C/2002 V1 (NEAT)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2002 V1 (NEAT) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2003-02-18T07:05:52.609920Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:30:22Z |
| Obs used | 1510 |
| NEO | - |
| M1 | 10.400 |
| K1 | 14.250 |
| PC | 0.030 |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2002-12-26.0000000 |
| e | 0.99990177 |
| q (au) | 0.099258 |
| a (au) | 1010.516972 |
| i (deg) | 81.706057 |
| Ω (om, deg) | 64.088430 |
| ω (w, deg) | 152.169686 |
| M (ma, deg) | 359.998334 |
Magnitude
Scatter + Global Linear
$$ M_a = (8.600 + 5.819\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 8.600 |
| n | 5.819 |
| gf | 0.800 |
| 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 |
|---|---|---|---|
| 2002-11-06 | 2003-01-09 | +8.2413 | -1.967 |
| 2003-01-09 | 2003-02-16 | -4.0417 | -0.415 |
| 2003-02-18 | 2003-03-14 | -5.0184 | -2.415 |
| 2003-03-14 | 2003-10-22 | +0.7169 | -2.971 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 04:18:33.44 | -12:08:38.4 | HIP 20115 | 24.66 |
| 2026-09-20 12:00 | 04:18:32.48 | -12:09:00.0 | HIP 20212 | 24.83 |
| 2026-09-21 00:00 | 04:18:31.49 | -12:09:21.5 | HIP 20212 | 24.81 |
| 2026-09-21 12:00 | 04:18:30.49 | -12:09:43.1 | HIP 20212 | 24.80 |
| 2026-09-22 00:00 | 04:18:29.47 | -12:10:04.6 | HIP 20212 | 24.80 |
| 2026-09-22 12:00 | 04:18:28.42 | -12:10:26.0 | HIP 20212 | 24.81 |
| 2026-09-23 00:00 | 04:18:27.36 | -12:10:47.5 | HIP 20212 | 24.84 |
| 2026-09-23 12:00 | 04:18:26.27 | -12:11:08.9 | HIP 20212 | 24.88 |
| 2026-09-24 00:00 | 04:18:25.16 | -12:11:30.3 | HIP 20212 | 24.93 |
| 2026-09-24 12:00 | 04:18:24.04 | -12:11:51.7 | HIP 20212 | 25.00 |
| 2026-09-25 00:00 | 04:18:22.89 | -12:12:13.0 | HIP 20212 | 25.07 |
| 2026-09-25 12:00 | 04:18:21.72 | -12:12:34.3 | HIP 20212 | 25.16 |
| 2026-09-26 00:00 | 04:18:20.53 | -12:12:55.6 | HIP 20212 | 25.27 |
| 2026-09-26 12:00 | 04:18:19.32 | -12:13:16.8 | HIP 20212 | 25.38 |
| 2026-09-27 00:00 | 04:18:18.09 | -12:13:38.0 | HIP 20212 | 25.51 |
| 2026-09-27 12:00 | 04:18:16.85 | -12:13:59.2 | HIP 20212 | 25.65 |
| 2026-09-28 00:00 | 04:18:15.58 | -12:14:20.3 | HIP 20212 | 25.80 |
| 2026-09-28 12:00 | 04:18:14.29 | -12:14:41.4 | HIP 20212 | 25.97 |
| 2026-09-29 00:00 | 04:18:12.98 | -12:15:02.5 | HIP 20212 | 26.14 |
| 2026-09-29 12:00 | 04:18:11.65 | -12:15:23.5 | HIP 20212 | 26.33 |
| 2026-09-30 00:00 | 04:18:10.30 | -12:15:44.4 | HIP 20212 | 26.53 |
| 2026-09-30 12:00 | 04:18:08.93 | -12:16:05.3 | HIP 20212 | 26.75 |
| 2026-10-01 00:00 | 04:18:07.54 | -12:16:26.2 | HIP 19948 | 26.97 |
| 2026-10-01 12:00 | 04:18:06.14 | -12:16:47.0 | HIP 19948 | 26.48 |
| 2026-10-02 00:00 | 04:18:04.71 | -12:17:07.7 | HIP 19948 | 26.00 |
| 2026-10-02 12:00 | 04:18:03.26 | -12:17:28.4 | HIP 19948 | 25.50 |
| 2026-10-03 00:00 | 04:18:01.80 | -12:17:49.1 | HIP 19948 | 25.01 |
| 2026-10-03 12:00 | 04:18:00.31 | -12:18:09.7 | HIP 19948 | 24.51 |
| 2026-10-04 00:00 | 04:17:58.81 | -12:18:30.2 | HIP 19948 | 24.01 |
| 2026-10-04 12:00 | 04:17:57.28 | -12:18:50.7 | HIP 19948 | 23.51 |
| 2026-10-05 00:00 | 04:17:55.74 | -12:19:11.1 | HIP 19948 | 23.00 |
| 2026-10-05 12:00 | 04:17:54.18 | -12:19:31.4 | HIP 19948 | 22.49 |
| 2026-10-06 00:00 | 04:17:52.60 | -12:19:51.7 | HIP 19948 | 21.98 |
| 2026-10-06 12:00 | 04:17:51.00 | -12:20:11.9 | HIP 19948 | 21.47 |
| 2026-10-07 00:00 | 04:17:49.39 | -12:20:32.0 | HIP 19948 | 20.95 |
| 2026-10-07 12:00 | 04:17:47.75 | -12:20:52.1 | HIP 19948 | 20.43 |
| 2026-10-08 00:00 | 04:17:46.10 | -12:21:12.1 | HIP 19948 | 19.90 |
| 2026-10-08 12:00 | 04:17:44.42 | -12:21:32.0 | HIP 19948 | 19.38 |
| 2026-10-09 00:00 | 04:17:42.73 | -12:21:51.9 | HIP 19948 | 18.85 |
| 2026-10-09 12:00 | 04:17:41.02 | -12:22:11.6 | HIP 19948 | 18.32 |
| 2026-10-10 00:00 | 04:17:39.30 | -12:22:31.3 | HIP 19948 | 17.78 |
| 2026-10-10 12:00 | 04:17:37.55 | -12:22:50.9 | HIP 19948 | 17.25 |
| 2026-10-11 00:00 | 04:17:35.79 | -12:23:10.4 | HIP 19948 | 16.71 |