| 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) |
| 2026-03-26 00:00 |
22:14:40.38 |
-18:12:41.4 |
HIP 109918 |
15.74 |
| 2026-03-26 12:00 |
22:14:41.32 |
-18:12:37.3 |
HIP 109918 |
15.50 |
| 2026-03-27 00:00 |
22:14:42.26 |
-18:12:33.3 |
HIP 109918 |
15.27 |
| 2026-03-27 12:00 |
22:14:43.19 |
-18:12:29.3 |
HIP 109918 |
15.04 |
| 2026-03-28 00:00 |
22:14:44.11 |
-18:12:25.4 |
HIP 109918 |
14.81 |
| 2026-03-28 12:00 |
22:14:45.04 |
-18:12:21.5 |
HIP 109918 |
14.58 |
| 2026-03-29 00:00 |
22:14:45.95 |
-18:12:17.6 |
HIP 109918 |
14.36 |
| 2026-03-29 12:00 |
22:14:46.86 |
-18:12:13.8 |
HIP 109918 |
14.13 |
| 2026-03-30 00:00 |
22:14:47.76 |
-18:12:10.0 |
HIP 109918 |
13.91 |
| 2026-03-30 12:00 |
22:14:48.66 |
-18:12:06.3 |
HIP 109918 |
13.69 |
| 2026-03-31 00:00 |
22:14:49.55 |
-18:12:02.7 |
HIP 109918 |
13.47 |
| 2026-03-31 12:00 |
22:14:50.44 |
-18:11:59.0 |
HIP 109918 |
13.25 |
| 2026-04-01 00:00 |
22:14:51.32 |
-18:11:55.5 |
HIP 109918 |
13.03 |
| 2026-04-01 12:00 |
22:14:52.19 |
-18:11:51.9 |
HIP 109918 |
12.81 |
| 2026-04-02 00:00 |
22:14:53.06 |
-18:11:48.5 |
HIP 109918 |
12.60 |
| 2026-04-02 12:00 |
22:14:53.92 |
-18:11:45.0 |
HIP 109918 |
12.39 |
| 2026-04-03 00:00 |
22:14:54.77 |
-18:11:41.6 |
HIP 109918 |
12.18 |
| 2026-04-03 12:00 |
22:14:55.62 |
-18:11:38.3 |
HIP 109918 |
11.97 |
| 2026-04-04 00:00 |
22:14:56.47 |
-18:11:35.0 |
HIP 109918 |
11.76 |
| 2026-04-04 12:00 |
22:14:57.30 |
-18:11:31.8 |
HIP 109918 |
11.56 |
| 2026-04-05 00:00 |
22:14:58.13 |
-18:11:28.6 |
HIP 109918 |
11.35 |
| 2026-04-05 12:00 |
22:14:58.95 |
-18:11:25.5 |
HIP 109918 |
11.15 |
| 2026-04-06 00:00 |
22:14:59.77 |
-18:11:22.4 |
HIP 109918 |
10.95 |
| 2026-04-06 12:00 |
22:15:00.58 |
-18:11:19.3 |
HIP 109918 |
10.75 |
| 2026-04-07 00:00 |
22:15:01.38 |
-18:11:16.3 |
HIP 109918 |
10.55 |
| 2026-04-07 12:00 |
22:15:02.18 |
-18:11:13.4 |
HIP 109918 |
10.36 |
| 2026-04-08 00:00 |
22:15:02.97 |
-18:11:10.5 |
HIP 109918 |
10.16 |
| 2026-04-08 12:00 |
22:15:03.75 |
-18:11:07.7 |
HIP 109918 |
9.97 |
| 2026-04-09 00:00 |
22:15:04.52 |
-18:11:04.9 |
HIP 109918 |
9.78 |
| 2026-04-09 12:00 |
22:15:05.29 |
-18:11:02.1 |
HIP 109918 |
9.59 |
| 2026-04-10 00:00 |
22:15:06.05 |
-18:10:59.4 |
HIP 109918 |
9.41 |
| 2026-04-10 12:00 |
22:15:06.81 |
-18:10:56.8 |
HIP 109918 |
9.22 |
| 2026-04-11 00:00 |
22:15:07.55 |
-18:10:54.2 |
HIP 109918 |
9.04 |
| 2026-04-11 12:00 |
22:15:08.29 |
-18:10:51.7 |
HIP 109918 |
8.86 |
| 2026-04-12 00:00 |
22:15:09.03 |
-18:10:49.2 |
HIP 109918 |
8.68 |
| 2026-04-12 12:00 |
22:15:09.75 |
-18:10:46.8 |
HIP 109918 |
8.51 |
| 2026-04-13 00:00 |
22:15:10.47 |
-18:10:44.4 |
HIP 109918 |
8.33 |
| 2026-04-13 12:00 |
22:15:11.18 |
-18:10:42.1 |
HIP 109918 |
8.16 |
| 2026-04-14 00:00 |
22:15:11.88 |
-18:10:39.8 |
HIP 109918 |
7.99 |
| 2026-04-14 12:00 |
22:15:12.57 |
-18:10:37.6 |
HIP 109918 |
7.82 |
| 2026-04-15 00:00 |
22:15:13.26 |
-18:10:35.4 |
HIP 109918 |
7.65 |
| 2026-04-15 12:00 |
22:15:13.94 |
-18:10:33.3 |
HIP 109918 |
7.49 |
| 2026-04-16 00:00 |
22:15:14.61 |
-18:10:31.2 |
HIP 109918 |
7.32 |