C/2026 B2 (Sun-Gao)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2026 B2 (Sun-Gao) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2026-01-10T02:51:05.140800Z |
| Orbit solution date (soln_date, UTC) | 2026-08-25T08:42:11Z |
| Obs used | 194 |
| NEO | - |
| M1 | 13.500 |
| K1 | 8.750 |
| 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) | 2026-02-14.0000000 |
| e | 0.99759879 |
| q (au) | 1.284257 |
| a (au) | 534.838325 |
| i (deg) | 59.578698 |
| Ω (om, deg) | 234.638526 |
| ω (w, deg) | 47.299433 |
| M (ma, deg) | 0.002779 |
Magnitude
Scatter + Global Linear
$$ M_a = (12.639 + 3.129\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 12.639 |
| n | 3.129 |
| gf | 0.999 |
| gb | -1.000 |
| 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 | 2026-02-25 | -44.5327 | +5.176 |
| 2026-02-25 | 2026-08-24 | +8.1966 | -2.535 |
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) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 02:57:20.88 | +45:31:45.8 | HIP 13734 | 24.97 |
| 2026-09-20 12:00 | 02:56:56.39 | +45:29:43.3 | HIP 13734 | 22.41 |
| 2026-09-21 00:00 | 02:56:31.56 | +45:27:37.9 | HIP 13734 | 20.61 |
| 2026-09-21 12:00 | 02:56:06.41 | +45:25:29.5 | HIP 13734 | 19.84 |
| 2026-09-22 00:00 | 02:55:40.93 | +45:23:18.1 | HIP 13734 | 20.26 |
| 2026-09-22 12:00 | 02:55:15.14 | +45:21:03.8 | HIP 13734 | 21.86 |
| 2026-09-23 00:00 | 02:54:49.03 | +45:18:46.5 | HIP 13734 | 24.45 |
| 2026-09-23 12:00 | 02:54:22.61 | +45:16:26.1 | HIP 13734 | 27.80 |
| 2026-09-24 00:00 | 02:53:55.89 | +45:14:02.7 | HIP 13343 | 25.62 |
| 2026-09-24 12:00 | 02:53:28.86 | +45:11:36.2 | HIP 13343 | 20.29 |
| 2026-09-25 00:00 | 02:53:01.55 | +45:09:06.7 | HIP 13343 | 14.89 |
| 2026-09-25 12:00 | 02:52:33.94 | +45:06:34.1 | HIP 13343 | 9.44 |
| 2026-09-26 00:00 | 02:52:06.06 | +45:03:58.3 | HIP 13343 | 4.05 |
| 2026-09-26 12:00 | 02:51:37.89 | +45:01:19.4 | HIP 13343 | 2.45 |
| 2026-09-27 00:00 | 02:51:09.45 | +44:58:37.4 | HIP 13343 | 7.76 |
| 2026-09-27 12:00 | 02:50:40.74 | +44:55:52.3 | HIP 13360 | 12.96 |
| 2026-09-28 00:00 | 02:50:11.77 | +44:53:03.9 | HIP 13360 | 17.92 |
| 2026-09-28 12:00 | 02:49:42.55 | +44:50:12.4 | HIP 13360 | 23.35 |
| 2026-09-29 00:00 | 02:49:13.07 | +44:47:17.7 | HIP 13360 | 29.03 |
| 2026-09-29 12:00 | 02:48:43.35 | +44:44:19.8 | HIP 13036 | 30.81 |
| 2026-09-30 00:00 | 02:48:13.38 | +44:41:18.6 | HIP 13036 | 26.09 |
| 2026-09-30 12:00 | 02:47:43.18 | +44:38:14.2 | HIP 13036 | 22.01 |
| 2026-10-01 00:00 | 02:47:12.76 | +44:35:06.6 | HIP 13036 | 19.06 |
| 2026-10-01 12:00 | 02:46:42.11 | +44:31:55.7 | HIP 13036 | 17.89 |
| 2026-10-02 00:00 | 02:46:11.25 | +44:28:41.6 | HIP 13036 | 18.89 |
| 2026-10-02 12:00 | 02:45:40.17 | +44:25:24.2 | HIP 12768 | 18.60 |
| 2026-10-03 00:00 | 02:45:08.89 | +44:22:03.5 | HIP 12768 | 12.16 |
| 2026-10-03 12:00 | 02:44:37.41 | +44:18:39.5 | HIP 12768 | 5.83 |
| 2026-10-04 00:00 | 02:44:05.75 | +44:15:12.3 | HIP 12768 | 2.62 |
| 2026-10-04 12:00 | 02:43:33.89 | +44:11:41.7 | HIP 12768 | 8.30 |
| 2026-10-05 00:00 | 02:43:01.86 | +44:08:07.8 | HIP 12768 | 14.92 |
| 2026-10-05 12:00 | 02:42:29.65 | +44:04:30.7 | HIP 12544 | 16.20 |
| 2026-10-06 00:00 | 02:41:57.29 | +44:00:50.2 | HIP 12478 | 15.17 |
| 2026-10-06 12:00 | 02:41:24.76 | +43:57:06.5 | HIP 12478 | 12.00 |
| 2026-10-07 00:00 | 02:40:52.08 | +43:53:19.4 | HIP 12478 | 12.45 |
| 2026-10-07 12:00 | 02:40:19.26 | +43:49:29.0 | HIP 12478 | 16.30 |
| 2026-10-08 00:00 | 02:39:46.30 | +43:45:35.4 | HIP 12478 | 21.87 |
| 2026-10-08 12:00 | 02:39:13.21 | +43:41:38.4 | HIP 12339 | 27.70 |
| 2026-10-09 00:00 | 02:38:39.99 | +43:37:38.2 | HIP 12339 | 23.63 |
| 2026-10-09 12:00 | 02:38:06.67 | +43:33:34.6 | HIP 12339 | 21.26 |
| 2026-10-10 00:00 | 02:37:33.23 | +43:29:27.9 | HIP 12082 | 20.90 |
| 2026-10-10 12:00 | 02:36:59.70 | +43:25:17.8 | HIP 12082 | 17.42 |
| 2026-10-11 00:00 | 02:36:26.07 | +43:21:04.5 | HIP 12082 | 16.73 |