| Parameter |
Value |
| Designation |
C/1959 Q1 (Alcock) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1959-08-17T14:42:54.362880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:14Z |
| Obs used |
22 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1959-09-21.0000000 |
| e |
1.00130906 |
| q (au) |
1.150410 |
| a (au) |
-878.806801 |
| i (deg) |
48.258940 |
| Ω (om, deg) |
159.919935 |
| ω (w, deg) |
124.713032 |
| M (ma, deg) |
0.001301 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.983 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.983 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1959-08-25 |
1959-11-05 |
+39.7685 |
-2.674 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
06:30:21.89 |
-20:47:34.7 |
HIP 31094 |
16.38 |
| 2026-03-26 12:00 |
06:30:21.85 |
-20:47:21.1 |
HIP 31094 |
16.34 |
| 2026-03-27 00:00 |
06:30:21.82 |
-20:47:07.6 |
HIP 31094 |
16.30 |
| 2026-03-27 12:00 |
06:30:21.81 |
-20:46:54.0 |
HIP 31094 |
16.26 |
| 2026-03-28 00:00 |
06:30:21.80 |
-20:46:40.5 |
HIP 31094 |
16.23 |
| 2026-03-28 12:00 |
06:30:21.81 |
-20:46:27.0 |
HIP 31094 |
16.19 |
| 2026-03-29 00:00 |
06:30:21.83 |
-20:46:13.4 |
HIP 31094 |
16.16 |
| 2026-03-29 12:00 |
06:30:21.86 |
-20:46:00.0 |
HIP 31094 |
16.12 |
| 2026-03-30 00:00 |
06:30:21.91 |
-20:45:46.4 |
HIP 31094 |
16.08 |
| 2026-03-30 12:00 |
06:30:21.96 |
-20:45:32.9 |
HIP 31094 |
16.05 |
| 2026-03-31 00:00 |
06:30:22.03 |
-20:45:19.4 |
HIP 31094 |
16.01 |
| 2026-03-31 12:00 |
06:30:22.11 |
-20:45:06.0 |
HIP 31094 |
15.98 |
| 2026-04-01 00:00 |
06:30:22.20 |
-20:44:52.5 |
HIP 31094 |
15.95 |
| 2026-04-01 12:00 |
06:30:22.30 |
-20:44:39.1 |
HIP 31094 |
15.91 |
| 2026-04-02 00:00 |
06:30:22.41 |
-20:44:25.7 |
HIP 31094 |
15.88 |
| 2026-04-02 12:00 |
06:30:22.54 |
-20:44:12.3 |
HIP 31094 |
15.85 |
| 2026-04-03 00:00 |
06:30:22.68 |
-20:43:58.9 |
HIP 31094 |
15.81 |
| 2026-04-03 12:00 |
06:30:22.82 |
-20:43:45.6 |
HIP 31094 |
15.78 |
| 2026-04-04 00:00 |
06:30:22.98 |
-20:43:32.2 |
HIP 31094 |
15.75 |
| 2026-04-04 12:00 |
06:30:23.16 |
-20:43:18.9 |
HIP 31094 |
15.72 |
| 2026-04-05 00:00 |
06:30:23.34 |
-20:43:05.6 |
HIP 31094 |
15.69 |
| 2026-04-05 12:00 |
06:30:23.54 |
-20:42:52.4 |
HIP 31094 |
15.66 |
| 2026-04-06 00:00 |
06:30:23.74 |
-20:42:39.1 |
HIP 31094 |
15.63 |
| 2026-04-06 12:00 |
06:30:23.96 |
-20:42:25.9 |
HIP 31094 |
15.60 |
| 2026-04-07 00:00 |
06:30:24.19 |
-20:42:12.7 |
HIP 31094 |
15.57 |
| 2026-04-07 12:00 |
06:30:24.43 |
-20:41:59.5 |
HIP 31094 |
15.54 |
| 2026-04-08 00:00 |
06:30:24.68 |
-20:41:46.4 |
HIP 31094 |
15.52 |
| 2026-04-08 12:00 |
06:30:24.95 |
-20:41:33.3 |
HIP 31094 |
15.49 |
| 2026-04-09 00:00 |
06:30:25.22 |
-20:41:20.2 |
HIP 31094 |
15.46 |
| 2026-04-09 12:00 |
06:30:25.51 |
-20:41:07.2 |
HIP 31094 |
15.44 |
| 2026-04-10 00:00 |
06:30:25.81 |
-20:40:54.2 |
HIP 31094 |
15.41 |
| 2026-04-10 12:00 |
06:30:26.12 |
-20:40:41.2 |
HIP 31094 |
15.39 |
| 2026-04-11 00:00 |
06:30:26.44 |
-20:40:28.3 |
HIP 31094 |
15.36 |
| 2026-04-11 12:00 |
06:30:26.78 |
-20:40:15.3 |
HIP 31094 |
15.34 |
| 2026-04-12 00:00 |
06:30:27.12 |
-20:40:02.5 |
HIP 31094 |
15.31 |
| 2026-04-12 12:00 |
06:30:27.48 |
-20:39:49.6 |
HIP 31094 |
15.29 |
| 2026-04-13 00:00 |
06:30:27.84 |
-20:39:36.8 |
HIP 31094 |
15.27 |
| 2026-04-13 12:00 |
06:30:28.22 |
-20:39:24.1 |
HIP 31094 |
15.25 |
| 2026-04-14 00:00 |
06:30:28.61 |
-20:39:11.3 |
HIP 31094 |
15.23 |
| 2026-04-14 12:00 |
06:30:29.01 |
-20:38:58.7 |
HIP 31094 |
15.21 |
| 2026-04-15 00:00 |
06:30:29.42 |
-20:38:46.0 |
HIP 31094 |
15.19 |
| 2026-04-15 12:00 |
06:30:29.84 |
-20:38:33.4 |
HIP 31094 |
15.17 |
| 2026-04-16 00:00 |
06:30:30.28 |
-20:38:20.9 |
HIP 31094 |
15.16 |