| Parameter |
Value |
| Designation |
C/1963 F1 (Alcock) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1963-05-05T21:06:43.280640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:17Z |
| Obs used |
25 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1963-05-15.0000000 |
| e |
0.99791950 |
| q (au) |
1.537080 |
| a (au) |
738.804223 |
| i (deg) |
86.218793 |
| Ω (om, deg) |
43.465153 |
| ω (w, deg) |
146.621136 |
| M (ma, deg) |
0.000448 |
Magnitude
Scatter + Global Linear
$$
M_a = (4.297 + 5.819\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
4.297 |
| n |
5.819 |
| gf |
1.000 |
| gb |
-0.539 |
| 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) |
| 2026-05-12 00:00 |
03:30:59.75 |
-30:27:31.9 |
HIP 16413 |
5.69 |
| 2026-05-12 12:00 |
03:31:01.26 |
-30:27:27.1 |
HIP 16413 |
5.49 |
| 2026-05-13 00:00 |
03:31:02.77 |
-30:27:22.4 |
HIP 16413 |
5.30 |
| 2026-05-13 12:00 |
03:31:04.27 |
-30:27:17.9 |
HIP 16413 |
5.12 |
| 2026-05-14 00:00 |
03:31:05.78 |
-30:27:13.5 |
HIP 16413 |
4.95 |
| 2026-05-14 12:00 |
03:31:07.29 |
-30:27:09.2 |
HIP 16413 |
4.80 |
| 2026-05-15 00:00 |
03:31:08.80 |
-30:27:05.1 |
HIP 16413 |
4.67 |
| 2026-05-15 12:00 |
03:31:10.31 |
-30:27:01.0 |
HIP 16413 |
4.56 |
| 2026-05-16 00:00 |
03:31:11.82 |
-30:26:57.2 |
HIP 16413 |
4.46 |
| 2026-05-16 12:00 |
03:31:13.33 |
-30:26:53.4 |
HIP 16413 |
4.39 |
| 2026-05-17 00:00 |
03:31:14.84 |
-30:26:49.8 |
HIP 16413 |
4.34 |
| 2026-05-17 12:00 |
03:31:16.35 |
-30:26:46.3 |
HIP 16413 |
4.31 |
| 2026-05-18 00:00 |
03:31:17.86 |
-30:26:42.9 |
HIP 16413 |
4.31 |
| 2026-05-18 12:00 |
03:31:19.37 |
-30:26:39.7 |
HIP 16413 |
4.33 |
| 2026-05-19 00:00 |
03:31:20.88 |
-30:26:36.6 |
HIP 16413 |
4.37 |
| 2026-05-19 12:00 |
03:31:22.39 |
-30:26:33.6 |
HIP 16413 |
4.43 |
| 2026-05-20 00:00 |
03:31:23.90 |
-30:26:30.8 |
HIP 16413 |
4.51 |
| 2026-05-20 12:00 |
03:31:25.41 |
-30:26:28.1 |
HIP 16413 |
4.62 |
| 2026-05-21 00:00 |
03:31:26.91 |
-30:26:25.5 |
HIP 16413 |
4.74 |
| 2026-05-21 12:00 |
03:31:28.42 |
-30:26:23.1 |
HIP 16413 |
4.88 |
| 2026-05-22 00:00 |
03:31:29.92 |
-30:26:20.8 |
HIP 16413 |
5.03 |
| 2026-05-22 12:00 |
03:31:31.42 |
-30:26:18.6 |
HIP 16413 |
5.20 |
| 2026-05-23 00:00 |
03:31:32.92 |
-30:26:16.5 |
HIP 16413 |
5.38 |
| 2026-05-23 12:00 |
03:31:34.42 |
-30:26:14.6 |
HIP 16413 |
5.57 |
| 2026-05-24 00:00 |
03:31:35.92 |
-30:26:12.8 |
HIP 16413 |
5.77 |
| 2026-05-24 12:00 |
03:31:37.42 |
-30:26:11.2 |
HIP 16413 |
5.98 |
| 2026-05-25 00:00 |
03:31:38.91 |
-30:26:09.7 |
HIP 16413 |
6.20 |
| 2026-05-25 12:00 |
03:31:40.40 |
-30:26:08.3 |
HIP 16413 |
6.43 |
| 2026-05-26 00:00 |
03:31:41.90 |
-30:26:07.0 |
HIP 16413 |
6.66 |
| 2026-05-26 12:00 |
03:31:43.38 |
-30:26:05.9 |
HIP 16413 |
6.89 |
| 2026-05-27 00:00 |
03:31:44.87 |
-30:26:04.9 |
HIP 16413 |
7.14 |
| 2026-05-27 12:00 |
03:31:46.35 |
-30:26:04.1 |
HIP 16413 |
7.38 |
| 2026-05-28 00:00 |
03:31:47.84 |
-30:26:03.3 |
HIP 16413 |
7.63 |
| 2026-05-28 12:00 |
03:31:49.32 |
-30:26:02.7 |
HIP 16413 |
7.88 |
| 2026-05-29 00:00 |
03:31:50.79 |
-30:26:02.3 |
HIP 16413 |
8.14 |
| 2026-05-29 12:00 |
03:31:52.27 |
-30:26:01.9 |
HIP 16413 |
8.40 |
| 2026-05-30 00:00 |
03:31:53.74 |
-30:26:01.7 |
HIP 16413 |
8.66 |
| 2026-05-30 12:00 |
03:31:55.21 |
-30:26:01.6 |
HIP 16413 |
8.92 |
| 2026-05-31 00:00 |
03:31:56.67 |
-30:26:01.7 |
HIP 16413 |
9.18 |
| 2026-05-31 12:00 |
03:31:58.14 |
-30:26:01.9 |
HIP 16413 |
9.45 |
| 2026-06-01 00:00 |
03:31:59.59 |
-30:26:02.2 |
HIP 16413 |
9.71 |
| 2026-06-01 12:00 |
03:32:01.05 |
-30:26:02.7 |
HIP 16413 |
9.98 |
| 2026-06-02 00:00 |
03:32:02.50 |
-30:26:03.2 |
HIP 16413 |
10.25 |