C/1959 Q1 (Alcock)
| 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) |
| 2026-02-03 00:00 |
06:31:24.90 |
-21:08:03.9 |
HIP 31092 |
16.31 |
| 2026-02-03 12:00 |
06:31:23.79 |
-21:07:55.0 |
HIP 31092 |
16.47 |
| 2026-02-04 00:00 |
06:31:22.68 |
-21:07:46.0 |
HIP 31092 |
16.64 |
| 2026-02-04 12:00 |
06:31:21.59 |
-21:07:36.9 |
HIP 31092 |
16.82 |
| 2026-02-05 00:00 |
06:31:20.50 |
-21:07:27.8 |
HIP 31092 |
17.00 |
| 2026-02-05 12:00 |
06:31:19.42 |
-21:07:18.5 |
HIP 31092 |
17.19 |
| 2026-02-06 00:00 |
06:31:18.35 |
-21:07:09.2 |
HIP 31092 |
17.38 |
| 2026-02-06 12:00 |
06:31:17.29 |
-21:06:59.7 |
HIP 31092 |
17.57 |
| 2026-02-07 00:00 |
06:31:16.23 |
-21:06:50.2 |
HIP 31092 |
17.77 |
| 2026-02-07 12:00 |
06:31:15.19 |
-21:06:40.6 |
HIP 31092 |
17.97 |
| 2026-02-08 00:00 |
06:31:14.15 |
-21:06:30.9 |
HIP 31092 |
18.18 |
| 2026-02-08 12:00 |
06:31:13.12 |
-21:06:21.1 |
HIP 31092 |
18.38 |
| 2026-02-09 00:00 |
06:31:12.10 |
-21:06:11.2 |
HIP 31092 |
18.60 |
| 2026-02-09 12:00 |
06:31:11.08 |
-21:06:01.3 |
HIP 31092 |
18.81 |
| 2026-02-10 00:00 |
06:31:10.08 |
-21:05:51.3 |
HIP 31092 |
19.03 |
| 2026-02-10 12:00 |
06:31:09.08 |
-21:05:41.1 |
HIP 31092 |
19.25 |
| 2026-02-11 00:00 |
06:31:08.09 |
-21:05:31.0 |
HIP 31092 |
19.47 |
| 2026-02-11 12:00 |
06:31:07.11 |
-21:05:20.7 |
HIP 31092 |
19.69 |
| 2026-02-12 00:00 |
06:31:06.14 |
-21:05:10.3 |
HIP 31092 |
19.92 |
| 2026-02-12 12:00 |
06:31:05.18 |
-21:04:59.9 |
HIP 31092 |
20.15 |
| 2026-02-13 00:00 |
06:31:04.23 |
-21:04:49.4 |
HIP 31092 |
20.38 |
| 2026-02-13 12:00 |
06:31:03.28 |
-21:04:38.8 |
HIP 31092 |
20.62 |
| 2026-02-14 00:00 |
06:31:02.35 |
-21:04:28.1 |
HIP 31092 |
20.85 |
| 2026-02-14 12:00 |
06:31:01.42 |
-21:04:17.4 |
HIP 31092 |
21.09 |
| 2026-02-15 00:00 |
06:31:00.51 |
-21:04:06.6 |
HIP 31094 |
21.23 |
| 2026-02-15 12:00 |
06:30:59.60 |
-21:03:55.7 |
HIP 31094 |
21.13 |
| 2026-02-16 00:00 |
06:30:58.70 |
-21:03:44.7 |
HIP 31094 |
21.03 |
| 2026-02-16 12:00 |
06:30:57.81 |
-21:03:33.7 |
HIP 31094 |
20.93 |
| 2026-02-17 00:00 |
06:30:56.94 |
-21:03:22.6 |
HIP 31094 |
20.83 |
| 2026-02-17 12:00 |
06:30:56.07 |
-21:03:11.4 |
HIP 31094 |
20.74 |
| 2026-02-18 00:00 |
06:30:55.21 |
-21:03:00.2 |
HIP 31094 |
20.64 |
| 2026-02-18 12:00 |
06:30:54.36 |
-21:02:48.9 |
HIP 31094 |
20.55 |
| 2026-02-19 00:00 |
06:30:53.52 |
-21:02:37.5 |
HIP 31094 |
20.46 |
| 2026-02-19 12:00 |
06:30:52.69 |
-21:02:26.1 |
HIP 31094 |
20.37 |
| 2026-02-20 00:00 |
06:30:51.87 |
-21:02:14.6 |
HIP 31094 |
20.28 |
| 2026-02-20 12:00 |
06:30:51.06 |
-21:02:03.0 |
HIP 31094 |
20.19 |
| 2026-02-21 00:00 |
06:30:50.26 |
-21:01:51.4 |
HIP 31094 |
20.11 |
| 2026-02-21 12:00 |
06:30:49.48 |
-21:01:39.7 |
HIP 31094 |
20.02 |
| 2026-02-22 00:00 |
06:30:48.70 |
-21:01:27.9 |
HIP 31094 |
19.94 |
| 2026-02-22 12:00 |
06:30:47.93 |
-21:01:16.1 |
HIP 31094 |
19.86 |
| 2026-02-23 00:00 |
06:30:47.17 |
-21:01:04.3 |
HIP 31094 |
19.77 |
| 2026-02-23 12:00 |
06:30:46.42 |
-21:00:52.3 |
HIP 31094 |
19.69 |
| 2026-02-24 00:00 |
06:30:45.69 |
-21:00:40.3 |
HIP 31094 |
19.61 |