| 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 |
-4.0360 |
+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) |
| 2026-03-26 00:00 |
22:23:55.56 |
-24:31:32.9 |
HIP 110529 |
15.29 |
| 2026-03-26 12:00 |
22:24:09.63 |
-24:31:26.7 |
HIP 110529 |
16.82 |
| 2026-03-27 00:00 |
22:24:23.64 |
-24:31:21.1 |
HIP 110529 |
18.76 |
| 2026-03-27 12:00 |
22:24:37.60 |
-24:31:16.0 |
HIP 110695 |
18.95 |
| 2026-03-28 00:00 |
22:24:51.51 |
-24:31:11.5 |
HIP 110695 |
16.75 |
| 2026-03-28 12:00 |
22:25:05.36 |
-24:31:07.5 |
HIP 110695 |
14.91 |
| 2026-03-29 00:00 |
22:25:19.15 |
-24:31:04.2 |
HIP 110747 |
12.71 |
| 2026-03-29 12:00 |
22:25:32.89 |
-24:31:01.4 |
HIP 110747 |
9.84 |
| 2026-03-30 00:00 |
22:25:46.58 |
-24:30:59.1 |
HIP 110747 |
7.21 |
| 2026-03-30 12:00 |
22:26:00.20 |
-24:30:57.5 |
HIP 110747 |
5.16 |
| 2026-03-31 00:00 |
22:26:13.77 |
-24:30:56.4 |
HIP 110747 |
4.54 |
| 2026-03-31 12:00 |
22:26:27.28 |
-24:30:55.9 |
HIP 110747 |
5.80 |
| 2026-04-01 00:00 |
22:26:40.73 |
-24:30:56.0 |
HIP 110747 |
8.09 |
| 2026-04-01 12:00 |
22:26:54.13 |
-24:30:56.7 |
HIP 110747 |
10.76 |
| 2026-04-02 00:00 |
22:27:07.46 |
-24:30:58.0 |
HIP 110747 |
13.59 |
| 2026-04-02 12:00 |
22:27:20.74 |
-24:30:59.9 |
HIP 110747 |
16.47 |
| 2026-04-03 00:00 |
22:27:33.95 |
-24:31:02.4 |
HIP 110747 |
19.39 |
| 2026-04-03 12:00 |
22:27:47.11 |
-24:31:05.4 |
HIP 110747 |
22.32 |
| 2026-04-04 00:00 |
22:28:00.20 |
-24:31:09.1 |
HIP 110747 |
25.25 |
| 2026-04-04 12:00 |
22:28:13.24 |
-24:31:13.4 |
HIP 110966 |
25.30 |
| 2026-04-05 00:00 |
22:28:26.21 |
-24:31:18.3 |
HIP 110966 |
24.38 |
| 2026-04-05 12:00 |
22:28:39.11 |
-24:31:23.8 |
HIP 110966 |
23.80 |
| 2026-04-06 00:00 |
22:28:51.96 |
-24:31:29.9 |
HIP 111083 |
21.63 |
| 2026-04-06 12:00 |
22:29:04.74 |
-24:31:36.6 |
HIP 111083 |
19.10 |
| 2026-04-07 00:00 |
22:29:17.46 |
-24:31:44.0 |
HIP 111083 |
16.70 |
| 2026-04-07 12:00 |
22:29:30.11 |
-24:31:52.0 |
HIP 111083 |
14.49 |
| 2026-04-08 00:00 |
22:29:42.70 |
-24:32:00.6 |
HIP 111083 |
12.55 |
| 2026-04-08 12:00 |
22:29:55.22 |
-24:32:09.8 |
HIP 111083 |
11.01 |
| 2026-04-09 00:00 |
22:30:07.68 |
-24:32:19.7 |
HIP 111083 |
10.06 |
| 2026-04-09 12:00 |
22:30:20.07 |
-24:32:30.2 |
HIP 111083 |
9.84 |
| 2026-04-10 00:00 |
22:30:32.39 |
-24:32:41.3 |
HIP 111083 |
10.40 |
| 2026-04-10 12:00 |
22:30:44.64 |
-24:32:53.1 |
HIP 111083 |
11.61 |
| 2026-04-11 00:00 |
22:30:56.83 |
-24:33:05.5 |
HIP 111083 |
13.29 |
| 2026-04-11 12:00 |
22:31:08.95 |
-24:33:18.6 |
HIP 111083 |
15.27 |
| 2026-04-12 00:00 |
22:31:21.00 |
-24:33:32.3 |
HIP 111083 |
17.45 |
| 2026-04-12 12:00 |
22:31:32.98 |
-24:33:46.7 |
HIP 111289 |
16.20 |
| 2026-04-13 00:00 |
22:31:44.89 |
-24:34:01.8 |
HIP 111289 |
13.50 |
| 2026-04-13 12:00 |
22:31:56.72 |
-24:34:17.5 |
HIP 111289 |
10.83 |
| 2026-04-14 00:00 |
22:32:08.49 |
-24:34:33.8 |
HIP 111289 |
8.19 |
| 2026-04-14 12:00 |
22:32:20.18 |
-24:34:50.9 |
HIP 111289 |
5.60 |
| 2026-04-15 00:00 |
22:32:31.81 |
-24:35:08.6 |
HIP 111289 |
3.16 |
| 2026-04-15 12:00 |
22:32:43.35 |
-24:35:26.9 |
HIP 111289 |
1.66 |
| 2026-04-16 00:00 |
22:32:54.83 |
-24:35:46.0 |
HIP 111289 |
3.06 |