C/1947 F2 (Becvar)
| Parameter |
Value |
| Designation |
C/1947 F2 (Becvar) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1947-05-03T21:55:11.012160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:07Z |
| Obs used |
23 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1947-04-14.0000000 |
| e |
1.00000000 |
| q (au) |
0.961893 |
| a (au) |
- |
| i (deg) |
129.171903 |
| Ω (om, deg) |
323.060604 |
| ω (w, deg) |
182.120598 |
| M (ma, deg) |
- |
Magnitude
Scatter + Global Linear
$$
M_a = (10.618 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.618 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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 |
22:12:49.63 |
-18:22:28.5 |
HIP 109634 |
21.21 |
| 2026-02-03 12:00 |
22:12:50.72 |
-18:22:21.8 |
HIP 109634 |
21.15 |
| 2026-02-04 00:00 |
22:12:51.81 |
-18:22:15.2 |
HIP 109634 |
21.09 |
| 2026-02-04 12:00 |
22:12:52.90 |
-18:22:08.5 |
HIP 109634 |
21.04 |
| 2026-02-05 00:00 |
22:12:53.99 |
-18:22:01.8 |
HIP 109634 |
20.99 |
| 2026-02-05 12:00 |
22:12:55.08 |
-18:21:55.1 |
HIP 109634 |
20.95 |
| 2026-02-06 00:00 |
22:12:56.18 |
-18:21:48.5 |
HIP 109634 |
20.91 |
| 2026-02-06 12:00 |
22:12:57.28 |
-18:21:41.8 |
HIP 109634 |
20.87 |
| 2026-02-07 00:00 |
22:12:58.39 |
-18:21:35.2 |
HIP 109634 |
20.84 |
| 2026-02-07 12:00 |
22:12:59.49 |
-18:21:28.5 |
HIP 109634 |
20.81 |
| 2026-02-08 00:00 |
22:13:00.60 |
-18:21:21.9 |
HIP 109634 |
20.79 |
| 2026-02-08 12:00 |
22:13:01.71 |
-18:21:15.3 |
HIP 109634 |
20.77 |
| 2026-02-09 00:00 |
22:13:02.82 |
-18:21:08.6 |
HIP 109634 |
20.75 |
| 2026-02-09 12:00 |
22:13:03.93 |
-18:21:02.0 |
HIP 109634 |
20.74 |
| 2026-02-10 00:00 |
22:13:05.05 |
-18:20:55.4 |
HIP 109634 |
20.73 |
| 2026-02-10 12:00 |
22:13:06.16 |
-18:20:48.8 |
HIP 109634 |
20.73 |
| 2026-02-11 00:00 |
22:13:07.28 |
-18:20:42.2 |
HIP 109634 |
20.73 |
| 2026-02-11 12:00 |
22:13:08.40 |
-18:20:35.6 |
HIP 109634 |
20.73 |
| 2026-02-12 00:00 |
22:13:09.52 |
-18:20:29.1 |
HIP 109634 |
20.74 |
| 2026-02-12 12:00 |
22:13:10.65 |
-18:20:22.5 |
HIP 109634 |
20.76 |
| 2026-02-13 00:00 |
22:13:11.77 |
-18:20:16.0 |
HIP 109634 |
20.77 |
| 2026-02-13 12:00 |
22:13:12.90 |
-18:20:09.4 |
HIP 109634 |
20.80 |
| 2026-02-14 00:00 |
22:13:14.02 |
-18:20:02.9 |
HIP 109634 |
20.82 |
| 2026-02-14 12:00 |
22:13:15.15 |
-18:19:56.4 |
HIP 109634 |
20.85 |
| 2026-02-15 00:00 |
22:13:16.28 |
-18:19:49.9 |
HIP 109634 |
20.89 |
| 2026-02-15 12:00 |
22:13:17.41 |
-18:19:43.4 |
HIP 109634 |
20.93 |
| 2026-02-16 00:00 |
22:13:18.54 |
-18:19:37.0 |
HIP 109634 |
20.97 |
| 2026-02-16 12:00 |
22:13:19.67 |
-18:19:30.5 |
HIP 109634 |
21.02 |
| 2026-02-17 00:00 |
22:13:20.80 |
-18:19:24.1 |
HIP 109634 |
21.07 |
| 2026-02-17 12:00 |
22:13:21.94 |
-18:19:17.7 |
HIP 109634 |
21.13 |
| 2026-02-18 00:00 |
22:13:23.07 |
-18:19:11.3 |
HIP 109634 |
21.19 |
| 2026-02-18 12:00 |
22:13:24.20 |
-18:19:04.9 |
HIP 109634 |
21.25 |
| 2026-02-19 00:00 |
22:13:25.34 |
-18:18:58.5 |
HIP 109634 |
21.32 |
| 2026-02-19 12:00 |
22:13:26.47 |
-18:18:52.1 |
HIP 109634 |
21.40 |
| 2026-02-20 00:00 |
22:13:27.60 |
-18:18:45.8 |
HIP 109634 |
21.47 |
| 2026-02-20 12:00 |
22:13:28.74 |
-18:18:39.5 |
HIP 109634 |
21.55 |
| 2026-02-21 00:00 |
22:13:29.87 |
-18:18:33.2 |
HIP 109634 |
21.64 |
| 2026-02-21 12:00 |
22:13:31.01 |
-18:18:26.9 |
HIP 109634 |
21.72 |
| 2026-02-22 00:00 |
22:13:32.14 |
-18:18:20.7 |
HIP 109634 |
21.81 |
| 2026-02-22 12:00 |
22:13:33.27 |
-18:18:14.4 |
HIP 109634 |
21.91 |
| 2026-02-23 00:00 |
22:13:34.40 |
-18:18:08.2 |
HIP 109634 |
22.01 |
| 2026-02-23 12:00 |
22:13:35.54 |
-18:18:02.0 |
HIP 109634 |
22.11 |
| 2026-02-24 00:00 |
22:13:36.67 |
-18:17:55.9 |
HIP 109634 |
22.22 |