| Parameter |
Value |
| Designation |
C/2022 U4 (Bok) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-08-03T16:19:50.327040Z |
| Orbit solution date (soln_date, UTC) |
2023-11-18T17:43:20Z |
| Obs used |
691 |
| NEO |
- |
| M1 |
12.200 |
| K1 |
8.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2022-10-26T11:34:51.024000Z |
| Discovery magnitude (MPC) |
20.21 G |
| Discovery observatory (MPC) |
V00 · Kitt Peak-Bok |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-04-13.0000000 |
| e |
0.99921142 |
| q (au) |
2.898398 |
| a (au) |
3675.478615 |
| i (deg) |
52.035423 |
| Ω (om, deg) |
132.928981 |
| ω (w, deg) |
89.007568 |
| M (ma, deg) |
359.999502 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.000 + 5.079\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.000 |
| n |
5.079 |
| gf |
1.000 |
| gb |
-0.736 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2022-01-07 |
2023-02-26 |
+3.2013 |
-2.039 |
| 2023-02-26 |
2023-08-02 |
-4.0345 |
+2.011 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-25 00:00 |
22:17:48.21 |
-32:14:15.6 |
HIP 110084 |
14.50 |
| 2026-09-25 12:00 |
22:17:39.49 |
-32:14:53.7 |
HIP 110084 |
14.17 |
| 2026-09-26 00:00 |
22:17:30.84 |
-32:15:31.0 |
HIP 110084 |
14.10 |
| 2026-09-26 12:00 |
22:17:22.27 |
-32:16:07.3 |
HIP 110084 |
14.31 |
| 2026-09-27 00:00 |
22:17:13.77 |
-32:16:42.7 |
HIP 110084 |
14.76 |
| 2026-09-27 12:00 |
22:17:05.35 |
-32:17:17.3 |
HIP 110084 |
15.43 |
| 2026-09-28 00:00 |
22:16:57.00 |
-32:17:50.9 |
HIP 110084 |
16.29 |
| 2026-09-28 12:00 |
22:16:48.73 |
-32:18:23.7 |
HIP 110084 |
17.30 |
| 2026-09-29 00:00 |
22:16:40.54 |
-32:18:55.6 |
HIP 110084 |
18.43 |
| 2026-09-29 12:00 |
22:16:32.43 |
-32:19:26.5 |
HIP 110084 |
19.65 |
| 2026-09-30 00:00 |
22:16:24.40 |
-32:19:56.6 |
HIP 110084 |
20.95 |
| 2026-09-30 12:00 |
22:16:16.45 |
-32:20:25.8 |
HIP 109816 |
21.56 |
| 2026-10-01 00:00 |
22:16:08.59 |
-32:20:54.1 |
HIP 109816 |
19.96 |
| 2026-10-01 12:00 |
22:16:00.80 |
-32:21:21.5 |
HIP 109816 |
18.39 |
| 2026-10-02 00:00 |
22:15:53.10 |
-32:21:48.1 |
HIP 109816 |
16.87 |
| 2026-10-02 12:00 |
22:15:45.49 |
-32:22:13.7 |
HIP 109816 |
15.39 |
| 2026-10-03 00:00 |
22:15:37.96 |
-32:22:38.5 |
HIP 109816 |
13.97 |
| 2026-10-03 12:00 |
22:15:30.51 |
-32:23:02.4 |
HIP 109816 |
12.62 |
| 2026-10-04 00:00 |
22:15:23.15 |
-32:23:25.4 |
HIP 109816 |
11.35 |
| 2026-10-04 12:00 |
22:15:15.88 |
-32:23:47.6 |
HIP 109816 |
10.17 |
| 2026-10-05 00:00 |
22:15:08.70 |
-32:24:08.8 |
HIP 109816 |
9.13 |
| 2026-10-05 12:00 |
22:15:01.61 |
-32:24:29.2 |
HIP 109816 |
8.25 |
| 2026-10-06 00:00 |
22:14:54.61 |
-32:24:48.8 |
HIP 109816 |
7.59 |
| 2026-10-06 12:00 |
22:14:47.69 |
-32:25:07.4 |
HIP 109816 |
7.18 |
| 2026-10-07 00:00 |
22:14:40.87 |
-32:25:25.2 |
HIP 109816 |
7.06 |
| 2026-10-07 12:00 |
22:14:34.15 |
-32:25:42.1 |
HIP 109816 |
7.22 |
| 2026-10-08 00:00 |
22:14:27.51 |
-32:25:58.2 |
HIP 109816 |
7.65 |
| 2026-10-08 12:00 |
22:14:20.97 |
-32:26:13.4 |
HIP 109816 |
8.28 |
| 2026-10-09 00:00 |
22:14:14.53 |
-32:26:27.8 |
HIP 109816 |
9.06 |
| 2026-10-09 12:00 |
22:14:08.18 |
-32:26:41.3 |
HIP 109816 |
9.95 |
| 2026-10-10 00:00 |
22:14:01.92 |
-32:26:53.9 |
HIP 109816 |
10.91 |
| 2026-10-10 12:00 |
22:13:55.77 |
-32:27:05.7 |
HIP 109816 |
11.92 |
| 2026-10-11 00:00 |
22:13:49.71 |
-32:27:16.7 |
HIP 109816 |
12.96 |
| 2026-10-11 12:00 |
22:13:43.75 |
-32:27:26.8 |
HIP 109816 |
14.02 |
| 2026-10-12 00:00 |
22:13:37.88 |
-32:27:36.1 |
HIP 109816 |
15.09 |
| 2026-10-12 12:00 |
22:13:32.12 |
-32:27:44.5 |
HIP 109816 |
16.15 |
| 2026-10-13 00:00 |
22:13:26.45 |
-32:27:52.2 |
HIP 109605 |
16.72 |
| 2026-10-13 12:00 |
22:13:20.89 |
-32:27:59.0 |
HIP 109605 |
15.56 |
| 2026-10-14 00:00 |
22:13:15.43 |
-32:28:05.0 |
HIP 109605 |
14.42 |
| 2026-10-14 12:00 |
22:13:10.07 |
-32:28:10.1 |
HIP 109605 |
13.32 |
| 2026-10-15 00:00 |
22:13:04.81 |
-32:28:14.5 |
HIP 109605 |
12.24 |
| 2026-10-15 12:00 |
22:12:59.65 |
-32:28:18.0 |
HIP 109605 |
11.20 |
| 2026-10-16 00:00 |
22:12:54.59 |
-32:28:20.8 |
HIP 109605 |
10.19 |