C/2020 F3 (NEOWISE)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2020 F3 (NEOWISE) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2020-07-03T16:17:36.787200Z |
| Orbit solution date (soln_date, UTC) | 2024-07-30T14:57:24Z |
| Obs used | 1315 |
| NEO | - |
| M1 | 12.100 |
| K1 | 12.250 |
| PC | - |
| Discovery observation (MPC, UTC) | 2020-03-27T17:07:28.128000Z |
| Discovery magnitude (MPC) | 17.00 R |
| Discovery observatory (MPC) | C51 · WISE |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2020-07-06.0000000 |
| e | 0.99917803 |
| q (au) | 0.294651 |
| a (au) | 358.467957 |
| i (deg) | 128.937503 |
| Ω (om, deg) | 61.010428 |
| ω (w, deg) | 37.278658 |
| M (ma, deg) | 0.000337 |
Magnitude
Scatter + Global Linear
$$ M_a = (8.789 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 8.789 |
| n | 6.000 |
| gf | 1.000 |
| gb | -0.500 |
| k | 1.000 |
| 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 |
|---|---|---|---|
| 2020-03-27 | 2020-04-22 | +24.5852 | -5.637 |
| 2020-04-22 | 2020-05-07 | +7.8138 | -2.290 |
| 2020-05-07 | 2020-07-03 | +0.3032 | -1.727 |
| 2020-07-04 | 2020-07-17 | +2.2806 | +0.953 |
| 2020-07-17 | 2023-04-14 | -6.6621 | -1.075 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 14:47:19.77 | -34:10:47.2 | HIP 72484 | 24.44 |
| 2026-02-03 12:00 | 14:47:19.42 | -34:11:21.5 | HIP 72484 | 24.58 |
| 2026-02-04 00:00 | 14:47:18.99 | -34:11:55.5 | HIP 72484 | 24.75 |
| 2026-02-04 12:00 | 14:47:18.50 | -34:12:29.3 | HIP 72484 | 24.95 |
| 2026-02-05 00:00 | 14:47:17.93 | -34:13:02.9 | HIP 72484 | 25.17 |
| 2026-02-05 12:00 | 14:47:17.30 | -34:13:36.2 | HIP 72484 | 25.41 |
| 2026-02-06 00:00 | 14:47:16.60 | -34:14:09.3 | HIP 72484 | 25.68 |
| 2026-02-06 12:00 | 14:47:15.82 | -34:14:42.1 | HIP 72484 | 25.97 |
| 2026-02-07 00:00 | 14:47:14.98 | -34:15:14.7 | HIP 72484 | 26.29 |
| 2026-02-07 12:00 | 14:47:14.06 | -34:15:47.1 | HIP 72484 | 26.62 |
| 2026-02-08 00:00 | 14:47:13.08 | -34:16:19.2 | HIP 72484 | 26.97 |
| 2026-02-08 12:00 | 14:47:12.03 | -34:16:51.0 | HIP 72484 | 27.35 |
| 2026-02-09 00:00 | 14:47:10.90 | -34:17:22.6 | HIP 72350 | 27.33 |
| 2026-02-09 12:00 | 14:47:09.71 | -34:17:53.9 | HIP 72350 | 26.88 |
| 2026-02-10 00:00 | 14:47:08.44 | -34:18:24.9 | HIP 72350 | 26.44 |
| 2026-02-10 12:00 | 14:47:07.10 | -34:18:55.7 | HIP 72350 | 26.01 |
| 2026-02-11 00:00 | 14:47:05.70 | -34:19:26.2 | HIP 72350 | 25.60 |
| 2026-02-11 12:00 | 14:47:04.22 | -34:19:56.5 | HIP 72350 | 25.21 |
| 2026-02-12 00:00 | 14:47:02.67 | -34:20:26.4 | HIP 72350 | 24.83 |
| 2026-02-12 12:00 | 14:47:01.06 | -34:20:56.1 | HIP 72350 | 24.47 |
| 2026-02-13 00:00 | 14:46:59.37 | -34:21:25.5 | HIP 72350 | 24.13 |
| 2026-02-13 12:00 | 14:46:57.61 | -34:21:54.7 | HIP 72350 | 23.81 |
| 2026-02-14 00:00 | 14:46:55.78 | -34:22:23.5 | HIP 72350 | 23.51 |
| 2026-02-14 12:00 | 14:46:53.88 | -34:22:52.1 | HIP 72350 | 23.23 |
| 2026-02-15 00:00 | 14:46:51.91 | -34:23:20.3 | HIP 72350 | 22.97 |
| 2026-02-15 12:00 | 14:46:49.87 | -34:23:48.3 | HIP 72350 | 22.75 |
| 2026-02-16 00:00 | 14:46:47.76 | -34:24:16.0 | HIP 72350 | 22.54 |
| 2026-02-16 12:00 | 14:46:45.58 | -34:24:43.3 | HIP 72350 | 22.37 |
| 2026-02-17 00:00 | 14:46:43.33 | -34:25:10.4 | HIP 72099 | 22.07 |
| 2026-02-17 12:00 | 14:46:41.01 | -34:25:37.2 | HIP 72099 | 21.65 |
| 2026-02-18 00:00 | 14:46:38.62 | -34:26:03.6 | HIP 72099 | 21.22 |
| 2026-02-18 12:00 | 14:46:36.16 | -34:26:29.8 | HIP 72099 | 20.79 |
| 2026-02-19 00:00 | 14:46:33.62 | -34:26:55.6 | HIP 72099 | 20.35 |
| 2026-02-19 12:00 | 14:46:31.02 | -34:27:21.2 | HIP 72099 | 19.92 |
| 2026-02-20 00:00 | 14:46:28.35 | -34:27:46.4 | HIP 72099 | 19.48 |
| 2026-02-20 12:00 | 14:46:25.61 | -34:28:11.3 | HIP 72099 | 19.05 |
| 2026-02-21 00:00 | 14:46:22.80 | -34:28:35.9 | HIP 72099 | 18.61 |
| 2026-02-21 12:00 | 14:46:19.93 | -34:29:00.1 | HIP 72099 | 18.18 |
| 2026-02-22 00:00 | 14:46:16.98 | -34:29:24.0 | HIP 72099 | 17.75 |
| 2026-02-22 12:00 | 14:46:13.96 | -34:29:47.6 | HIP 72099 | 17.33 |
| 2026-02-23 00:00 | 14:46:10.88 | -34:30:10.9 | HIP 72099 | 16.91 |
| 2026-02-23 12:00 | 14:46:07.73 | -34:30:33.8 | HIP 72099 | 16.50 |
| 2026-02-24 00:00 | 14:46:04.51 | -34:30:56.5 | HIP 72099 | 16.10 |