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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 02:30:49.43 | +29:27:56.9 | HIP 11823 | 24.32 |
| 2026-05-12 12:00 | 02:30:51.05 | +29:28:04.4 | HIP 11823 | 24.04 |
| 2026-05-13 00:00 | 02:30:52.67 | +29:28:11.9 | HIP 11823 | 23.77 |
| 2026-05-13 12:00 | 02:30:54.28 | +29:28:19.5 | HIP 11823 | 23.50 |
| 2026-05-14 00:00 | 02:30:55.89 | +29:28:27.1 | HIP 11823 | 23.23 |
| 2026-05-14 12:00 | 02:30:57.50 | +29:28:34.7 | HIP 11823 | 22.97 |
| 2026-05-15 00:00 | 02:30:59.11 | +29:28:42.4 | HIP 11823 | 22.71 |
| 2026-05-15 12:00 | 02:31:00.71 | +29:28:50.0 | HIP 11823 | 22.45 |
| 2026-05-16 00:00 | 02:31:02.31 | +29:28:57.8 | HIP 11823 | 22.20 |
| 2026-05-16 12:00 | 02:31:03.90 | +29:29:05.5 | HIP 11823 | 21.95 |
| 2026-05-17 00:00 | 02:31:05.49 | +29:29:13.3 | HIP 11823 | 21.71 |
| 2026-05-17 12:00 | 02:31:07.08 | +29:29:21.1 | HIP 11823 | 21.47 |
| 2026-05-18 00:00 | 02:31:08.66 | +29:29:29.0 | HIP 11823 | 21.24 |
| 2026-05-18 12:00 | 02:31:10.24 | +29:29:36.8 | HIP 11823 | 21.01 |
| 2026-05-19 00:00 | 02:31:11.82 | +29:29:44.7 | HIP 11823 | 20.79 |
| 2026-05-19 12:00 | 02:31:13.39 | +29:29:52.7 | HIP 11823 | 20.57 |
| 2026-05-20 00:00 | 02:31:14.96 | +29:30:00.6 | HIP 11823 | 20.36 |
| 2026-05-20 12:00 | 02:31:16.52 | +29:30:08.6 | HIP 11823 | 20.15 |
| 2026-05-21 00:00 | 02:31:18.08 | +29:30:16.6 | HIP 11823 | 19.95 |
| 2026-05-21 12:00 | 02:31:19.64 | +29:30:24.6 | HIP 11823 | 19.76 |
| 2026-05-22 00:00 | 02:31:21.19 | +29:30:32.7 | HIP 11823 | 19.57 |
| 2026-05-22 12:00 | 02:31:22.73 | +29:30:40.8 | HIP 11823 | 19.38 |
| 2026-05-23 00:00 | 02:31:24.27 | +29:30:48.9 | HIP 11823 | 19.21 |
| 2026-05-23 12:00 | 02:31:25.80 | +29:30:57.0 | HIP 11823 | 19.03 |
| 2026-05-24 00:00 | 02:31:27.33 | +29:31:05.2 | HIP 11823 | 18.87 |
| 2026-05-24 12:00 | 02:31:28.86 | +29:31:13.3 | HIP 11823 | 18.71 |
| 2026-05-25 00:00 | 02:31:30.38 | +29:31:21.5 | HIP 11823 | 18.56 |
| 2026-05-25 12:00 | 02:31:31.89 | +29:31:29.7 | HIP 11823 | 18.41 |
| 2026-05-26 00:00 | 02:31:33.40 | +29:31:38.0 | HIP 11823 | 18.28 |
| 2026-05-26 12:00 | 02:31:34.90 | +29:31:46.2 | HIP 11823 | 18.15 |
| 2026-05-27 00:00 | 02:31:36.40 | +29:31:54.5 | HIP 11823 | 18.02 |
| 2026-05-27 12:00 | 02:31:37.89 | +29:32:02.8 | HIP 11823 | 17.91 |
| 2026-05-28 00:00 | 02:31:39.38 | +29:32:11.1 | HIP 11823 | 17.80 |
| 2026-05-28 12:00 | 02:31:40.86 | +29:32:19.4 | HIP 11823 | 17.69 |
| 2026-05-29 00:00 | 02:31:42.33 | +29:32:27.7 | HIP 11823 | 17.60 |
| 2026-05-29 12:00 | 02:31:43.80 | +29:32:36.1 | HIP 11823 | 17.51 |
| 2026-05-30 00:00 | 02:31:45.26 | +29:32:44.4 | HIP 11823 | 17.43 |
| 2026-05-30 12:00 | 02:31:46.71 | +29:32:52.8 | HIP 11823 | 17.36 |
| 2026-05-31 00:00 | 02:31:48.16 | +29:33:01.2 | HIP 11823 | 17.30 |
| 2026-05-31 12:00 | 02:31:49.60 | +29:33:09.6 | HIP 11823 | 17.24 |
| 2026-06-01 00:00 | 02:31:51.04 | +29:33:18.1 | HIP 11823 | 17.19 |
| 2026-06-01 12:00 | 02:31:52.46 | +29:33:26.5 | HIP 11823 | 17.15 |
| 2026-06-02 00:00 | 02:31:53.89 | +29:33:34.9 | HIP 11823 | 17.12 |