C/1969 Y1 (Bennett)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/1969 Y1 (Bennett) |
| Type | C |
| Perihelion (tp_cal, UTC) | 1970-03-20T01:05:24.547200Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:29:19Z |
| Obs used | 529 |
| NEO | - |
| M1 | 4.600 |
| K1 | 12.000 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 1970-04-12.0000000 |
| e | 0.99629328 |
| q (au) | 0.537620 |
| a (au) | 145.039330 |
| i (deg) | 90.039811 |
| Ω (om, deg) | 224.657683 |
| ω (w, deg) | 354.149089 |
| M (ma, deg) | 0.012952 |
Magnitude
Scatter + Global Linear
$$ M_a = (4.085 + 3.365\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 4.085 |
| n | 3.365 |
| gf | 0.800 |
| gb | -0.500 |
| k | 1.000 |
| 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 |
|---|---|---|---|
| 1969-12-28 | 1970-03-20 | +3.0975 | +0.766 |
| 1970-03-20 | 1970-04-13 | -4.8648 | -1.069 |
| 1970-04-13 | 1970-05-01 | +0.0535 | -0.380 |
| 1970-05-01 | 1970-11-20 | +1.8732 | -0.612 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 02:28:21.41 | +29:19:58.5 | HIP 11579 | 19.60 |
| 2026-03-26 12:00 | 02:28:22.77 | +29:20:00.6 | HIP 11579 | 19.46 |
| 2026-03-27 00:00 | 02:28:24.15 | +29:20:02.8 | HIP 11579 | 19.32 |
| 2026-03-27 12:00 | 02:28:25.53 | +29:20:05.1 | HIP 11579 | 19.18 |
| 2026-03-28 00:00 | 02:28:26.92 | +29:20:07.4 | HIP 11579 | 19.05 |
| 2026-03-28 12:00 | 02:28:28.32 | +29:20:09.8 | HIP 11579 | 18.92 |
| 2026-03-29 00:00 | 02:28:29.73 | +29:20:12.3 | HIP 11579 | 18.80 |
| 2026-03-29 12:00 | 02:28:31.14 | +29:20:14.9 | HIP 11579 | 18.68 |
| 2026-03-30 00:00 | 02:28:32.56 | +29:20:17.5 | HIP 11579 | 18.56 |
| 2026-03-30 12:00 | 02:28:33.99 | +29:20:20.3 | HIP 11579 | 18.46 |
| 2026-03-31 00:00 | 02:28:35.42 | +29:20:23.0 | HIP 11579 | 18.35 |
| 2026-03-31 12:00 | 02:28:36.86 | +29:20:25.9 | HIP 11579 | 18.25 |
| 2026-04-01 00:00 | 02:28:38.31 | +29:20:28.8 | HIP 11579 | 18.16 |
| 2026-04-01 12:00 | 02:28:39.77 | +29:20:31.8 | HIP 11579 | 18.07 |
| 2026-04-02 00:00 | 02:28:41.23 | +29:20:34.9 | HIP 11579 | 17.99 |
| 2026-04-02 12:00 | 02:28:42.69 | +29:20:38.0 | HIP 11579 | 17.91 |
| 2026-04-03 00:00 | 02:28:44.17 | +29:20:41.2 | HIP 11579 | 17.85 |
| 2026-04-03 12:00 | 02:28:45.65 | +29:20:44.5 | HIP 11579 | 17.78 |
| 2026-04-04 00:00 | 02:28:47.13 | +29:20:47.9 | HIP 11579 | 17.73 |
| 2026-04-04 12:00 | 02:28:48.62 | +29:20:51.3 | HIP 11579 | 17.68 |
| 2026-04-05 00:00 | 02:28:50.12 | +29:20:54.8 | HIP 11579 | 17.63 |
| 2026-04-05 12:00 | 02:28:51.62 | +29:20:58.3 | HIP 11579 | 17.60 |
| 2026-04-06 00:00 | 02:28:53.13 | +29:21:02.0 | HIP 11579 | 17.57 |
| 2026-04-06 12:00 | 02:28:54.65 | +29:21:05.6 | HIP 11579 | 17.54 |
| 2026-04-07 00:00 | 02:28:56.17 | +29:21:09.4 | HIP 11579 | 17.53 |
| 2026-04-07 12:00 | 02:28:57.69 | +29:21:13.2 | HIP 11579 | 17.52 |
| 2026-04-08 00:00 | 02:28:59.22 | +29:21:17.1 | HIP 11579 | 17.52 |
| 2026-04-08 12:00 | 02:29:00.76 | +29:21:21.1 | HIP 11579 | 17.53 |
| 2026-04-09 00:00 | 02:29:02.30 | +29:21:25.1 | HIP 11579 | 17.54 |
| 2026-04-09 12:00 | 02:29:03.85 | +29:21:29.2 | HIP 11579 | 17.57 |
| 2026-04-10 00:00 | 02:29:05.40 | +29:21:33.4 | HIP 11579 | 17.60 |
| 2026-04-10 12:00 | 02:29:06.95 | +29:21:37.6 | HIP 11579 | 17.63 |
| 2026-04-11 00:00 | 02:29:08.51 | +29:21:41.9 | HIP 11579 | 17.68 |
| 2026-04-11 12:00 | 02:29:10.08 | +29:21:46.2 | HIP 11579 | 17.73 |
| 2026-04-12 00:00 | 02:29:11.65 | +29:21:50.6 | HIP 11579 | 17.80 |
| 2026-04-12 12:00 | 02:29:13.22 | +29:21:55.1 | HIP 11579 | 17.86 |
| 2026-04-13 00:00 | 02:29:14.80 | +29:21:59.7 | HIP 11579 | 17.94 |
| 2026-04-13 12:00 | 02:29:16.38 | +29:22:04.3 | HIP 11579 | 18.03 |
| 2026-04-14 00:00 | 02:29:17.96 | +29:22:09.0 | HIP 11579 | 18.12 |
| 2026-04-14 12:00 | 02:29:19.55 | +29:22:13.7 | HIP 11579 | 18.22 |
| 2026-04-15 00:00 | 02:29:21.15 | +29:22:18.5 | HIP 11579 | 18.32 |
| 2026-04-15 12:00 | 02:29:22.74 | +29:22:23.4 | HIP 11579 | 18.44 |
| 2026-04-16 00:00 | 02:29:24.34 | +29:22:28.3 | HIP 11579 | 18.56 |