| Parameter |
Value |
| Designation |
C/2026 H3 (Bok) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2026-05-23T01:14:31.597440Z |
| Orbit solution date (soln_date, UTC) |
2026-05-19T10:12:02Z |
| Obs used |
59 |
| NEO |
- |
| M1 |
7.200 |
| K1 |
11.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2026-04-27T11:09:21.312000Z |
| Discovery magnitude (MPC) |
20.88 G |
| Discovery observatory (MPC) |
V00 · Kitt Peak-Bok |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2026-03-05.0000000 |
| e |
1.00372394 |
| q (au) |
7.728219 |
| a (au) |
-2075.279272 |
| i (deg) |
142.567608 |
| Ω (om, deg) |
352.490926 |
| ω (w, deg) |
98.493167 |
| M (ma, deg) |
-0.000824 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.113 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.113 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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 |
16:16:00.62 |
+17:51:49.3 |
HIP 79723 |
6.63 |
| 2026-07-29 12:00 |
16:15:44.07 |
+17:49:50.4 |
HIP 79723 |
8.43 |
| 2026-07-30 00:00 |
16:15:27.68 |
+17:47:50.8 |
HIP 79723 |
11.67 |
| 2026-07-30 12:00 |
16:15:11.45 |
+17:45:50.4 |
HIP 79723 |
15.44 |
| 2026-07-31 00:00 |
16:14:55.37 |
+17:43:49.4 |
HIP 79723 |
19.43 |
| 2026-07-31 12:00 |
16:14:39.44 |
+17:41:47.7 |
HIP 79723 |
23.50 |
| 2026-08-01 00:00 |
16:14:23.68 |
+17:39:45.3 |
HIP 79723 |
27.61 |
| 2026-08-01 12:00 |
16:14:08.07 |
+17:37:42.2 |
HIP 79389 |
30.35 |
| 2026-08-02 00:00 |
16:13:52.62 |
+17:35:38.5 |
HIP 79389 |
27.83 |
| 2026-08-02 12:00 |
16:13:37.32 |
+17:33:34.2 |
HIP 79389 |
25.79 |
| 2026-08-03 00:00 |
16:13:22.19 |
+17:31:29.3 |
HIP 79389 |
24.35 |
| 2026-08-03 12:00 |
16:13:07.21 |
+17:29:23.7 |
HIP 79389 |
23.59 |
| 2026-08-04 00:00 |
16:12:52.38 |
+17:27:17.6 |
HIP 79389 |
23.57 |
| 2026-08-04 12:00 |
16:12:37.72 |
+17:25:10.8 |
HIP 79389 |
24.28 |
| 2026-08-05 00:00 |
16:12:23.21 |
+17:23:03.5 |
HIP 79389 |
25.64 |
| 2026-08-05 12:00 |
16:12:08.87 |
+17:20:55.6 |
HIP 79338 |
24.12 |
| 2026-08-06 00:00 |
16:11:54.68 |
+17:18:47.2 |
HIP 79338 |
20.97 |
| 2026-08-06 12:00 |
16:11:40.64 |
+17:16:38.3 |
HIP 79338 |
18.15 |
| 2026-08-07 00:00 |
16:11:26.77 |
+17:14:28.8 |
HIP 79338 |
15.84 |
| 2026-08-07 12:00 |
16:11:13.06 |
+17:12:18.8 |
HIP 79338 |
14.24 |
| 2026-08-08 00:00 |
16:10:59.50 |
+17:10:08.3 |
HIP 79338 |
13.61 |
| 2026-08-08 12:00 |
16:10:46.11 |
+17:07:57.4 |
HIP 79338 |
14.03 |
| 2026-08-09 00:00 |
16:10:32.87 |
+17:05:45.9 |
HIP 79338 |
15.41 |
| 2026-08-09 12:00 |
16:10:19.79 |
+17:03:34.0 |
HIP 79338 |
17.50 |
| 2026-08-10 00:00 |
16:10:06.87 |
+17:01:21.7 |
HIP 79181 |
14.57 |
| 2026-08-10 12:00 |
16:09:54.11 |
+16:59:08.9 |
HIP 79181 |
11.37 |
| 2026-08-11 00:00 |
16:09:41.51 |
+16:56:55.7 |
HIP 79181 |
8.63 |
| 2026-08-11 12:00 |
16:09:29.07 |
+16:54:42.1 |
HIP 79181 |
6.90 |
| 2026-08-12 00:00 |
16:09:16.79 |
+16:52:28.2 |
HIP 79181 |
6.92 |
| 2026-08-12 12:00 |
16:09:04.66 |
+16:50:13.8 |
HIP 79181 |
8.65 |
| 2026-08-13 00:00 |
16:08:52.70 |
+16:47:59.1 |
HIP 79181 |
11.30 |
| 2026-08-13 12:00 |
16:08:40.89 |
+16:45:44.0 |
HIP 79024 |
13.33 |
| 2026-08-14 00:00 |
16:08:29.24 |
+16:43:28.6 |
HIP 79024 |
10.45 |
| 2026-08-14 12:00 |
16:08:17.75 |
+16:41:12.8 |
HIP 79024 |
8.20 |
| 2026-08-15 00:00 |
16:08:06.42 |
+16:38:56.7 |
HIP 79024 |
7.14 |
| 2026-08-15 12:00 |
16:07:55.24 |
+16:36:40.4 |
HIP 79024 |
7.75 |
| 2026-08-16 00:00 |
16:07:44.22 |
+16:34:23.7 |
HIP 79024 |
9.69 |
| 2026-08-16 12:00 |
16:07:33.36 |
+16:32:06.8 |
HIP 79024 |
12.32 |
| 2026-08-17 00:00 |
16:07:22.66 |
+16:29:49.6 |
HIP 78936 |
11.62 |
| 2026-08-17 12:00 |
16:07:12.11 |
+16:27:32.2 |
HIP 78936 |
8.23 |
| 2026-08-18 00:00 |
16:07:01.71 |
+16:25:14.5 |
HIP 78936 |
4.90 |
| 2026-08-18 12:00 |
16:06:51.48 |
+16:22:56.6 |
HIP 78936 |
1.81 |
| 2026-08-19 00:00 |
16:06:41.39 |
+16:20:38.5 |
HIP 78936 |
2.23 |