| 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) |
| 2026-06-01 00:00 |
22:15:38.79 |
-18:11:14.7 |
HIP 109918 |
2.91 |
| 2026-06-01 12:00 |
22:15:38.62 |
-18:11:17.7 |
HIP 109918 |
2.97 |
| 2026-06-02 00:00 |
22:15:38.43 |
-18:11:20.6 |
HIP 109918 |
3.04 |
| 2026-06-02 12:00 |
22:15:38.24 |
-18:11:23.7 |
HIP 109918 |
3.10 |
| 2026-06-03 00:00 |
22:15:38.04 |
-18:11:26.7 |
HIP 109918 |
3.17 |
| 2026-06-03 12:00 |
22:15:37.83 |
-18:11:29.9 |
HIP 109918 |
3.24 |
| 2026-06-04 00:00 |
22:15:37.61 |
-18:11:33.0 |
HIP 109918 |
3.31 |
| 2026-06-04 12:00 |
22:15:37.38 |
-18:11:36.3 |
HIP 109918 |
3.39 |
| 2026-06-05 00:00 |
22:15:37.14 |
-18:11:39.5 |
HIP 109918 |
3.46 |
| 2026-06-05 12:00 |
22:15:36.89 |
-18:11:42.8 |
HIP 109918 |
3.54 |
| 2026-06-06 00:00 |
22:15:36.64 |
-18:11:46.2 |
HIP 109918 |
3.62 |
| 2026-06-06 12:00 |
22:15:36.37 |
-18:11:49.6 |
HIP 109918 |
3.70 |
| 2026-06-07 00:00 |
22:15:36.09 |
-18:11:53.1 |
HIP 109918 |
3.78 |
| 2026-06-07 12:00 |
22:15:35.81 |
-18:11:56.6 |
HIP 109918 |
3.87 |
| 2026-06-08 00:00 |
22:15:35.51 |
-18:12:00.1 |
HIP 109918 |
3.96 |
| 2026-06-08 12:00 |
22:15:35.21 |
-18:12:03.7 |
HIP 109918 |
4.05 |
| 2026-06-09 00:00 |
22:15:34.90 |
-18:12:07.4 |
HIP 109918 |
4.14 |
| 2026-06-09 12:00 |
22:15:34.57 |
-18:12:11.0 |
HIP 109918 |
4.23 |
| 2026-06-10 00:00 |
22:15:34.24 |
-18:12:14.8 |
HIP 109918 |
4.33 |
| 2026-06-10 12:00 |
22:15:33.90 |
-18:12:18.5 |
HIP 109918 |
4.42 |
| 2026-06-11 00:00 |
22:15:33.55 |
-18:12:22.4 |
HIP 109918 |
4.52 |
| 2026-06-11 12:00 |
22:15:33.19 |
-18:12:26.2 |
HIP 109918 |
4.62 |
| 2026-06-12 00:00 |
22:15:32.82 |
-18:12:30.1 |
HIP 109918 |
4.73 |
| 2026-06-12 12:00 |
22:15:32.44 |
-18:12:34.1 |
HIP 109918 |
4.83 |
| 2026-06-13 00:00 |
22:15:32.06 |
-18:12:38.1 |
HIP 109918 |
4.94 |
| 2026-06-13 12:00 |
22:15:31.66 |
-18:12:42.1 |
HIP 109918 |
5.05 |
| 2026-06-14 00:00 |
22:15:31.25 |
-18:12:46.2 |
HIP 109918 |
5.16 |
| 2026-06-14 12:00 |
22:15:30.84 |
-18:12:50.3 |
HIP 109918 |
5.28 |
| 2026-06-15 00:00 |
22:15:30.42 |
-18:12:54.5 |
HIP 109918 |
5.40 |
| 2026-06-15 12:00 |
22:15:29.98 |
-18:12:58.7 |
HIP 109918 |
5.51 |
| 2026-06-16 00:00 |
22:15:29.54 |
-18:13:02.9 |
HIP 109918 |
5.64 |
| 2026-06-16 12:00 |
22:15:29.09 |
-18:13:07.2 |
HIP 109918 |
5.76 |
| 2026-06-17 00:00 |
22:15:28.63 |
-18:13:11.5 |
HIP 109918 |
5.88 |
| 2026-06-17 12:00 |
22:15:28.16 |
-18:13:15.9 |
HIP 109918 |
6.01 |
| 2026-06-18 00:00 |
22:15:27.69 |
-18:13:20.3 |
HIP 109918 |
6.14 |
| 2026-06-18 12:00 |
22:15:27.20 |
-18:13:24.8 |
HIP 109918 |
6.27 |
| 2026-06-19 00:00 |
22:15:26.71 |
-18:13:29.2 |
HIP 109918 |
6.40 |
| 2026-06-19 12:00 |
22:15:26.20 |
-18:13:33.8 |
HIP 109918 |
6.54 |
| 2026-06-20 00:00 |
22:15:25.69 |
-18:13:38.3 |
HIP 109918 |
6.68 |
| 2026-06-20 12:00 |
22:15:25.17 |
-18:13:42.9 |
HIP 109918 |
6.82 |
| 2026-06-21 00:00 |
22:15:24.64 |
-18:13:47.6 |
HIP 109918 |
6.96 |
| 2026-06-21 12:00 |
22:15:24.11 |
-18:13:52.3 |
HIP 109918 |
7.10 |
| 2026-06-22 00:00 |
22:15:23.56 |
-18:13:57.0 |
HIP 109918 |
7.25 |