| Parameter |
Value |
| Designation |
C/2019 Y5 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-08-18T04:08:32.138880Z |
| Orbit solution date (soln_date, UTC) |
2023-01-14T00:12:31Z |
| Obs used |
70 |
| NEO |
- |
| M1 |
13.000 |
| K1 |
7.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-12-28T05:41:07.382400Z |
| Discovery magnitude (MPC) |
21.47 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-07-16.0000000 |
| e |
0.99391885 |
| q (au) |
4.914443 |
| a (au) |
808.144135 |
| i (deg) |
82.832615 |
| Ω (om, deg) |
51.777609 |
| ω (w, deg) |
303.500296 |
| M (ma, deg) |
0.014279 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.916 + 4.210\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.916 |
| n |
4.210 |
| gf |
0.998 |
| gb |
-0.918 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
01:55:57.64 |
+78:18:30.9 |
HIP 8908 |
7.77 |
| 2026-09-20 12:00 |
01:55:27.79 |
+78:19:27.2 |
HIP 8908 |
8.02 |
| 2026-09-21 00:00 |
01:54:57.71 |
+78:20:22.7 |
HIP 8908 |
8.62 |
| 2026-09-21 12:00 |
01:54:27.39 |
+78:21:17.1 |
HIP 8908 |
9.52 |
| 2026-09-22 00:00 |
01:53:56.84 |
+78:22:10.7 |
HIP 8908 |
10.63 |
| 2026-09-22 12:00 |
01:53:26.06 |
+78:23:03.3 |
HIP 8908 |
11.89 |
| 2026-09-23 00:00 |
01:52:55.06 |
+78:23:54.9 |
HIP 8500 |
12.64 |
| 2026-09-23 12:00 |
01:52:23.84 |
+78:24:45.5 |
HIP 8500 |
12.01 |
| 2026-09-24 00:00 |
01:51:52.40 |
+78:25:35.2 |
HIP 8500 |
11.60 |
| 2026-09-24 12:00 |
01:51:20.74 |
+78:26:23.9 |
HIP 8500 |
11.45 |
| 2026-09-25 00:00 |
01:50:48.87 |
+78:27:11.6 |
HIP 8500 |
11.56 |
| 2026-09-25 12:00 |
01:50:16.80 |
+78:27:58.3 |
HIP 8500 |
11.92 |
| 2026-09-26 00:00 |
01:49:44.51 |
+78:28:44.1 |
HIP 8500 |
12.52 |
| 2026-09-26 12:00 |
01:49:12.03 |
+78:29:28.8 |
HIP 8500 |
13.32 |
| 2026-09-27 00:00 |
01:48:39.35 |
+78:30:12.5 |
HIP 8500 |
14.28 |
| 2026-09-27 12:00 |
01:48:06.48 |
+78:30:55.2 |
HIP 8500 |
15.38 |
| 2026-09-28 00:00 |
01:47:33.41 |
+78:31:36.8 |
HIP 8500 |
16.60 |
| 2026-09-28 12:00 |
01:47:00.16 |
+78:32:17.4 |
HIP 8500 |
17.89 |
| 2026-09-29 00:00 |
01:46:26.73 |
+78:32:57.0 |
HIP 8500 |
19.26 |
| 2026-09-29 12:00 |
01:45:53.11 |
+78:33:35.6 |
HIP 8500 |
20.69 |
| 2026-09-30 00:00 |
01:45:19.32 |
+78:34:13.1 |
HIP 8500 |
22.15 |
| 2026-09-30 12:00 |
01:44:45.36 |
+78:34:49.6 |
HIP 8500 |
23.66 |
| 2026-10-01 00:00 |
01:44:11.24 |
+78:35:25.0 |
HIP 8500 |
25.20 |
| 2026-10-01 12:00 |
01:43:36.95 |
+78:35:59.3 |
HIP 8500 |
26.76 |
| 2026-10-02 00:00 |
01:43:02.50 |
+78:36:32.6 |
HIP 8500 |
28.34 |
| 2026-10-02 12:00 |
01:42:27.89 |
+78:37:04.8 |
HIP 8500 |
29.94 |
| 2026-10-03 00:00 |
01:41:53.14 |
+78:37:35.9 |
HIP 8500 |
31.55 |
| 2026-10-03 12:00 |
01:41:18.24 |
+78:38:05.9 |
HIP 7039 |
31.20 |
| 2026-10-04 00:00 |
01:40:43.20 |
+78:38:34.9 |
HIP 7039 |
29.47 |
| 2026-10-04 12:00 |
01:40:08.03 |
+78:39:02.7 |
HIP 7039 |
27.74 |
| 2026-10-05 00:00 |
01:39:32.72 |
+78:39:29.5 |
HIP 7039 |
26.01 |
| 2026-10-05 12:00 |
01:38:57.28 |
+78:39:55.1 |
HIP 7039 |
24.29 |
| 2026-10-06 00:00 |
01:38:21.72 |
+78:40:19.6 |
HIP 7039 |
22.58 |
| 2026-10-06 12:00 |
01:37:46.05 |
+78:40:43.1 |
HIP 7039 |
20.87 |
| 2026-10-07 00:00 |
01:37:10.26 |
+78:41:05.4 |
HIP 7039 |
19.18 |
| 2026-10-07 12:00 |
01:36:34.37 |
+78:41:26.6 |
HIP 7039 |
17.50 |
| 2026-10-08 00:00 |
01:35:58.38 |
+78:41:46.7 |
HIP 7039 |
15.84 |
| 2026-10-08 12:00 |
01:35:22.28 |
+78:42:05.6 |
HIP 7039 |
14.20 |
| 2026-10-09 00:00 |
01:34:46.10 |
+78:42:23.4 |
HIP 7039 |
12.60 |
| 2026-10-09 12:00 |
01:34:09.83 |
+78:42:40.1 |
HIP 7039 |
11.05 |
| 2026-10-10 00:00 |
01:33:33.48 |
+78:42:55.7 |
HIP 7039 |
9.58 |
| 2026-10-10 12:00 |
01:32:57.06 |
+78:43:10.1 |
HIP 7039 |
8.23 |
| 2026-10-11 00:00 |
01:32:20.57 |
+78:43:23.4 |
HIP 7039 |
7.08 |