| Parameter |
Value |
| Designation |
C/2026 B2 (Sun-Gao) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2026-01-10T03:02:20.037120Z |
| Orbit solution date (soln_date, UTC) |
2026-03-31T09:42:30Z |
| Obs used |
177 |
| NEO |
- |
| M1 |
14.000 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2026-01-19T00:03:36.864000Z |
| Discovery magnitude (MPC) |
15.50 G |
| Discovery observatory (MPC) |
N86 · Xingming Observatory-KATS, Nanshan |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2026-02-09.0000000 |
| e |
0.99795008 |
| q (au) |
1.284352 |
| a (au) |
626.536734 |
| i (deg) |
59.577416 |
| Ω (om, deg) |
234.639325 |
| ω (w, deg) |
47.306465 |
| M (ma, deg) |
0.001877 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.863 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.863 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.513 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2026-01-19 |
2026-03-18 |
-7.6998 |
+0.483 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
22:55:29.80 |
+32:28:52.1 |
HIP 113342 |
28.01 |
| 2026-03-26 12:00 |
22:57:07.71 |
+32:37:03.6 |
HIP 113342 |
25.16 |
| 2026-03-27 00:00 |
22:58:45.32 |
+32:45:10.4 |
HIP 113633 |
29.69 |
| 2026-03-27 12:00 |
23:00:22.63 |
+32:53:12.6 |
HIP 113618 |
20.98 |
| 2026-03-28 00:00 |
23:01:59.64 |
+33:01:10.3 |
HIP 113728 |
19.57 |
| 2026-03-28 12:00 |
23:03:36.34 |
+33:09:03.4 |
HIP 113985 |
22.63 |
| 2026-03-29 00:00 |
23:05:12.74 |
+33:16:52.1 |
HIP 113985 |
6.73 |
| 2026-03-29 12:00 |
23:06:48.83 |
+33:24:36.3 |
HIP 114116 |
22.52 |
| 2026-03-30 00:00 |
23:08:24.61 |
+33:32:16.1 |
HIP 114404 |
25.71 |
| 2026-03-30 12:00 |
23:10:00.09 |
+33:39:51.5 |
HIP 114404 |
6.48 |
| 2026-03-31 00:00 |
23:11:35.25 |
+33:47:22.5 |
HIP 114498 |
4.79 |
| 2026-03-31 12:00 |
23:13:10.11 |
+33:54:49.2 |
HIP 114663 |
21.85 |
| 2026-04-01 00:00 |
23:14:44.65 |
+34:02:11.6 |
HIP 114663 |
19.10 |
| 2026-04-01 12:00 |
23:16:18.89 |
+34:09:29.8 |
HIP 114915 |
16.63 |
| 2026-04-02 00:00 |
23:17:52.81 |
+34:16:43.8 |
HIP 115017 |
14.12 |
| 2026-04-02 12:00 |
23:19:26.42 |
+34:23:53.6 |
HIP 115148 |
23.70 |
| 2026-04-03 00:00 |
23:20:59.72 |
+34:30:59.2 |
HIP 115357 |
14.36 |
| 2026-04-03 12:00 |
23:22:32.70 |
+34:38:00.8 |
HIP 115357 |
7.46 |
| 2026-04-04 00:00 |
23:24:05.37 |
+34:44:58.3 |
HIP 115471 |
26.94 |
| 2026-04-04 12:00 |
23:25:37.73 |
+34:51:51.7 |
HIP 115539 |
32.73 |
| 2026-04-05 00:00 |
23:27:09.77 |
+34:58:41.2 |
HIP 115807 |
33.36 |
| 2026-04-05 12:00 |
23:28:41.49 |
+35:05:26.7 |
HIP 115979 |
15.28 |
| 2026-04-06 00:00 |
23:30:12.90 |
+35:12:08.3 |
HIP 115979 |
12.03 |
| 2026-04-06 12:00 |
23:31:43.99 |
+35:18:46.1 |
HIP 116174 |
7.92 |
| 2026-04-07 00:00 |
23:33:14.76 |
+35:25:20.0 |
HIP 116238 |
7.77 |
| 2026-04-07 12:00 |
23:34:45.22 |
+35:31:50.0 |
HIP 116238 |
19.41 |
| 2026-04-08 00:00 |
23:36:15.36 |
+35:38:16.4 |
HIP 116534 |
13.66 |
| 2026-04-08 12:00 |
23:37:45.18 |
+35:44:38.9 |
HIP 116579 |
5.48 |
| 2026-04-09 00:00 |
23:39:14.68 |
+35:50:57.8 |
HIP 116681 |
7.56 |
| 2026-04-09 12:00 |
23:40:43.86 |
+35:57:13.1 |
HIP 116842 |
3.54 |
| 2026-04-10 00:00 |
23:42:12.72 |
+36:03:24.7 |
HIP 116842 |
15.47 |
| 2026-04-10 12:00 |
23:43:41.27 |
+36:09:32.7 |
HIP 117094 |
12.92 |
| 2026-04-11 00:00 |
23:45:09.49 |
+36:15:37.2 |
HIP 117132 |
6.06 |
| 2026-04-11 12:00 |
23:46:37.40 |
+36:21:38.1 |
HIP 117197 |
11.59 |
| 2026-04-12 00:00 |
23:48:04.98 |
+36:27:35.6 |
HIP 117426 |
12.69 |
| 2026-04-12 12:00 |
23:49:32.24 |
+36:33:29.6 |
HIP 117503 |
8.16 |
| 2026-04-13 00:00 |
23:50:59.19 |
+36:39:20.3 |
HIP 117503 |
20.92 |
| 2026-04-13 12:00 |
23:52:25.81 |
+36:45:07.5 |
HIP 117762 |
13.59 |
| 2026-04-14 00:00 |
23:53:52.11 |
+36:50:51.4 |
HIP 117762 |
12.87 |
| 2026-04-14 12:00 |
23:55:18.09 |
+36:56:32.0 |
HIP 117762 |
28.33 |
| 2026-04-15 00:00 |
23:56:43.74 |
+37:02:09.3 |
HIP 117890 |
40.64 |
| 2026-04-15 12:00 |
23:58:09.08 |
+37:07:43.4 |
HIP 70 |
38.21 |
| 2026-04-16 00:00 |
23:59:34.09 |
+37:13:14.3 |
HIP 71 |
30.44 |