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) |
|---|---|---|---|---|
| 2026-06-01 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 |
| 2026-06-02 12:00 | 18:37:37.83 | -27:35:27.3 | HIP 91268 | 12.10 |
| 2026-06-03 00:00 | 18:36:39.32 | -27:39:46.0 | HIP 91268 | 5.87 |
| 2026-06-03 12:00 | 18:35:40.66 | -27:44:02.4 | HIP 91075 | 17.21 |
| 2026-06-04 00:00 | 18:34:41.84 | -27:48:16.5 | HIP 91075 | 14.33 |
| 2026-06-04 12:00 | 18:33:42.87 | -27:52:28.2 | HIP 91085 | 17.91 |
| 2026-06-05 00:00 | 18:32:43.78 | -27:56:37.5 | HIP 90739 | 24.32 |
| 2026-06-05 12:00 | 18:31:44.57 | -28:00:44.4 | HIP 90739 | 11.81 |
| 2026-06-06 00:00 | 18:30:45.24 | -28:04:48.8 | HIP 90739 | 7.93 |
| 2026-06-06 12:00 | 18:29:45.81 | -28:08:50.6 | HIP 90611 | 11.79 |
| 2026-06-07 00:00 | 18:28:46.29 | -28:12:49.9 | HIP 90504 | 13.81 |
| 2026-06-07 12:00 | 18:27:46.69 | -28:16:46.6 | HIP 90504 | 7.48 |
| 2026-06-08 00:00 | 18:26:47.02 | -28:20:40.7 | HIP 90504 | 17.24 |
| 2026-06-08 12:00 | 18:25:47.29 | -28:24:32.2 | HIP 90504 | 30.22 |
| 2026-06-09 00:00 | 18:24:47.51 | -28:28:20.9 | HIP 90100 | 20.73 |
| 2026-06-09 12:00 | 18:23:47.69 | -28:32:07.0 | HIP 90100 | 10.36 |
| 2026-06-10 00:00 | 18:22:47.84 | -28:35:50.3 | HIP 90100 | 12.58 |
| 2026-06-10 12:00 | 18:21:47.97 | -28:39:30.9 | HIP 89929 | 11.19 |
| 2026-06-11 00:00 | 18:20:48.10 | -28:43:08.6 | HIP 89929 | 2.43 |
| 2026-06-11 12:00 | 18:19:48.23 | -28:46:43.6 | HIP 89786 | 14.25 |
| 2026-06-12 00:00 | 18:18:48.38 | -28:50:15.8 | HIP 89786 | 12.49 |
| 2026-06-12 12:00 | 18:17:48.55 | -28:53:45.1 | HIP 89622 | 15.58 |
| 2026-06-13 00:00 | 18:16:48.76 | -28:57:11.5 | HIP 89622 | 19.66 |
| 2026-06-13 12:00 | 18:15:49.02 | -29:00:35.1 | HIP 89392 | 19.50 |
| 2026-06-14 00:00 | 18:14:49.33 | -29:03:55.7 | HIP 89392 | 14.05 |
| 2026-06-14 12:00 | 18:13:49.71 | -29:07:13.5 | HIP 89392 | 19.39 |
| 2026-06-15 00:00 | 18:12:50.18 | -29:10:28.4 | HIP 89178 | 19.94 |
| 2026-06-15 12:00 | 18:11:50.73 | -29:13:40.3 | HIP 89178 | 19.65 |
| 2026-06-16 00:00 | 18:10:51.39 | -29:16:49.3 | HIP 89116 | 22.20 |
| 2026-06-16 12:00 | 18:09:52.16 | -29:19:55.4 | HIP 88955 | 19.96 |
| 2026-06-17 00:00 | 18:08:53.05 | -29:22:58.5 | HIP 88783 | 19.70 |
| 2026-06-17 12:00 | 18:07:54.07 | -29:25:58.6 | HIP 88783 | 6.58 |
| 2026-06-18 00:00 | 18:06:55.24 | -29:28:55.9 | HIP 88783 | 6.76 |
| 2026-06-18 12:00 | 18:05:56.56 | -29:31:50.1 | HIP 88567 | 12.40 |
| 2026-06-19 00:00 | 18:04:58.05 | -29:34:41.5 | HIP 88567 | 0.70 |
| 2026-06-19 12:00 | 18:03:59.71 | -29:37:29.8 | HIP 88447 | 7.02 |
| 2026-06-20 00:00 | 18:03:01.56 | -29:40:15.3 | HIP 88447 | 6.64 |
| 2026-06-20 12:00 | 18:02:03.60 | -29:42:57.8 | HIP 88339 | 5.87 |
| 2026-06-21 00:00 | 18:01:05.84 | -29:45:37.4 | HIP 88339 | 18.49 |
| 2026-06-21 12:00 | 18:00:08.30 | -29:48:14.0 | HIP 88198 | 25.66 |
| 2026-06-22 00:00 | 17:59:10.97 | -29:50:47.8 | HIP 88033 | 19.80 |