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) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 02:32:29.80 | +29:53:00.5 | HIP 11869 | 9.60 |
| 2026-09-20 12:00 | 02:32:28.57 | +29:52:59.1 | HIP 11869 | 9.85 |
| 2026-09-21 00:00 | 02:32:27.32 | +29:52:57.6 | HIP 11869 | 10.09 |
| 2026-09-21 12:00 | 02:32:26.07 | +29:52:56.0 | HIP 11869 | 10.34 |
| 2026-09-22 00:00 | 02:32:24.81 | +29:52:54.4 | HIP 11869 | 10.60 |
| 2026-09-22 12:00 | 02:32:23.54 | +29:52:52.6 | HIP 11869 | 10.85 |
| 2026-09-23 00:00 | 02:32:22.26 | +29:52:50.8 | HIP 11869 | 11.11 |
| 2026-09-23 12:00 | 02:32:20.97 | +29:52:48.9 | HIP 11869 | 11.38 |
| 2026-09-24 00:00 | 02:32:19.67 | +29:52:47.0 | HIP 11869 | 11.65 |
| 2026-09-24 12:00 | 02:32:18.36 | +29:52:44.9 | HIP 11869 | 11.92 |
| 2026-09-25 00:00 | 02:32:17.04 | +29:52:42.8 | HIP 11869 | 12.19 |
| 2026-09-25 12:00 | 02:32:15.71 | +29:52:40.6 | HIP 11869 | 12.47 |
| 2026-09-26 00:00 | 02:32:14.37 | +29:52:38.3 | HIP 11869 | 12.74 |
| 2026-09-26 12:00 | 02:32:13.03 | +29:52:36.0 | HIP 11869 | 13.03 |
| 2026-09-27 00:00 | 02:32:11.67 | +29:52:33.6 | HIP 11869 | 13.31 |
| 2026-09-27 12:00 | 02:32:10.31 | +29:52:31.0 | HIP 11869 | 13.60 |
| 2026-09-28 00:00 | 02:32:08.94 | +29:52:28.5 | HIP 11869 | 13.89 |
| 2026-09-28 12:00 | 02:32:07.56 | +29:52:25.8 | HIP 11869 | 14.18 |
| 2026-09-29 00:00 | 02:32:06.17 | +29:52:23.1 | HIP 11869 | 14.48 |
| 2026-09-29 12:00 | 02:32:04.77 | +29:52:20.2 | HIP 11869 | 14.78 |
| 2026-09-30 00:00 | 02:32:03.36 | +29:52:17.3 | HIP 11869 | 15.08 |
| 2026-09-30 12:00 | 02:32:01.95 | +29:52:14.4 | HIP 11869 | 15.38 |
| 2026-10-01 00:00 | 02:32:00.52 | +29:52:11.3 | HIP 11869 | 15.69 |
| 2026-10-01 12:00 | 02:31:59.09 | +29:52:08.2 | HIP 11869 | 16.00 |
| 2026-10-02 00:00 | 02:31:57.66 | +29:52:05.0 | HIP 11869 | 16.31 |
| 2026-10-02 12:00 | 02:31:56.21 | +29:52:01.7 | HIP 11869 | 16.62 |
| 2026-10-03 00:00 | 02:31:54.75 | +29:51:58.3 | HIP 11869 | 16.93 |
| 2026-10-03 12:00 | 02:31:53.29 | +29:51:54.9 | HIP 11869 | 17.25 |
| 2026-10-04 00:00 | 02:31:51.82 | +29:51:51.4 | HIP 11869 | 17.57 |
| 2026-10-04 12:00 | 02:31:50.35 | +29:51:47.8 | HIP 11869 | 17.89 |
| 2026-10-05 00:00 | 02:31:48.86 | +29:51:44.1 | HIP 11869 | 18.21 |
| 2026-10-05 12:00 | 02:31:47.37 | +29:51:40.4 | HIP 11869 | 18.54 |
| 2026-10-06 00:00 | 02:31:45.87 | +29:51:36.6 | HIP 11869 | 18.87 |
| 2026-10-06 12:00 | 02:31:44.37 | +29:51:32.7 | HIP 11869 | 19.20 |
| 2026-10-07 00:00 | 02:31:42.85 | +29:51:28.7 | HIP 11869 | 19.53 |
| 2026-10-07 12:00 | 02:31:41.34 | +29:51:24.7 | HIP 11869 | 19.86 |
| 2026-10-08 00:00 | 02:31:39.81 | +29:51:20.6 | HIP 11869 | 20.20 |
| 2026-10-08 12:00 | 02:31:38.28 | +29:51:16.4 | HIP 11869 | 20.53 |
| 2026-10-09 00:00 | 02:31:36.74 | +29:51:12.1 | HIP 11869 | 20.87 |
| 2026-10-09 12:00 | 02:31:35.19 | +29:51:07.8 | HIP 11869 | 21.21 |
| 2026-10-10 00:00 | 02:31:33.64 | +29:51:03.4 | HIP 11869 | 21.55 |
| 2026-10-10 12:00 | 02:31:32.08 | +29:50:58.9 | HIP 11869 | 21.90 |
| 2026-10-11 00:00 | 02:31:30.52 | +29:50:54.3 | HIP 11869 | 22.24 |