C/1932 Y1 (Dodwell-Forbes)
| Parameter |
Value |
| Designation |
C/1932 Y1 (Dodwell-Forbes) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1932-12-30T12:36:55.002240Z |
| Orbit solution date (soln_date, UTC) |
2023-12-04T20:32:29Z |
| Obs used |
23 |
| NEO |
- |
| M1 |
9.100 |
| K1 |
15.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1933-01-20.0000000 |
| e |
0.97216017 |
| q (au) |
1.130765 |
| a (au) |
40.616795 |
| i (deg) |
24.502460 |
| Ω (om, deg) |
78.589152 |
| ω (w, deg) |
327.357273 |
| M (ma, deg) |
0.077957 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.943 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.943 |
| n |
6.000 |
| gf |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
15:10:41.60 |
-03:20:03.0 |
HIP 74292 |
15.16 |
| 2026-02-03 12:00 |
15:10:41.79 |
-03:19:58.1 |
HIP 74292 |
15.22 |
| 2026-02-04 00:00 |
15:10:41.98 |
-03:19:53.1 |
HIP 74292 |
15.28 |
| 2026-02-04 12:00 |
15:10:42.15 |
-03:19:48.1 |
HIP 74292 |
15.34 |
| 2026-02-05 00:00 |
15:10:42.31 |
-03:19:43.0 |
HIP 74292 |
15.40 |
| 2026-02-05 12:00 |
15:10:42.46 |
-03:19:37.8 |
HIP 74292 |
15.47 |
| 2026-02-06 00:00 |
15:10:42.59 |
-03:19:32.6 |
HIP 74292 |
15.54 |
| 2026-02-06 12:00 |
15:10:42.71 |
-03:19:27.4 |
HIP 74292 |
15.61 |
| 2026-02-07 00:00 |
15:10:42.81 |
-03:19:22.1 |
HIP 74292 |
15.68 |
| 2026-02-07 12:00 |
15:10:42.91 |
-03:19:16.7 |
HIP 74292 |
15.76 |
| 2026-02-08 00:00 |
15:10:42.99 |
-03:19:11.3 |
HIP 74292 |
15.83 |
| 2026-02-08 12:00 |
15:10:43.05 |
-03:19:05.8 |
HIP 74292 |
15.91 |
| 2026-02-09 00:00 |
15:10:43.10 |
-03:19:00.2 |
HIP 74292 |
16.00 |
| 2026-02-09 12:00 |
15:10:43.14 |
-03:18:54.6 |
HIP 74292 |
16.08 |
| 2026-02-10 00:00 |
15:10:43.17 |
-03:18:49.0 |
HIP 74292 |
16.17 |
| 2026-02-10 12:00 |
15:10:43.18 |
-03:18:43.3 |
HIP 74292 |
16.26 |
| 2026-02-11 00:00 |
15:10:43.18 |
-03:18:37.5 |
HIP 74292 |
16.35 |
| 2026-02-11 12:00 |
15:10:43.17 |
-03:18:31.7 |
HIP 74292 |
16.44 |
| 2026-02-12 00:00 |
15:10:43.14 |
-03:18:25.8 |
HIP 74292 |
16.53 |
| 2026-02-12 12:00 |
15:10:43.10 |
-03:18:19.9 |
HIP 74292 |
16.63 |
| 2026-02-13 00:00 |
15:10:43.05 |
-03:18:13.9 |
HIP 74292 |
16.73 |
| 2026-02-13 12:00 |
15:10:42.98 |
-03:18:07.9 |
HIP 74292 |
16.83 |
| 2026-02-14 00:00 |
15:10:42.90 |
-03:18:01.8 |
HIP 74292 |
16.93 |
| 2026-02-14 12:00 |
15:10:42.80 |
-03:17:55.7 |
HIP 74292 |
17.04 |
| 2026-02-15 00:00 |
15:10:42.70 |
-03:17:49.5 |
HIP 74292 |
17.14 |
| 2026-02-15 12:00 |
15:10:42.58 |
-03:17:43.2 |
HIP 74292 |
17.25 |
| 2026-02-16 00:00 |
15:10:42.44 |
-03:17:37.0 |
HIP 74292 |
17.36 |
| 2026-02-16 12:00 |
15:10:42.29 |
-03:17:30.6 |
HIP 74292 |
17.47 |
| 2026-02-17 00:00 |
15:10:42.13 |
-03:17:24.3 |
HIP 74292 |
17.59 |
| 2026-02-17 12:00 |
15:10:41.96 |
-03:17:17.8 |
HIP 74292 |
17.70 |
| 2026-02-18 00:00 |
15:10:41.77 |
-03:17:11.4 |
HIP 74292 |
17.82 |
| 2026-02-18 12:00 |
15:10:41.57 |
-03:17:04.8 |
HIP 74292 |
17.94 |
| 2026-02-19 00:00 |
15:10:41.36 |
-03:16:58.3 |
HIP 74292 |
18.06 |
| 2026-02-19 12:00 |
15:10:41.13 |
-03:16:51.7 |
HIP 74292 |
18.18 |
| 2026-02-20 00:00 |
15:10:40.89 |
-03:16:45.0 |
HIP 74292 |
18.31 |
| 2026-02-20 12:00 |
15:10:40.64 |
-03:16:38.3 |
HIP 74292 |
18.43 |
| 2026-02-21 00:00 |
15:10:40.37 |
-03:16:31.6 |
HIP 74292 |
18.56 |
| 2026-02-21 12:00 |
15:10:40.09 |
-03:16:24.8 |
HIP 74292 |
18.69 |
| 2026-02-22 00:00 |
15:10:39.80 |
-03:16:17.9 |
HIP 74292 |
18.82 |
| 2026-02-22 12:00 |
15:10:39.49 |
-03:16:11.1 |
HIP 74292 |
18.96 |
| 2026-02-23 00:00 |
15:10:39.17 |
-03:16:04.1 |
HIP 74292 |
19.09 |
| 2026-02-23 12:00 |
15:10:38.84 |
-03:15:57.2 |
HIP 74292 |
19.23 |
| 2026-02-24 00:00 |
15:10:38.49 |
-03:15:50.2 |
HIP 74292 |
19.37 |