| 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) |
| 2026-07-29 00:00 |
09:08:16.80 |
-74:38:44.0 |
HIP 44699 |
9.52 |
| 2026-07-29 12:00 |
09:08:41.01 |
-74:38:23.5 |
HIP 44699 |
10.96 |
| 2026-07-30 00:00 |
09:09:05.22 |
-74:38:03.6 |
HIP 44699 |
12.43 |
| 2026-07-30 12:00 |
09:09:29.42 |
-74:37:44.3 |
HIP 44699 |
13.94 |
| 2026-07-31 00:00 |
09:09:53.62 |
-74:37:25.6 |
HIP 44699 |
15.47 |
| 2026-07-31 12:00 |
09:10:17.82 |
-74:37:07.6 |
HIP 45169 |
16.32 |
| 2026-08-01 00:00 |
09:10:42.01 |
-74:36:50.2 |
HIP 45169 |
15.90 |
| 2026-08-01 12:00 |
09:11:06.20 |
-74:36:33.5 |
HIP 45169 |
15.63 |
| 2026-08-02 00:00 |
09:11:30.38 |
-74:36:17.3 |
HIP 45169 |
15.51 |
| 2026-08-02 12:00 |
09:11:54.56 |
-74:36:01.8 |
HIP 45169 |
15.55 |
| 2026-08-03 00:00 |
09:12:18.72 |
-74:35:47.0 |
HIP 45169 |
15.75 |
| 2026-08-03 12:00 |
09:12:42.89 |
-74:35:32.7 |
HIP 45169 |
16.09 |
| 2026-08-04 00:00 |
09:13:07.04 |
-74:35:19.1 |
HIP 45169 |
16.58 |
| 2026-08-04 12:00 |
09:13:31.18 |
-74:35:06.1 |
HIP 45169 |
17.19 |
| 2026-08-05 00:00 |
09:13:55.32 |
-74:34:53.8 |
HIP 45585 |
16.78 |
| 2026-08-05 12:00 |
09:14:19.44 |
-74:34:42.0 |
HIP 45585 |
15.59 |
| 2026-08-06 00:00 |
09:14:43.56 |
-74:34:30.9 |
HIP 45585 |
14.47 |
| 2026-08-06 12:00 |
09:15:07.66 |
-74:34:20.5 |
HIP 45585 |
13.44 |
| 2026-08-07 00:00 |
09:15:31.75 |
-74:34:10.6 |
HIP 45585 |
12.52 |
| 2026-08-07 12:00 |
09:15:55.83 |
-74:34:01.4 |
HIP 45585 |
11.75 |
| 2026-08-08 00:00 |
09:16:19.90 |
-74:33:52.9 |
HIP 45585 |
11.14 |
| 2026-08-08 12:00 |
09:16:43.95 |
-74:33:45.0 |
HIP 45585 |
10.73 |
| 2026-08-09 00:00 |
09:17:07.98 |
-74:33:37.7 |
HIP 45585 |
10.53 |
| 2026-08-09 12:00 |
09:17:32.00 |
-74:33:31.0 |
HIP 45585 |
10.57 |
| 2026-08-10 00:00 |
09:17:56.01 |
-74:33:25.0 |
HIP 45585 |
10.83 |
| 2026-08-10 12:00 |
09:18:19.99 |
-74:33:19.6 |
HIP 45585 |
11.30 |
| 2026-08-11 00:00 |
09:18:43.96 |
-74:33:14.8 |
HIP 45585 |
11.95 |
| 2026-08-11 12:00 |
09:19:07.91 |
-74:33:10.7 |
HIP 45585 |
12.76 |
| 2026-08-12 00:00 |
09:19:31.84 |
-74:33:07.3 |
HIP 45585 |
13.70 |
| 2026-08-12 12:00 |
09:19:55.74 |
-74:33:04.4 |
HIP 45585 |
14.74 |
| 2026-08-13 00:00 |
09:20:19.63 |
-74:33:02.2 |
HIP 46048 |
15.33 |
| 2026-08-13 12:00 |
09:20:43.49 |
-74:33:00.6 |
HIP 46048 |
14.04 |
| 2026-08-14 00:00 |
09:21:07.33 |
-74:32:59.7 |
HIP 46048 |
12.83 |
| 2026-08-14 12:00 |
09:21:31.15 |
-74:32:59.4 |
HIP 46048 |
11.72 |
| 2026-08-15 00:00 |
09:21:54.94 |
-74:32:59.7 |
HIP 46048 |
10.74 |
| 2026-08-15 12:00 |
09:22:18.70 |
-74:33:00.7 |
HIP 46048 |
9.93 |
| 2026-08-16 00:00 |
09:22:42.44 |
-74:33:02.3 |
HIP 46048 |
9.34 |
| 2026-08-16 12:00 |
09:23:06.15 |
-74:33:04.5 |
HIP 46048 |
9.00 |
| 2026-08-17 00:00 |
09:23:29.84 |
-74:33:07.3 |
HIP 46048 |
8.95 |
| 2026-08-17 12:00 |
09:23:53.49 |
-74:33:10.8 |
HIP 46048 |
9.18 |
| 2026-08-18 00:00 |
09:24:17.12 |
-74:33:14.9 |
HIP 46048 |
9.68 |
| 2026-08-18 12:00 |
09:24:40.71 |
-74:33:19.7 |
HIP 46048 |
10.41 |
| 2026-08-19 00:00 |
09:25:04.27 |
-74:33:25.0 |
HIP 46048 |
11.32 |