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) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 19:26:41.85 | -12:04:52.1 | HIP 95722 | 22.42 |
| 2026-02-03 12:00 | 19:27:07.01 | -12:08:13.5 | HIP 95722 | 15.95 |
| 2026-02-04 00:00 | 19:27:31.96 | -12:11:33.5 | HIP 95722 | 10.26 |
| 2026-02-04 12:00 | 19:27:56.69 | -12:14:52.2 | HIP 95722 | 7.27 |
| 2026-02-05 00:00 | 19:28:21.21 | -12:18:09.7 | HIP 95722 | 9.73 |
| 2026-02-05 12:00 | 19:28:45.52 | -12:21:26.0 | HIP 95722 | 15.12 |
| 2026-02-06 00:00 | 19:29:09.61 | -12:24:41.1 | HIP 95847 | 15.70 |
| 2026-02-06 12:00 | 19:29:33.50 | -12:27:55.0 | HIP 95883 | 9.81 |
| 2026-02-07 00:00 | 19:29:57.16 | -12:31:07.8 | HIP 95883 | 3.88 |
| 2026-02-07 12:00 | 19:30:20.62 | -12:34:19.5 | HIP 95883 | 4.56 |
| 2026-02-08 00:00 | 19:30:43.86 | -12:37:30.1 | HIP 95883 | 10.55 |
| 2026-02-08 12:00 | 19:31:06.89 | -12:40:39.7 | HIP 95883 | 16.86 |
| 2026-02-09 00:00 | 19:31:29.70 | -12:43:48.3 | HIP 95883 | 23.19 |
| 2026-02-09 12:00 | 19:31:52.30 | -12:46:55.9 | HIP 95883 | 29.49 |
| 2026-02-10 00:00 | 19:32:14.68 | -12:50:02.6 | HIP 96265 | 32.51 |
| 2026-02-10 12:00 | 19:32:36.85 | -12:53:08.4 | HIP 96265 | 26.74 |
| 2026-02-11 00:00 | 19:32:58.80 | -12:56:13.3 | HIP 96265 | 21.29 |
| 2026-02-11 12:00 | 19:33:20.53 | -12:59:17.3 | HIP 96265 | 16.40 |
| 2026-02-12 00:00 | 19:33:42.05 | -13:02:20.5 | HIP 96265 | 12.69 |
| 2026-02-12 12:00 | 19:34:03.34 | -13:05:22.9 | HIP 96265 | 11.26 |
| 2026-02-13 00:00 | 19:34:24.42 | -13:08:24.6 | HIP 96265 | 12.83 |
| 2026-02-13 12:00 | 19:34:45.28 | -13:11:25.5 | HIP 96265 | 16.51 |
| 2026-02-14 00:00 | 19:35:05.91 | -13:14:25.7 | HIP 96265 | 21.19 |
| 2026-02-14 12:00 | 19:35:26.33 | -13:17:25.3 | HIP 96495 | 24.38 |
| 2026-02-15 00:00 | 19:35:46.52 | -13:20:24.2 | HIP 96495 | 20.97 |
| 2026-02-15 12:00 | 19:36:06.49 | -13:23:22.4 | HIP 96495 | 18.78 |
| 2026-02-16 00:00 | 19:36:26.23 | -13:26:20.1 | HIP 96495 | 18.20 |
| 2026-02-16 12:00 | 19:36:45.75 | -13:29:17.2 | HIP 96495 | 19.33 |
| 2026-02-17 00:00 | 19:37:05.04 | -13:32:13.8 | HIP 96495 | 21.86 |
| 2026-02-17 12:00 | 19:37:24.10 | -13:35:09.9 | HIP 96558 | 23.00 |
| 2026-02-18 00:00 | 19:37:42.94 | -13:38:05.5 | HIP 96558 | 19.34 |
| 2026-02-18 12:00 | 19:38:01.54 | -13:41:00.7 | HIP 96657 | 15.69 |
| 2026-02-19 00:00 | 19:38:19.91 | -13:43:55.4 | HIP 96657 | 11.82 |
| 2026-02-19 12:00 | 19:38:38.05 | -13:46:49.8 | HIP 96657 | 9.51 |
| 2026-02-20 00:00 | 19:38:55.96 | -13:49:43.8 | HIP 96657 | 9.86 |
| 2026-02-20 12:00 | 19:39:13.63 | -13:52:37.4 | HIP 96657 | 12.58 |
| 2026-02-21 00:00 | 19:39:31.07 | -13:55:30.8 | HIP 96753 | 10.92 |
| 2026-02-21 12:00 | 19:39:48.27 | -13:58:23.8 | HIP 96753 | 5.91 |
| 2026-02-22 00:00 | 19:40:05.23 | -14:01:16.6 | HIP 96753 | 1.40 |
| 2026-02-22 12:00 | 19:40:21.95 | -14:04:09.2 | HIP 96753 | 4.35 |
| 2026-02-23 00:00 | 19:40:38.43 | -14:07:01.6 | HIP 96753 | 9.19 |
| 2026-02-23 12:00 | 19:40:54.68 | -14:09:53.7 | HIP 96753 | 14.03 |
| 2026-02-24 00:00 | 19:41:10.67 | -14:12:45.8 | HIP 96753 | 18.83 |