C/2020 V2 (ZTF)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2020 V2 (ZTF) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2023-05-08T13:21:29.376000Z |
| Orbit solution date (soln_date, UTC) | 2025-09-30T13:39:21Z |
| Obs used | 5767 |
| NEO | - |
| M1 | 8.700 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2020-11-02T12:42:20.160000Z |
| Discovery magnitude (MPC) | 19.04 r |
| Discovery observatory (MPC) | I41 · Palomar Mountain–ZTF |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2022-10-07.0000000 |
| e | 1.00089953 |
| q (au) | 2.227960 |
| a (au) | -2476.803384 |
| i (deg) | 131.611042 |
| Ω (om, deg) | 212.371235 |
| ω (w, deg) | 162.424317 |
| M (ma, deg) | -0.001708 |
Magnitude
Scatter + Global Linear
$$ M_a = (8.951 + 2.985\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 8.951 |
| n | 2.985 |
| gf | 1.000 |
| gb | -0.726 |
| k | 0.800 |
| δ90 | 10.000 |
| 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 |
|---|---|---|---|
| 2020-04-18 | 2022-11-29 | +2.8905 | -2.125 |
| 2022-11-29 | 2023-04-18 | +1.1777 | -1.001 |
| 2023-06-12 | 2023-08-25 | +25.9574 | -10.877 |
| 2023-08-25 | 2024-05-20 | -2.9823 | +1.312 |
| 2024-05-20 | 2025-10-26 | +0.5312 | -0.877 |
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) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 17:45:26.49 | -68:54:54.6 | HIP 86741 | 10.77 |
| 2026-09-20 12:00 | 17:45:22.97 | -68:52:43.5 | HIP 86741 | 10.96 |
| 2026-09-21 00:00 | 17:45:19.72 | -68:50:32.6 | HIP 86741 | 11.59 |
| 2026-09-21 12:00 | 17:45:16.75 | -68:48:22.0 | HIP 86930 | 9.83 |
| 2026-09-22 00:00 | 17:45:14.05 | -68:46:11.7 | HIP 86930 | 7.83 |
| 2026-09-22 12:00 | 17:45:11.61 | -68:44:01.7 | HIP 86930 | 5.96 |
| 2026-09-23 00:00 | 17:45:09.45 | -68:41:51.9 | HIP 86930 | 4.36 |
| 2026-09-23 12:00 | 17:45:07.55 | -68:39:42.5 | HIP 86930 | 3.45 |
| 2026-09-24 00:00 | 17:45:05.91 | -68:37:33.4 | HIP 86930 | 3.73 |
| 2026-09-24 12:00 | 17:45:04.53 | -68:35:24.6 | HIP 86930 | 5.00 |
| 2026-09-25 00:00 | 17:45:03.41 | -68:33:16.1 | HIP 86930 | 6.72 |
| 2026-09-25 12:00 | 17:45:02.55 | -68:31:08.0 | HIP 86930 | 8.61 |
| 2026-09-26 00:00 | 17:45:01.94 | -68:29:00.2 | HIP 86930 | 10.59 |
| 2026-09-26 12:00 | 17:45:01.58 | -68:26:52.8 | HIP 86930 | 12.60 |
| 2026-09-27 00:00 | 17:45:01.48 | -68:24:45.7 | HIP 86930 | 14.63 |
| 2026-09-27 12:00 | 17:45:01.62 | -68:22:39.0 | HIP 86930 | 16.67 |
| 2026-09-28 00:00 | 17:45:02.01 | -68:20:32.6 | HIP 86930 | 18.72 |
| 2026-09-28 12:00 | 17:45:02.64 | -68:18:26.7 | HIP 86930 | 20.77 |
| 2026-09-29 00:00 | 17:45:03.52 | -68:16:21.1 | HIP 86930 | 22.82 |
| 2026-09-29 12:00 | 17:45:04.64 | -68:14:15.9 | HIP 86930 | 24.86 |
| 2026-09-30 00:00 | 17:45:05.99 | -68:12:11.1 | HIP 86930 | 26.90 |
| 2026-09-30 12:00 | 17:45:07.59 | -68:10:06.7 | HIP 86930 | 28.94 |
| 2026-10-01 00:00 | 17:45:09.41 | -68:08:02.7 | HIP 86510 | 29.96 |
| 2026-10-01 12:00 | 17:45:11.47 | -68:05:59.1 | HIP 86510 | 29.04 |
| 2026-10-02 00:00 | 17:45:13.77 | -68:03:56.0 | HIP 87142 | 28.04 |
| 2026-10-02 12:00 | 17:45:16.29 | -68:01:53.2 | HIP 87142 | 26.30 |
| 2026-10-03 00:00 | 17:45:19.04 | -67:59:50.9 | HIP 87142 | 24.61 |
| 2026-10-03 12:00 | 17:45:22.02 | -67:57:49.1 | HIP 87142 | 22.97 |
| 2026-10-04 00:00 | 17:45:25.22 | -67:55:47.7 | HIP 87142 | 21.38 |
| 2026-10-04 12:00 | 17:45:28.64 | -67:53:46.7 | HIP 87142 | 19.86 |
| 2026-10-05 00:00 | 17:45:32.29 | -67:51:46.2 | HIP 87142 | 18.43 |
| 2026-10-05 12:00 | 17:45:36.15 | -67:49:46.2 | HIP 87142 | 17.11 |
| 2026-10-06 00:00 | 17:45:40.23 | -67:47:46.6 | HIP 87142 | 15.93 |
| 2026-10-06 12:00 | 17:45:44.53 | -67:45:47.5 | HIP 87142 | 14.91 |
| 2026-10-07 00:00 | 17:45:49.04 | -67:43:48.9 | HIP 87142 | 14.08 |
| 2026-10-07 12:00 | 17:45:53.76 | -67:41:50.7 | HIP 87142 | 13.49 |
| 2026-10-08 00:00 | 17:45:58.70 | -67:39:53.1 | HIP 87142 | 13.17 |
| 2026-10-08 12:00 | 17:46:03.84 | -67:37:55.9 | HIP 87142 | 13.12 |
| 2026-10-09 00:00 | 17:46:09.19 | -67:35:59.3 | HIP 87142 | 13.36 |
| 2026-10-09 12:00 | 17:46:14.74 | -67:34:03.2 | HIP 87142 | 13.87 |
| 2026-10-10 00:00 | 17:46:20.50 | -67:32:07.5 | HIP 87126 | 13.52 |
| 2026-10-10 12:00 | 17:46:26.45 | -67:30:12.4 | HIP 87126 | 11.85 |
| 2026-10-11 00:00 | 17:46:32.61 | -67:28:17.9 | HIP 87126 | 10.29 |