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) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 02:33:30.65 | +29:48:28.9 | HIP 11869 | 10.61 |
| 2026-07-29 12:00 | 02:33:30.79 | +29:48:34.9 | HIP 11869 | 10.53 |
| 2026-07-30 00:00 | 02:33:30.91 | +29:48:40.8 | HIP 11869 | 10.46 |
| 2026-07-30 12:00 | 02:33:31.02 | +29:48:46.7 | HIP 11869 | 10.38 |
| 2026-07-31 00:00 | 02:33:31.12 | +29:48:52.6 | HIP 11869 | 10.31 |
| 2026-07-31 12:00 | 02:33:31.20 | +29:48:58.3 | HIP 11869 | 10.23 |
| 2026-08-01 00:00 | 02:33:31.27 | +29:49:04.0 | HIP 11869 | 10.16 |
| 2026-08-01 12:00 | 02:33:31.32 | +29:49:09.7 | HIP 11869 | 10.08 |
| 2026-08-02 00:00 | 02:33:31.37 | +29:49:15.3 | HIP 11869 | 10.01 |
| 2026-08-02 12:00 | 02:33:31.39 | +29:49:20.9 | HIP 11869 | 9.93 |
| 2026-08-03 00:00 | 02:33:31.41 | +29:49:26.4 | HIP 11869 | 9.85 |
| 2026-08-03 12:00 | 02:33:31.40 | +29:49:31.8 | HIP 11869 | 9.77 |
| 2026-08-04 00:00 | 02:33:31.39 | +29:49:37.2 | HIP 11869 | 9.70 |
| 2026-08-04 12:00 | 02:33:31.36 | +29:49:42.5 | HIP 11869 | 9.62 |
| 2026-08-05 00:00 | 02:33:31.32 | +29:49:47.8 | HIP 11869 | 9.54 |
| 2026-08-05 12:00 | 02:33:31.26 | +29:49:53.0 | HIP 11869 | 9.46 |
| 2026-08-06 00:00 | 02:33:31.19 | +29:49:58.2 | HIP 11869 | 9.38 |
| 2026-08-06 12:00 | 02:33:31.10 | +29:50:03.2 | HIP 11869 | 9.29 |
| 2026-08-07 00:00 | 02:33:31.01 | +29:50:08.3 | HIP 11869 | 9.21 |
| 2026-08-07 12:00 | 02:33:30.89 | +29:50:13.3 | HIP 11869 | 9.13 |
| 2026-08-08 00:00 | 02:33:30.77 | +29:50:18.2 | HIP 11869 | 9.05 |
| 2026-08-08 12:00 | 02:33:30.62 | +29:50:23.0 | HIP 11869 | 8.96 |
| 2026-08-09 00:00 | 02:33:30.47 | +29:50:27.8 | HIP 11869 | 8.88 |
| 2026-08-09 12:00 | 02:33:30.30 | +29:50:32.6 | HIP 11869 | 8.79 |
| 2026-08-10 00:00 | 02:33:30.12 | +29:50:37.2 | HIP 11869 | 8.70 |
| 2026-08-10 12:00 | 02:33:29.92 | +29:50:41.8 | HIP 11869 | 8.61 |
| 2026-08-11 00:00 | 02:33:29.71 | +29:50:46.4 | HIP 11869 | 8.53 |
| 2026-08-11 12:00 | 02:33:29.48 | +29:50:50.9 | HIP 11869 | 8.44 |
| 2026-08-12 00:00 | 02:33:29.24 | +29:50:55.3 | HIP 11869 | 8.35 |
| 2026-08-12 12:00 | 02:33:28.99 | +29:50:59.6 | HIP 11869 | 8.26 |
| 2026-08-13 00:00 | 02:33:28.72 | +29:51:03.9 | HIP 11869 | 8.16 |
| 2026-08-13 12:00 | 02:33:28.44 | +29:51:08.2 | HIP 11869 | 8.07 |
| 2026-08-14 00:00 | 02:33:28.14 | +29:51:12.3 | HIP 11869 | 7.98 |
| 2026-08-14 12:00 | 02:33:27.83 | +29:51:16.4 | HIP 11869 | 7.88 |
| 2026-08-15 00:00 | 02:33:27.51 | +29:51:20.4 | HIP 11869 | 7.79 |
| 2026-08-15 12:00 | 02:33:27.17 | +29:51:24.4 | HIP 11869 | 7.70 |
| 2026-08-16 00:00 | 02:33:26.82 | +29:51:28.3 | HIP 11869 | 7.60 |
| 2026-08-16 12:00 | 02:33:26.45 | +29:51:32.1 | HIP 11869 | 7.50 |
| 2026-08-17 00:00 | 02:33:26.07 | +29:51:35.9 | HIP 11869 | 7.41 |
| 2026-08-17 12:00 | 02:33:25.68 | +29:51:39.6 | HIP 11869 | 7.31 |
| 2026-08-18 00:00 | 02:33:25.27 | +29:51:43.2 | HIP 11869 | 7.21 |
| 2026-08-18 12:00 | 02:33:24.85 | +29:51:46.8 | HIP 11869 | 7.11 |
| 2026-08-19 00:00 | 02:33:24.41 | +29:51:50.3 | HIP 11869 | 7.02 |