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) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 17:05:38.99 | -31:17:14.5 | HIP 83581 | 10.46 |
| 2026-07-29 12:00 | 17:05:12.25 | -31:17:32.3 | HIP 83581 | 5.90 |
| 2026-07-30 00:00 | 17:04:45.95 | -31:17:49.5 | HIP 83569 | 3.94 |
| 2026-07-30 12:00 | 17:04:20.09 | -31:18:06.1 | HIP 83569 | 6.69 |
| 2026-07-31 00:00 | 17:03:54.68 | -31:18:22.3 | HIP 83569 | 11.53 |
| 2026-07-31 12:00 | 17:03:29.72 | -31:18:37.9 | HIP 83569 | 16.65 |
| 2026-08-01 00:00 | 17:03:05.19 | -31:18:53.0 | HIP 83448 | 18.20 |
| 2026-08-01 12:00 | 17:02:41.11 | -31:19:07.6 | HIP 83448 | 19.41 |
| 2026-08-02 00:00 | 17:02:17.46 | -31:19:21.8 | HIP 83448 | 21.75 |
| 2026-08-02 12:00 | 17:01:54.24 | -31:19:35.6 | HIP 83448 | 24.84 |
| 2026-08-03 00:00 | 17:01:31.46 | -31:19:49.0 | HIP 83182 | 21.57 |
| 2026-08-03 12:00 | 17:01:09.11 | -31:20:01.9 | HIP 83182 | 17.39 |
| 2026-08-04 00:00 | 17:00:47.19 | -31:20:14.6 | HIP 83182 | 13.67 |
| 2026-08-04 12:00 | 17:00:25.69 | -31:20:26.9 | HIP 83182 | 10.79 |
| 2026-08-05 00:00 | 17:00:04.62 | -31:20:38.8 | HIP 83182 | 9.38 |
| 2026-08-05 12:00 | 16:59:43.98 | -31:20:50.5 | HIP 83182 | 9.98 |
| 2026-08-06 00:00 | 16:59:23.75 | -31:21:01.9 | HIP 83182 | 12.19 |
| 2026-08-06 12:00 | 16:59:03.94 | -31:21:13.0 | HIP 83182 | 15.26 |
| 2026-08-07 00:00 | 16:58:44.54 | -31:21:23.9 | HIP 83182 | 18.71 |
| 2026-08-07 12:00 | 16:58:25.57 | -31:21:34.6 | HIP 83182 | 22.31 |
| 2026-08-08 00:00 | 16:58:07.00 | -31:21:45.1 | HIP 82888 | 22.88 |
| 2026-08-08 12:00 | 16:57:48.84 | -31:21:55.4 | HIP 82888 | 19.00 |
| 2026-08-09 00:00 | 16:57:31.09 | -31:22:05.5 | HIP 82888 | 15.21 |
| 2026-08-09 12:00 | 16:57:13.74 | -31:22:15.4 | HIP 82888 | 11.50 |
| 2026-08-10 00:00 | 16:56:56.80 | -31:22:25.3 | HIP 82888 | 7.88 |
| 2026-08-10 12:00 | 16:56:40.26 | -31:22:35.0 | HIP 82888 | 4.35 |
| 2026-08-11 00:00 | 16:56:24.11 | -31:22:44.6 | HIP 82888 | 0.90 |
| 2026-08-11 12:00 | 16:56:08.36 | -31:22:54.1 | HIP 82888 | 2.47 |
| 2026-08-12 00:00 | 16:55:53.01 | -31:23:03.5 | HIP 82848 | 5.13 |
| 2026-08-12 12:00 | 16:55:38.04 | -31:23:12.9 | HIP 82848 | 5.82 |
| 2026-08-13 00:00 | 16:55:23.47 | -31:23:22.2 | HIP 82792 | 3.25 |
| 2026-08-13 12:00 | 16:55:09.28 | -31:23:31.5 | HIP 82792 | 0.64 |
| 2026-08-14 00:00 | 16:54:55.47 | -31:23:40.8 | HIP 82792 | 2.86 |
| 2026-08-14 12:00 | 16:54:42.05 | -31:23:50.1 | HIP 82732 | 3.94 |
| 2026-08-15 00:00 | 16:54:29.00 | -31:23:59.4 | HIP 82732 | 4.23 |
| 2026-08-15 12:00 | 16:54:16.33 | -31:24:08.7 | HIP 82732 | 5.92 |
| 2026-08-16 00:00 | 16:54:04.03 | -31:24:18.0 | HIP 82732 | 8.11 |
| 2026-08-16 12:00 | 16:53:52.09 | -31:24:27.4 | HIP 82732 | 10.44 |
| 2026-08-17 00:00 | 16:53:40.53 | -31:24:36.9 | HIP 82732 | 12.78 |
| 2026-08-17 12:00 | 16:53:29.33 | -31:24:46.4 | HIP 82732 | 15.08 |
| 2026-08-18 00:00 | 16:53:18.49 | -31:24:55.9 | HIP 82732 | 17.34 |
| 2026-08-18 12:00 | 16:53:08.01 | -31:25:05.6 | HIP 82732 | 19.54 |
| 2026-08-19 00:00 | 16:52:57.89 | -31:25:15.4 | HIP 82732 | 21.67 |