 |
| 2026-08-08 00:00 |
17:52:41.09 |
+41:52:57.2 |
HIP 87531 |
20.01 |
| 2026-08-08 12:00 |
17:52:35.91 |
+41:51:17.9 |
HIP 87531 |
21.80 |
| 2026-08-09 00:00 |
17:52:30.80 |
+41:49:38.0 |
HIP 87531 |
23.61 |
| 2026-08-09 12:00 |
17:52:25.77 |
+41:47:57.4 |
HIP 87531 |
25.45 |
| 2026-08-10 00:00 |
17:52:20.82 |
+41:46:16.3 |
HIP 87531 |
27.31 |
| 2026-08-10 12:00 |
17:52:15.94 |
+41:44:34.5 |
HIP 87274 |
28.55 |
| 2026-08-11 00:00 |
17:52:11.15 |
+41:42:52.2 |
HIP 87274 |
28.58 |
| 2026-08-11 12:00 |
17:52:06.44 |
+41:41:09.3 |
HIP 87274 |
28.76 |
| 2026-08-12 00:00 |
17:52:01.80 |
+41:39:25.8 |
HIP 87274 |
29.08 |
| 2026-08-12 12:00 |
17:51:57.25 |
+41:37:41.7 |
HIP 87274 |
29.54 |
| 2026-08-13 00:00 |
17:51:52.78 |
+41:35:57.1 |
HIP 87313 |
28.85 |
| 2026-08-13 12:00 |
17:51:48.39 |
+41:34:12.0 |
HIP 87313 |
26.93 |
| 2026-08-14 00:00 |
17:51:44.08 |
+41:32:26.3 |
HIP 87313 |
25.03 |
| 2026-08-14 12:00 |
17:51:39.86 |
+41:30:40.0 |
HIP 87313 |
23.13 |
| 2026-08-15 00:00 |
17:51:35.72 |
+41:28:53.3 |
HIP 87313 |
21.24 |
| 2026-08-15 12:00 |
17:51:31.66 |
+41:27:06.0 |
HIP 87313 |
19.37 |
| 2026-08-16 00:00 |
17:51:27.69 |
+41:25:18.2 |
HIP 87313 |
17.51 |
| 2026-08-16 12:00 |
17:51:23.80 |
+41:23:30.0 |
HIP 87313 |
15.67 |
| 2026-08-17 00:00 |
17:51:19.99 |
+41:21:41.2 |
HIP 87313 |
13.88 |
| 2026-08-17 12:00 |
17:51:16.27 |
+41:19:52.0 |
HIP 87313 |
12.13 |
| 2026-08-18 00:00 |
17:51:12.63 |
+41:18:02.3 |
HIP 87313 |
10.47 |
| 2026-08-18 12:00 |
17:51:09.08 |
+41:16:12.1 |
HIP 87313 |
8.94 |
| 2026-08-19 00:00 |
17:51:05.62 |
+41:14:21.5 |
HIP 87313 |
7.61 |