C/2025 V1 (Borisov)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2025 V1 (Borisov) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2025-11-16T13:01:46.663680Z |
| Orbit solution date (soln_date, UTC) | 2026-01-07T15:42:51Z |
| Obs used | 116 |
| NEO | - |
| M1 | 15.200 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2025-11-02T02:35:59.712000Z |
| Discovery magnitude (MPC) | 12.00 G |
| Discovery observatory (MPC) | L51 · MARGO, Nauchnyi |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2025-11-04.0000000 |
| e | 1.00773223 |
| q (au) | 0.462678 |
| a (au) | -59.837579 |
| i (deg) | 112.709493 |
| Ω (om, deg) | 91.873735 |
| ω (w, deg) | 47.568121 |
| M (ma, deg) | -0.026708 |
Magnitude
Scatter + Global Linear
$$ M_a = (15.462 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 15.462 |
| n | 2.000 |
| gf | 0.800 |
| gb | -1.000 |
| k | 0.800 |
| δ90 | 1.000 |
| 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 |
|---|---|---|---|
| 2025-10-29 | 2025-11-03 | +89.0285 | +20.293 |
| 2025-11-03 | 2025-11-08 | -70.7520 | -18.910 |
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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 19:14:59.82 | -24:05:58.8 | HIP 94645 | 8.97 |
| 2026-05-12 12:00 | 19:14:15.87 | -24:11:06.5 | HIP 94645 | 17.63 |
| 2026-05-13 00:00 | 19:13:31.46 | -24:16:14.3 | HIP 94397 | 16.68 |
| 2026-05-13 12:00 | 19:12:46.59 | -24:21:22.0 | HIP 94397 | 7.87 |
| 2026-05-14 00:00 | 19:12:01.27 | -24:26:29.7 | HIP 94397 | 10.44 |
| 2026-05-14 12:00 | 19:11:15.49 | -24:31:37.2 | HIP 94397 | 20.62 |
| 2026-05-15 00:00 | 19:10:29.27 | -24:36:44.5 | HIP 94238 | 26.58 |
| 2026-05-15 12:00 | 19:09:42.60 | -24:41:51.5 | HIP 93993 | 20.15 |
| 2026-05-16 00:00 | 19:08:55.49 | -24:46:58.3 | HIP 93993 | 11.96 |
| 2026-05-16 12:00 | 19:08:07.95 | -24:52:04.7 | HIP 93993 | 12.73 |
| 2026-05-17 00:00 | 19:07:19.98 | -24:57:10.7 | HIP 94045 | 21.09 |
| 2026-05-17 12:00 | 19:06:31.59 | -25:02:16.2 | HIP 93691 | 26.59 |
| 2026-05-18 00:00 | 19:05:42.77 | -25:07:21.2 | HIP 93691 | 14.43 |
| 2026-05-18 12:00 | 19:04:53.55 | -25:12:25.7 | HIP 93691 | 2.26 |
| 2026-05-19 00:00 | 19:04:03.91 | -25:17:29.4 | HIP 93691 | 10.15 |
| 2026-05-19 12:00 | 19:03:13.87 | -25:22:32.5 | HIP 93492 | 21.88 |
| 2026-05-20 00:00 | 19:02:23.43 | -25:27:34.9 | HIP 93492 | 13.73 |
| 2026-05-20 12:00 | 19:01:32.61 | -25:32:36.4 | HIP 93492 | 14.51 |
| 2026-05-21 00:00 | 19:00:41.39 | -25:37:37.1 | HIP 93492 | 23.43 |
| 2026-05-21 12:00 | 18:59:49.80 | -25:42:36.8 | HIP 93303 | 28.96 |
| 2026-05-22 00:00 | 18:58:57.85 | -25:47:35.6 | HIP 93303 | 29.23 |
| 2026-05-22 12:00 | 18:58:05.52 | -25:52:33.3 | HIP 93041 | 27.70 |
| 2026-05-23 00:00 | 18:57:12.84 | -25:57:30.0 | HIP 93041 | 29.60 |
| 2026-05-23 12:00 | 18:56:19.81 | -26:02:25.4 | HIP 92855 | 21.02 |
| 2026-05-24 00:00 | 18:55:26.44 | -26:07:19.7 | HIP 92855 | 10.73 |
| 2026-05-24 12:00 | 18:54:32.73 | -26:12:12.7 | HIP 92855 | 11.18 |
| 2026-05-25 00:00 | 18:53:38.69 | -26:17:04.4 | HIP 92855 | 21.80 |
| 2026-05-25 12:00 | 18:52:44.33 | -26:21:54.7 | HIP 92635 | 17.50 |
| 2026-05-26 00:00 | 18:51:49.67 | -26:26:43.5 | HIP 92635 | 15.04 |
| 2026-05-26 12:00 | 18:50:54.69 | -26:31:30.9 | HIP 92463 | 15.20 |
| 2026-05-27 00:00 | 18:49:59.42 | -26:36:16.7 | HIP 92463 | 13.09 |
| 2026-05-27 12:00 | 18:49:03.86 | -26:41:00.9 | HIP 92463 | 21.55 |
| 2026-05-28 00:00 | 18:48:08.03 | -26:45:43.4 | HIP 92385 | 29.44 |
| 2026-05-28 12:00 | 18:47:11.92 | -26:50:24.2 | HIP 92041 | 22.53 |
| 2026-05-29 00:00 | 18:46:15.55 | -26:55:03.3 | HIP 92041 | 9.18 |
| 2026-05-29 12:00 | 18:45:18.92 | -26:59:40.6 | HIP 92041 | 4.56 |
| 2026-05-30 00:00 | 18:44:22.05 | -27:04:15.9 | HIP 92041 | 17.88 |
| 2026-05-30 12:00 | 18:43:24.94 | -27:08:49.4 | HIP 91682 | 28.06 |
| 2026-05-31 00:00 | 18:42:27.60 | -27:13:20.9 | HIP 91682 | 16.03 |
| 2026-05-31 12:00 | 18:41:30.05 | -27:17:50.4 | HIP 91682 | 9.67 |
| 2026-06-01 00:00 | 18:40:32.28 | -27:22:17.8 | HIP 91682 | 17.27 |
| 2026-06-01 12:00 | 18:39:34.32 | -27:26:43.1 | HIP 91682 | 29.56 |
| 2026-06-02 00:00 | 18:38:36.17 | -27:31:06.3 | HIP 91268 | 25.12 |