| 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) |
| 2026-06-01 00:00 |
11:09:12.67 |
-75:24:04.3 |
HIP 54263 |
17.12 |
| 2026-06-01 12:00 |
11:09:12.06 |
-75:23:36.1 |
HIP 54263 |
16.76 |
| 2026-06-02 00:00 |
11:09:11.50 |
-75:23:07.9 |
HIP 54263 |
16.41 |
| 2026-06-02 12:00 |
11:09:11.01 |
-75:22:39.6 |
HIP 54263 |
16.07 |
| 2026-06-03 00:00 |
11:09:10.58 |
-75:22:11.4 |
HIP 54263 |
15.73 |
| 2026-06-03 12:00 |
11:09:10.21 |
-75:21:43.1 |
HIP 54263 |
15.41 |
| 2026-06-04 00:00 |
11:09:09.89 |
-75:21:14.9 |
HIP 54263 |
15.10 |
| 2026-06-04 12:00 |
11:09:09.64 |
-75:20:46.6 |
HIP 54263 |
14.80 |
| 2026-06-05 00:00 |
11:09:09.45 |
-75:20:18.4 |
HIP 54263 |
14.51 |
| 2026-06-05 12:00 |
11:09:09.32 |
-75:19:50.2 |
HIP 54263 |
14.23 |
| 2026-06-06 00:00 |
11:09:09.24 |
-75:19:22.0 |
HIP 54263 |
13.97 |
| 2026-06-06 12:00 |
11:09:09.23 |
-75:18:53.8 |
HIP 54263 |
13.72 |
| 2026-06-07 00:00 |
11:09:09.28 |
-75:18:25.6 |
HIP 54263 |
13.48 |
| 2026-06-07 12:00 |
11:09:09.38 |
-75:17:57.4 |
HIP 54263 |
13.27 |
| 2026-06-08 00:00 |
11:09:09.55 |
-75:17:29.2 |
HIP 54263 |
13.07 |
| 2026-06-08 12:00 |
11:09:09.78 |
-75:17:01.1 |
HIP 54263 |
12.88 |
| 2026-06-09 00:00 |
11:09:10.06 |
-75:16:33.0 |
HIP 54263 |
12.72 |
| 2026-06-09 12:00 |
11:09:10.41 |
-75:16:04.9 |
HIP 54263 |
12.57 |
| 2026-06-10 00:00 |
11:09:10.81 |
-75:15:36.8 |
HIP 54263 |
12.45 |
| 2026-06-10 12:00 |
11:09:11.27 |
-75:15:08.7 |
HIP 54263 |
12.34 |
| 2026-06-11 00:00 |
11:09:11.79 |
-75:14:40.7 |
HIP 54263 |
12.26 |
| 2026-06-11 12:00 |
11:09:12.37 |
-75:14:12.7 |
HIP 54263 |
12.19 |
| 2026-06-12 00:00 |
11:09:13.01 |
-75:13:44.8 |
HIP 54263 |
12.15 |
| 2026-06-12 12:00 |
11:09:13.71 |
-75:13:16.9 |
HIP 54263 |
12.13 |
| 2026-06-13 00:00 |
11:09:14.47 |
-75:12:49.0 |
HIP 54263 |
12.13 |
| 2026-06-13 12:00 |
11:09:15.28 |
-75:12:21.2 |
HIP 54263 |
12.16 |
| 2026-06-14 00:00 |
11:09:16.16 |
-75:11:53.4 |
HIP 54263 |
12.20 |
| 2026-06-14 12:00 |
11:09:17.09 |
-75:11:25.6 |
HIP 54263 |
12.27 |
| 2026-06-15 00:00 |
11:09:18.08 |
-75:10:57.9 |
HIP 54263 |
12.36 |
| 2026-06-15 12:00 |
11:09:19.13 |
-75:10:30.3 |
HIP 54263 |
12.46 |
| 2026-06-16 00:00 |
11:09:20.23 |
-75:10:02.7 |
HIP 54263 |
12.59 |
| 2026-06-16 12:00 |
11:09:21.40 |
-75:09:35.1 |
HIP 54263 |
12.74 |
| 2026-06-17 00:00 |
11:09:22.62 |
-75:09:07.6 |
HIP 54263 |
12.90 |
| 2026-06-17 12:00 |
11:09:23.90 |
-75:08:40.2 |
HIP 54263 |
13.09 |
| 2026-06-18 00:00 |
11:09:25.23 |
-75:08:12.8 |
HIP 54263 |
13.29 |
| 2026-06-18 12:00 |
11:09:26.62 |
-75:07:45.5 |
HIP 54263 |
13.50 |
| 2026-06-19 00:00 |
11:09:28.07 |
-75:07:18.2 |
HIP 54263 |
13.74 |
| 2026-06-19 12:00 |
11:09:29.57 |
-75:06:51.1 |
HIP 54263 |
13.98 |
| 2026-06-20 00:00 |
11:09:31.13 |
-75:06:23.9 |
HIP 54263 |
14.24 |
| 2026-06-20 12:00 |
11:09:32.75 |
-75:05:56.9 |
HIP 54263 |
14.52 |
| 2026-06-21 00:00 |
11:09:34.42 |
-75:05:29.9 |
HIP 54263 |
14.80 |
| 2026-06-21 12:00 |
11:09:36.15 |
-75:05:03.0 |
HIP 54263 |
15.10 |
| 2026-06-22 00:00 |
11:09:37.93 |
-75:04:36.2 |
HIP 54263 |
15.41 |