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) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 19:48:52.11 | -17:14:13.9 | HIP 97419 | 19.09 |
| 2026-03-26 12:00 | 19:48:50.27 | -17:17:38.0 | HIP 97419 | 16.32 |
| 2026-03-27 00:00 | 19:48:48.08 | -17:21:03.1 | HIP 97419 | 13.77 |
| 2026-03-27 12:00 | 19:48:45.52 | -17:24:29.4 | HIP 97419 | 11.60 |
| 2026-03-28 00:00 | 19:48:42.61 | -17:27:56.9 | HIP 97419 | 10.11 |
| 2026-03-28 12:00 | 19:48:39.33 | -17:31:25.5 | HIP 97419 | 9.66 |
| 2026-03-29 00:00 | 19:48:35.69 | -17:34:55.3 | HIP 97419 | 10.41 |
| 2026-03-29 12:00 | 19:48:31.68 | -17:38:26.2 | HIP 97419 | 12.19 |
| 2026-03-30 00:00 | 19:48:27.29 | -17:41:58.4 | HIP 97419 | 14.66 |
| 2026-03-30 12:00 | 19:48:22.54 | -17:45:31.8 | HIP 97419 | 17.55 |
| 2026-03-31 00:00 | 19:48:17.41 | -17:49:06.4 | HIP 97419 | 20.71 |
| 2026-03-31 12:00 | 19:48:11.90 | -17:52:42.2 | HIP 97419 | 24.07 |
| 2026-04-01 00:00 | 19:48:06.01 | -17:56:19.3 | HIP 97296 | 26.98 |
| 2026-04-01 12:00 | 19:47:59.74 | -17:59:57.7 | HIP 97296 | 24.07 |
| 2026-04-02 00:00 | 19:47:53.08 | -18:03:37.3 | HIP 97409 | 20.64 |
| 2026-04-02 12:00 | 19:47:46.04 | -18:07:18.2 | HIP 97409 | 17.05 |
| 2026-04-03 00:00 | 19:47:38.61 | -18:11:00.4 | HIP 97409 | 13.72 |
| 2026-04-03 12:00 | 19:47:30.79 | -18:14:43.9 | HIP 97409 | 10.95 |
| 2026-04-04 00:00 | 19:47:22.57 | -18:18:28.7 | HIP 97409 | 9.35 |
| 2026-04-04 12:00 | 19:47:13.96 | -18:22:14.9 | HIP 97409 | 9.61 |
| 2026-04-05 00:00 | 19:47:04.94 | -18:26:02.3 | HIP 97409 | 11.67 |
| 2026-04-05 12:00 | 19:46:55.53 | -18:29:51.1 | HIP 97409 | 14.86 |
| 2026-04-06 00:00 | 19:46:45.70 | -18:33:41.3 | HIP 97358 | 13.50 |
| 2026-04-06 12:00 | 19:46:35.48 | -18:37:32.8 | HIP 97358 | 12.43 |
| 2026-04-07 00:00 | 19:46:24.84 | -18:41:25.7 | HIP 97358 | 13.06 |
| 2026-04-07 12:00 | 19:46:13.79 | -18:45:19.9 | HIP 97358 | 15.25 |
| 2026-04-08 00:00 | 19:46:02.32 | -18:49:15.5 | HIP 97358 | 18.50 |
| 2026-04-08 12:00 | 19:45:50.44 | -18:53:12.5 | HIP 97358 | 22.40 |
| 2026-04-09 00:00 | 19:45:38.13 | -18:57:10.9 | HIP 97358 | 26.71 |
| 2026-04-09 12:00 | 19:45:25.40 | -19:01:10.7 | HIP 97358 | 31.30 |
| 2026-04-10 00:00 | 19:45:12.25 | -19:05:11.9 | HIP 97031 | 28.39 |
| 2026-04-10 12:00 | 19:44:58.67 | -19:09:14.5 | HIP 97031 | 25.26 |
| 2026-04-11 00:00 | 19:44:44.65 | -19:13:18.5 | HIP 97031 | 22.79 |
| 2026-04-11 12:00 | 19:44:30.21 | -19:17:23.9 | HIP 97031 | 21.27 |
| 2026-04-12 00:00 | 19:44:15.32 | -19:21:30.8 | HIP 97031 | 20.98 |
| 2026-04-12 12:00 | 19:44:00.00 | -19:25:39.1 | HIP 97031 | 22.02 |
| 2026-04-13 00:00 | 19:43:44.24 | -19:29:48.8 | HIP 97031 | 24.29 |
| 2026-04-13 12:00 | 19:43:28.03 | -19:33:59.9 | HIP 97031 | 27.52 |
| 2026-04-14 00:00 | 19:43:11.38 | -19:38:12.4 | HIP 97031 | 31.48 |
| 2026-04-14 12:00 | 19:42:54.27 | -19:42:26.4 | HIP 96983 | 29.35 |
| 2026-04-15 00:00 | 19:42:36.72 | -19:46:41.8 | HIP 96873 | 24.41 |
| 2026-04-15 12:00 | 19:42:18.71 | -19:50:58.6 | HIP 96873 | 18.41 |
| 2026-04-16 00:00 | 19:42:00.24 | -19:55:16.9 | HIP 96873 | 12.34 |