| Parameter |
Value |
| Designation |
C/2023 X4 (Hogan) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2024-05-24T19:34:19.804800Z |
| Orbit solution date (soln_date, UTC) |
2025-05-08T09:42:16Z |
| Obs used |
102 |
| NEO |
- |
| M1 |
13.200 |
| K1 |
8.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2023-12-13T07:58:38.409600Z |
| Discovery magnitude (MPC) |
19.86 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2024-06-16.0000000 |
| e |
0.63094701 |
| q (au) |
3.657863 |
| a (au) |
9.911484 |
| i (deg) |
11.594709 |
| Ω (om, deg) |
28.764969 |
| ω (w, deg) |
100.553292 |
| M (ma, deg) |
0.700722 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.631 + 4.372\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.631 |
| n |
4.372 |
| gf |
1.000 |
| gb |
-0.766 |
| 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) |
| 2026-05-12 00:00 |
14:12:27.84 |
-15:54:39.1 |
HIP 69455 |
20.29 |
| 2026-05-12 12:00 |
14:12:14.50 |
-15:53:57.6 |
HIP 69455 |
21.63 |
| 2026-05-13 00:00 |
14:12:01.23 |
-15:53:16.2 |
HIP 69455 |
23.35 |
| 2026-05-13 12:00 |
14:11:48.04 |
-15:52:35.0 |
HIP 69455 |
25.36 |
| 2026-05-14 00:00 |
14:11:34.94 |
-15:51:53.9 |
HIP 69455 |
27.59 |
| 2026-05-14 12:00 |
14:11:21.92 |
-15:51:13.1 |
HIP 69269 |
27.94 |
| 2026-05-15 00:00 |
14:11:08.98 |
-15:50:32.4 |
HIP 69269 |
27.94 |
| 2026-05-15 12:00 |
14:10:56.13 |
-15:49:52.0 |
HIP 69269 |
28.29 |
| 2026-05-16 00:00 |
14:10:43.37 |
-15:49:11.8 |
HIP 69269 |
28.97 |
| 2026-05-16 12:00 |
14:10:30.70 |
-15:48:31.9 |
HIP 69269 |
29.97 |
| 2026-05-17 00:00 |
14:10:18.12 |
-15:47:52.2 |
HIP 69269 |
31.23 |
| 2026-05-17 12:00 |
14:10:05.64 |
-15:47:12.7 |
HIP 69269 |
32.73 |
| 2026-05-18 00:00 |
14:09:53.26 |
-15:46:33.5 |
HIP 69269 |
34.43 |
| 2026-05-18 12:00 |
14:09:40.98 |
-15:45:54.6 |
HIP 69269 |
36.28 |
| 2026-05-19 00:00 |
14:09:28.79 |
-15:45:16.0 |
HIP 69269 |
38.27 |
| 2026-05-19 12:00 |
14:09:16.71 |
-15:44:37.7 |
HIP 68970 |
39.87 |
| 2026-05-20 00:00 |
14:09:04.73 |
-15:43:59.8 |
HIP 68970 |
38.24 |
| 2026-05-20 12:00 |
14:08:52.86 |
-15:43:22.1 |
HIP 68970 |
36.79 |
| 2026-05-21 00:00 |
14:08:41.10 |
-15:42:44.8 |
HIP 68970 |
35.53 |
| 2026-05-21 12:00 |
14:08:29.44 |
-15:42:07.8 |
HIP 68970 |
34.47 |
| 2026-05-22 00:00 |
14:08:17.90 |
-15:41:31.1 |
HIP 68970 |
33.64 |
| 2026-05-22 12:00 |
14:08:06.47 |
-15:40:54.9 |
HIP 68970 |
33.03 |
| 2026-05-23 00:00 |
14:07:55.15 |
-15:40:19.0 |
HIP 68970 |
32.66 |
| 2026-05-23 12:00 |
14:07:43.94 |
-15:39:43.4 |
HIP 68970 |
32.52 |
| 2026-05-24 00:00 |
14:07:32.85 |
-15:39:08.3 |
HIP 68970 |
32.61 |
| 2026-05-24 12:00 |
14:07:21.88 |
-15:38:33.5 |
HIP 68970 |
32.92 |
| 2026-05-25 00:00 |
14:07:11.03 |
-15:37:59.2 |
HIP 68970 |
33.45 |
| 2026-05-25 12:00 |
14:07:00.29 |
-15:37:25.2 |
HIP 68970 |
34.16 |
| 2026-05-26 00:00 |
14:06:49.68 |
-15:36:51.7 |
HIP 68970 |
35.05 |
| 2026-05-26 12:00 |
14:06:39.19 |
-15:36:18.6 |
HIP 68970 |
36.09 |
| 2026-05-27 00:00 |
14:06:28.83 |
-15:35:46.0 |
HIP 68729 |
34.65 |
| 2026-05-27 12:00 |
14:06:18.58 |
-15:35:13.7 |
HIP 68729 |
32.13 |
| 2026-05-28 00:00 |
14:06:08.47 |
-15:34:42.0 |
HIP 68729 |
29.64 |
| 2026-05-28 12:00 |
14:05:58.48 |
-15:34:10.7 |
HIP 68729 |
27.18 |
| 2026-05-29 00:00 |
14:05:48.62 |
-15:33:39.8 |
HIP 68729 |
24.75 |
| 2026-05-29 12:00 |
14:05:38.88 |
-15:33:09.4 |
HIP 68729 |
22.35 |
| 2026-05-30 00:00 |
14:05:29.28 |
-15:32:39.5 |
HIP 68729 |
19.99 |
| 2026-05-30 12:00 |
14:05:19.81 |
-15:32:10.1 |
HIP 68729 |
17.65 |
| 2026-05-31 00:00 |
14:05:10.47 |
-15:31:41.2 |
HIP 68729 |
15.36 |
| 2026-05-31 12:00 |
14:05:01.26 |
-15:31:12.7 |
HIP 68729 |
13.09 |
| 2026-06-01 00:00 |
14:04:52.19 |
-15:30:44.8 |
HIP 68729 |
10.86 |
| 2026-06-01 12:00 |
14:04:43.25 |
-15:30:17.4 |
HIP 68729 |
8.66 |
| 2026-06-02 00:00 |
14:04:34.44 |
-15:29:50.5 |
HIP 68729 |
6.51 |