| Parameter |
Value |
| Designation |
C/2026 A2 (Bok) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2026-12-22T08:58:54.552000Z |
| Orbit solution date (soln_date, UTC) |
2026-03-31T09:42:29Z |
| Obs used |
187 |
| NEO |
- |
| M1 |
6.400 |
| K1 |
17.000 |
| 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) |
2026-02-24.0000000 |
| e |
0.99745652 |
| q (au) |
1.937724 |
| a (au) |
761.839834 |
| i (deg) |
82.306572 |
| Ω (om, deg) |
206.591293 |
| ω (w, deg) |
155.942428 |
| M (ma, deg) |
359.985874 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.682 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.682 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.526 |
| 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) |
| 2026-03-26 00:00 |
18:04:07.76 |
+51:38:21.9 |
HIP 88536 |
15.66 |
| 2026-03-26 12:00 |
18:04:37.33 |
+51:48:36.2 |
HIP 88536 |
4.49 |
| 2026-03-27 00:00 |
18:05:06.75 |
+51:58:51.4 |
HIP 88606 |
4.22 |
| 2026-03-27 12:00 |
18:05:36.02 |
+52:09:07.7 |
HIP 88606 |
12.34 |
| 2026-03-28 00:00 |
18:06:05.14 |
+52:19:24.9 |
HIP 88606 |
23.21 |
| 2026-03-28 12:00 |
18:06:34.10 |
+52:29:43.0 |
HIP 88807 |
27.16 |
| 2026-03-29 00:00 |
18:07:02.91 |
+52:40:02.1 |
HIP 88807 |
15.95 |
| 2026-03-29 12:00 |
18:07:31.56 |
+52:50:22.0 |
HIP 88807 |
4.75 |
| 2026-03-30 00:00 |
18:08:00.04 |
+53:00:42.7 |
HIP 88807 |
6.46 |
| 2026-03-30 12:00 |
18:08:28.37 |
+53:11:04.3 |
HIP 88784 |
9.27 |
| 2026-03-31 00:00 |
18:08:56.52 |
+53:21:26.6 |
HIP 89073 |
16.71 |
| 2026-03-31 12:00 |
18:09:24.51 |
+53:31:49.8 |
HIP 89074 |
12.13 |
| 2026-04-01 00:00 |
18:09:52.33 |
+53:42:13.6 |
HIP 89074 |
14.51 |
| 2026-04-01 12:00 |
18:10:19.97 |
+53:52:38.2 |
HIP 89074 |
22.92 |
| 2026-04-02 00:00 |
18:10:47.44 |
+54:03:03.4 |
HIP 89047 |
14.29 |
| 2026-04-02 12:00 |
18:11:14.72 |
+54:13:29.3 |
HIP 89047 |
7.30 |
| 2026-04-03 00:00 |
18:11:41.83 |
+54:23:55.7 |
HIP 89047 |
12.28 |
| 2026-04-03 12:00 |
18:12:08.75 |
+54:34:22.8 |
HIP 89243 |
12.62 |
| 2026-04-04 00:00 |
18:12:35.49 |
+54:44:50.4 |
HIP 89243 |
1.50 |
| 2026-04-04 12:00 |
18:13:02.03 |
+54:55:18.6 |
HIP 89243 |
9.68 |
| 2026-04-05 00:00 |
18:13:28.38 |
+55:05:47.2 |
HIP 89243 |
20.82 |
| 2026-04-05 12:00 |
18:13:54.53 |
+55:16:16.3 |
HIP 89243 |
31.95 |
| 2026-04-06 00:00 |
18:14:20.49 |
+55:26:45.9 |
HIP 89575 |
24.87 |
| 2026-04-06 12:00 |
18:14:46.24 |
+55:37:15.8 |
HIP 89575 |
16.94 |
| 2026-04-07 00:00 |
18:15:11.78 |
+55:47:46.1 |
HIP 89575 |
14.30 |
| 2026-04-07 12:00 |
18:15:37.12 |
+55:58:16.8 |
HIP 89575 |
19.23 |
| 2026-04-08 00:00 |
18:16:02.24 |
+56:08:47.8 |
HIP 89575 |
27.98 |
| 2026-04-08 12:00 |
18:16:27.15 |
+56:19:19.0 |
HIP 89401 |
21.68 |
| 2026-04-09 00:00 |
18:16:51.83 |
+56:29:50.5 |
HIP 89401 |
18.84 |
| 2026-04-09 12:00 |
18:17:16.30 |
+56:40:22.2 |
HIP 89473 |
19.25 |
| 2026-04-10 00:00 |
18:17:40.53 |
+56:50:54.0 |
HIP 89473 |
17.77 |
| 2026-04-10 12:00 |
18:18:04.54 |
+57:01:26.0 |
HIP 89473 |
22.41 |
| 2026-04-11 00:00 |
18:18:28.31 |
+57:11:58.1 |
HIP 89455 |
26.51 |
| 2026-04-11 12:00 |
18:18:51.85 |
+57:22:30.3 |
HIP 89455 |
28.43 |
| 2026-04-12 00:00 |
18:19:15.14 |
+57:33:02.5 |
HIP 89670 |
23.00 |
| 2026-04-12 12:00 |
18:19:38.18 |
+57:43:34.8 |
HIP 89670 |
16.84 |
| 2026-04-13 00:00 |
18:20:00.98 |
+57:54:06.9 |
HIP 89715 |
13.20 |
| 2026-04-13 12:00 |
18:20:23.52 |
+58:04:39.1 |
HIP 89715 |
15.10 |
| 2026-04-14 00:00 |
18:20:45.81 |
+58:15:11.1 |
HIP 89715 |
22.79 |
| 2026-04-14 12:00 |
18:21:07.83 |
+58:25:43.0 |
HIP 89901 |
14.32 |
| 2026-04-15 00:00 |
18:21:29.58 |
+58:36:14.7 |
HIP 89901 |
7.05 |
| 2026-04-15 12:00 |
18:21:51.07 |
+58:46:46.1 |
HIP 89974 |
5.47 |
| 2026-04-16 00:00 |
18:22:12.28 |
+58:57:17.4 |
HIP 90092 |
7.51 |