| Parameter |
Value |
| Designation |
C/2019 K4 (Ye) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-06-16T10:03:46.733760Z |
| Orbit solution date (soln_date, UTC) |
2021-05-02T23:42:41Z |
| Obs used |
609 |
| NEO |
- |
| M1 |
12.900 |
| K1 |
8.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2019-05-30T11:03:04.003200Z |
| Discovery magnitude (MPC) |
17.14 r |
| Discovery observatory (MPC) |
I41 · Palomar Mountain–ZTF |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-08-25.0000000 |
| e |
0.99906130 |
| q (au) |
2.259417 |
| a (au) |
2406.958686 |
| i (deg) |
105.305274 |
| Ω (om, deg) |
180.165129 |
| ω (w, deg) |
139.772154 |
| M (ma, deg) |
0.000581 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.560 + 5.292\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.560 |
| n |
5.292 |
| gf |
0.999 |
| gb |
-0.735 |
| k |
0.992 |
| 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) |
| 2026-05-12 00:00 |
08:14:23.25 |
-77:25:56.8 |
HIP 40888 |
20.63 |
| 2026-05-12 12:00 |
08:14:36.09 |
-77:24:19.2 |
HIP 40888 |
20.28 |
| 2026-05-13 00:00 |
08:14:49.10 |
-77:22:41.7 |
HIP 40888 |
20.07 |
| 2026-05-13 12:00 |
08:15:02.29 |
-77:21:04.5 |
HIP 40081 |
19.75 |
| 2026-05-14 00:00 |
08:15:15.64 |
-77:19:27.6 |
HIP 40081 |
19.05 |
| 2026-05-14 12:00 |
08:15:29.17 |
-77:17:50.9 |
HIP 40081 |
18.51 |
| 2026-05-15 00:00 |
08:15:42.86 |
-77:16:14.5 |
HIP 40081 |
18.14 |
| 2026-05-15 12:00 |
08:15:56.72 |
-77:14:38.4 |
HIP 40081 |
17.96 |
| 2026-05-16 00:00 |
08:16:10.75 |
-77:13:02.5 |
HIP 40081 |
17.96 |
| 2026-05-16 12:00 |
08:16:24.94 |
-77:11:26.9 |
HIP 40702 |
17.72 |
| 2026-05-17 00:00 |
08:16:39.29 |
-77:09:51.6 |
HIP 40702 |
15.95 |
| 2026-05-17 12:00 |
08:16:53.80 |
-77:08:16.5 |
HIP 40702 |
14.17 |
| 2026-05-18 00:00 |
08:17:08.47 |
-77:06:41.8 |
HIP 40702 |
12.40 |
| 2026-05-18 12:00 |
08:17:23.29 |
-77:05:07.4 |
HIP 40702 |
10.63 |
| 2026-05-19 00:00 |
08:17:38.27 |
-77:03:33.3 |
HIP 40702 |
8.87 |
| 2026-05-19 12:00 |
08:17:53.40 |
-77:01:59.4 |
HIP 40702 |
7.12 |
| 2026-05-20 00:00 |
08:18:08.68 |
-77:00:25.9 |
HIP 40702 |
5.39 |
| 2026-05-20 12:00 |
08:18:24.11 |
-76:58:52.8 |
HIP 40702 |
3.70 |
| 2026-05-21 00:00 |
08:18:39.69 |
-76:57:19.9 |
HIP 40702 |
2.18 |
| 2026-05-21 12:00 |
08:18:55.41 |
-76:55:47.4 |
HIP 40702 |
1.49 |
| 2026-05-22 00:00 |
08:19:11.27 |
-76:54:15.2 |
HIP 40702 |
2.45 |
| 2026-05-22 12:00 |
08:19:27.28 |
-76:52:43.3 |
HIP 40702 |
4.03 |
| 2026-05-23 00:00 |
08:19:43.43 |
-76:51:11.8 |
HIP 40702 |
5.72 |
| 2026-05-23 12:00 |
08:19:59.71 |
-76:49:40.6 |
HIP 40702 |
7.46 |
| 2026-05-24 00:00 |
08:20:16.13 |
-76:48:09.7 |
HIP 40702 |
9.22 |
| 2026-05-24 12:00 |
08:20:32.69 |
-76:46:39.3 |
HIP 40702 |
10.99 |
| 2026-05-25 00:00 |
08:20:49.38 |
-76:45:09.1 |
HIP 40702 |
12.76 |
| 2026-05-25 12:00 |
08:21:06.20 |
-76:43:39.4 |
HIP 40702 |
14.53 |
| 2026-05-26 00:00 |
08:21:23.15 |
-76:42:09.9 |
HIP 40702 |
16.31 |
| 2026-05-26 12:00 |
08:21:40.23 |
-76:40:40.9 |
HIP 41079 |
15.17 |
| 2026-05-27 00:00 |
08:21:57.44 |
-76:39:12.2 |
HIP 41079 |
13.48 |
| 2026-05-27 12:00 |
08:22:14.77 |
-76:37:43.9 |
HIP 41079 |
11.82 |
| 2026-05-28 00:00 |
08:22:32.23 |
-76:36:16.0 |
HIP 41079 |
10.22 |
| 2026-05-28 12:00 |
08:22:49.81 |
-76:34:48.5 |
HIP 41079 |
8.68 |
| 2026-05-29 00:00 |
08:23:07.51 |
-76:33:21.3 |
HIP 41079 |
7.27 |
| 2026-05-29 12:00 |
08:23:25.33 |
-76:31:54.5 |
HIP 41079 |
6.07 |
| 2026-05-30 00:00 |
08:23:43.27 |
-76:30:28.1 |
HIP 41079 |
5.21 |
| 2026-05-30 12:00 |
08:24:01.33 |
-76:29:02.2 |
HIP 41079 |
4.90 |
| 2026-05-31 00:00 |
08:24:19.50 |
-76:27:36.6 |
HIP 41079 |
5.23 |
| 2026-05-31 12:00 |
08:24:37.79 |
-76:26:11.4 |
HIP 41079 |
6.09 |
| 2026-06-01 00:00 |
08:24:56.19 |
-76:24:46.6 |
HIP 41079 |
7.30 |
| 2026-06-01 12:00 |
08:25:14.70 |
-76:23:22.2 |
HIP 41079 |
8.72 |
| 2026-06-02 00:00 |
08:25:33.32 |
-76:21:58.2 |
HIP 41079 |
10.25 |