C/1979 S1 (Meier)
| Parameter |
Value |
| Designation |
C/1979 S1 (Meier) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1979-10-17T08:06:07.672320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:27Z |
| Obs used |
45 |
| NEO |
- |
| M1 |
4.800 |
| K1 |
46.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1979-11-02.0000000 |
| e |
0.97299836 |
| q (au) |
1.431958 |
| a (au) |
53.032267 |
| i (deg) |
67.079393 |
| Ω (om, deg) |
297.631300 |
| ω (w, deg) |
112.564818 |
| M (ma, deg) |
0.039972 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.190 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.190 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
11:30:56.27 |
-76:04:31.1 |
HIP 56258 |
14.12 |
| 2026-02-03 12:00 |
11:30:50.49 |
-76:04:48.1 |
HIP 56258 |
13.93 |
| 2026-02-04 00:00 |
11:30:44.66 |
-76:05:04.9 |
HIP 56258 |
13.77 |
| 2026-02-04 12:00 |
11:30:38.79 |
-76:05:21.5 |
HIP 56258 |
13.62 |
| 2026-02-05 00:00 |
11:30:32.87 |
-76:05:37.9 |
HIP 56258 |
13.48 |
| 2026-02-05 12:00 |
11:30:26.92 |
-76:05:54.0 |
HIP 56258 |
13.37 |
| 2026-02-06 00:00 |
11:30:20.92 |
-76:06:09.9 |
HIP 56258 |
13.27 |
| 2026-02-06 12:00 |
11:30:14.87 |
-76:06:25.6 |
HIP 56258 |
13.20 |
| 2026-02-07 00:00 |
11:30:08.79 |
-76:06:41.0 |
HIP 56258 |
13.14 |
| 2026-02-07 12:00 |
11:30:02.66 |
-76:06:56.2 |
HIP 56258 |
13.10 |
| 2026-02-08 00:00 |
11:29:56.49 |
-76:07:11.2 |
HIP 56258 |
13.08 |
| 2026-02-08 12:00 |
11:29:50.28 |
-76:07:25.9 |
HIP 56258 |
13.08 |
| 2026-02-09 00:00 |
11:29:44.03 |
-76:07:40.5 |
HIP 56258 |
13.10 |
| 2026-02-09 12:00 |
11:29:37.75 |
-76:07:54.7 |
HIP 56258 |
13.14 |
| 2026-02-10 00:00 |
11:29:31.42 |
-76:08:08.8 |
HIP 56258 |
13.20 |
| 2026-02-10 12:00 |
11:29:25.05 |
-76:08:22.6 |
HIP 56258 |
13.28 |
| 2026-02-11 00:00 |
11:29:18.65 |
-76:08:36.2 |
HIP 56258 |
13.37 |
| 2026-02-11 12:00 |
11:29:12.21 |
-76:08:49.5 |
HIP 56258 |
13.49 |
| 2026-02-12 00:00 |
11:29:05.73 |
-76:09:02.6 |
HIP 56258 |
13.62 |
| 2026-02-12 12:00 |
11:28:59.22 |
-76:09:15.4 |
HIP 56258 |
13.77 |
| 2026-02-13 00:00 |
11:28:52.67 |
-76:09:28.0 |
HIP 56258 |
13.93 |
| 2026-02-13 12:00 |
11:28:46.08 |
-76:09:40.4 |
HIP 56258 |
14.11 |
| 2026-02-14 00:00 |
11:28:39.47 |
-76:09:52.5 |
HIP 56258 |
14.31 |
| 2026-02-14 12:00 |
11:28:32.81 |
-76:10:04.4 |
HIP 56258 |
14.52 |
| 2026-02-15 00:00 |
11:28:26.13 |
-76:10:16.0 |
HIP 56258 |
14.75 |
| 2026-02-15 12:00 |
11:28:19.41 |
-76:10:27.3 |
HIP 55886 |
14.91 |
| 2026-02-16 00:00 |
11:28:12.66 |
-76:10:38.4 |
HIP 55886 |
14.99 |
| 2026-02-16 12:00 |
11:28:05.88 |
-76:10:49.3 |
HIP 55886 |
15.08 |
| 2026-02-17 00:00 |
11:27:59.07 |
-76:11:00.0 |
HIP 55886 |
15.18 |
| 2026-02-17 12:00 |
11:27:52.22 |
-76:11:10.3 |
HIP 55886 |
15.29 |
| 2026-02-18 00:00 |
11:27:45.35 |
-76:11:20.4 |
HIP 55886 |
15.40 |
| 2026-02-18 12:00 |
11:27:38.45 |
-76:11:30.2 |
HIP 55886 |
15.52 |
| 2026-02-19 00:00 |
11:27:31.52 |
-76:11:39.8 |
HIP 55886 |
15.65 |
| 2026-02-19 12:00 |
11:27:24.57 |
-76:11:49.1 |
HIP 55886 |
15.79 |
| 2026-02-20 00:00 |
11:27:17.59 |
-76:11:58.2 |
HIP 55886 |
15.93 |
| 2026-02-20 12:00 |
11:27:10.58 |
-76:12:07.0 |
HIP 55886 |
16.08 |
| 2026-02-21 00:00 |
11:27:03.55 |
-76:12:15.5 |
HIP 55886 |
16.24 |
| 2026-02-21 12:00 |
11:26:56.49 |
-76:12:23.8 |
HIP 55886 |
16.40 |
| 2026-02-22 00:00 |
11:26:49.41 |
-76:12:31.9 |
HIP 55886 |
16.57 |
| 2026-02-22 12:00 |
11:26:42.30 |
-76:12:39.6 |
HIP 55886 |
16.75 |
| 2026-02-23 00:00 |
11:26:35.17 |
-76:12:47.1 |
HIP 55886 |
16.93 |
| 2026-02-23 12:00 |
11:26:28.03 |
-76:12:54.4 |
HIP 55886 |
17.12 |
| 2026-02-24 00:00 |
11:26:20.85 |
-76:13:01.4 |
HIP 55578 |
17.13 |