| Parameter |
Value |
| Designation |
C/2026 A2 (Bok) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2026-12-22T08:45:07.773120Z |
| Orbit solution date (soln_date, UTC) |
2026-05-08T13:42:12Z |
| Obs used |
298 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
16.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2026-01-15T12:52:17.616000Z |
| Discovery magnitude (MPC) |
20.38 G |
| Discovery observatory (MPC) |
V00 · Kitt Peak-Bok |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2026-03-17.0000000 |
| e |
0.99754147 |
| q (au) |
1.937820 |
| a (au) |
788.202454 |
| i (deg) |
82.306438 |
| Ω (om, deg) |
206.591285 |
| ω (w, deg) |
155.937989 |
| M (ma, deg) |
359.987513 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.646 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.646 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.995 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
18:32:18.62 |
+67:43:45.4 |
HIP 90882 |
2.86 |
| 2026-05-12 12:00 |
18:32:17.82 |
+67:53:12.5 |
HIP 90882 |
6.60 |
| 2026-05-13 00:00 |
18:32:16.41 |
+68:02:37.4 |
HIP 90882 |
16.01 |
| 2026-05-13 12:00 |
18:32:14.38 |
+68:12:00.1 |
HIP 90902 |
24.88 |
| 2026-05-14 00:00 |
18:32:11.73 |
+68:21:20.6 |
HIP 90902 |
15.59 |
| 2026-05-14 12:00 |
18:32:08.44 |
+68:30:38.7 |
HIP 90902 |
6.51 |
| 2026-05-15 00:00 |
18:32:04.51 |
+68:39:54.5 |
HIP 90902 |
3.86 |
| 2026-05-15 12:00 |
18:31:59.92 |
+68:49:08.0 |
HIP 90902 |
12.59 |
| 2026-05-16 00:00 |
18:31:54.66 |
+68:58:18.9 |
HIP 90902 |
21.71 |
| 2026-05-16 12:00 |
18:31:48.74 |
+69:07:27.4 |
HIP 90535 |
18.41 |
| 2026-05-17 00:00 |
18:31:42.13 |
+69:16:33.4 |
HIP 90535 |
19.10 |
| 2026-05-17 12:00 |
18:31:34.83 |
+69:25:36.9 |
HIP 90535 |
23.54 |
| 2026-05-18 00:00 |
18:31:26.83 |
+69:34:37.7 |
HIP 90898 |
22.98 |
| 2026-05-18 12:00 |
18:31:18.12 |
+69:43:35.9 |
HIP 90898 |
14.68 |
| 2026-05-19 00:00 |
18:31:08.69 |
+69:52:31.5 |
HIP 90898 |
8.12 |
| 2026-05-19 12:00 |
18:30:58.54 |
+70:01:24.3 |
HIP 90893 |
8.38 |
| 2026-05-20 00:00 |
18:30:47.65 |
+70:10:14.3 |
HIP 90893 |
15.25 |
| 2026-05-20 12:00 |
18:30:36.01 |
+70:19:01.6 |
HIP 90893 |
23.48 |
| 2026-05-21 00:00 |
18:30:23.62 |
+70:27:46.0 |
HIP 90328 |
23.13 |
| 2026-05-21 12:00 |
18:30:10.46 |
+70:36:27.5 |
HIP 90328 |
24.50 |
| 2026-05-22 00:00 |
18:29:56.53 |
+70:45:06.2 |
HIP 90328 |
28.55 |
| 2026-05-22 12:00 |
18:29:41.82 |
+70:53:41.9 |
HIP 90829 |
28.45 |
| 2026-05-23 00:00 |
18:29:26.31 |
+71:02:14.5 |
HIP 90829 |
21.27 |
| 2026-05-23 12:00 |
18:29:09.99 |
+71:10:44.2 |
HIP 90829 |
15.71 |
| 2026-05-24 00:00 |
18:28:52.87 |
+71:19:10.8 |
HIP 90829 |
13.79 |
| 2026-05-24 12:00 |
18:28:34.92 |
+71:27:34.3 |
HIP 90829 |
16.75 |
| 2026-05-25 00:00 |
18:28:16.14 |
+71:35:54.6 |
HIP 90335 |
13.72 |
| 2026-05-25 12:00 |
18:27:56.51 |
+71:44:11.8 |
HIP 90335 |
9.58 |
| 2026-05-26 00:00 |
18:27:36.03 |
+71:52:25.8 |
HIP 90335 |
11.66 |
| 2026-05-26 12:00 |
18:27:14.68 |
+72:00:36.4 |
HIP 90335 |
17.84 |
| 2026-05-27 00:00 |
18:26:52.46 |
+72:08:43.8 |
HIP 90389 |
15.54 |
| 2026-05-27 12:00 |
18:26:29.36 |
+72:16:47.9 |
HIP 90389 |
7.45 |
| 2026-05-28 00:00 |
18:26:05.36 |
+72:24:48.6 |
HIP 90389 |
2.41 |
| 2026-05-28 12:00 |
18:25:40.46 |
+72:32:45.8 |
HIP 90389 |
9.52 |
| 2026-05-29 00:00 |
18:25:14.64 |
+72:40:39.6 |
HIP 90097 |
15.85 |
| 2026-05-29 12:00 |
18:24:47.89 |
+72:48:29.9 |
HIP 90097 |
8.73 |
| 2026-05-30 00:00 |
18:24:20.20 |
+72:56:16.7 |
HIP 90097 |
5.62 |
| 2026-05-30 12:00 |
18:23:51.57 |
+73:03:59.9 |
HIP 90097 |
10.71 |
| 2026-05-31 00:00 |
18:23:21.98 |
+73:11:39.4 |
HIP 90097 |
18.00 |
| 2026-05-31 12:00 |
18:22:51.43 |
+73:19:15.3 |
HIP 90097 |
25.63 |
| 2026-06-01 00:00 |
18:22:19.89 |
+73:26:47.5 |
HIP 90502 |
31.08 |
| 2026-06-01 12:00 |
18:21:47.37 |
+73:34:15.9 |
HIP 89971 |
28.66 |
| 2026-06-02 00:00 |
18:21:13.86 |
+73:41:40.5 |
HIP 89971 |
21.22 |