| 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) |
| 2026-05-12 00:00 |
11:10:27.06 |
-75:42:24.0 |
HIP 54852 |
13.37 |
| 2026-05-12 12:00 |
11:10:24.02 |
-75:41:57.7 |
HIP 54852 |
13.72 |
| 2026-05-13 00:00 |
11:10:21.04 |
-75:41:31.4 |
HIP 54852 |
14.07 |
| 2026-05-13 12:00 |
11:10:18.12 |
-75:41:05.0 |
HIP 54852 |
14.42 |
| 2026-05-14 00:00 |
11:10:15.25 |
-75:40:38.5 |
HIP 54852 |
14.78 |
| 2026-05-14 12:00 |
11:10:12.45 |
-75:40:12.0 |
HIP 54852 |
15.15 |
| 2026-05-15 00:00 |
11:10:09.71 |
-75:39:45.3 |
HIP 54852 |
15.51 |
| 2026-05-15 12:00 |
11:10:07.03 |
-75:39:18.5 |
HIP 54852 |
15.88 |
| 2026-05-16 00:00 |
11:10:04.41 |
-75:38:51.7 |
HIP 54852 |
16.26 |
| 2026-05-16 12:00 |
11:10:01.85 |
-75:38:24.8 |
HIP 54852 |
16.63 |
| 2026-05-17 00:00 |
11:09:59.35 |
-75:37:57.8 |
HIP 54852 |
17.01 |
| 2026-05-17 12:00 |
11:09:56.91 |
-75:37:30.8 |
HIP 54852 |
17.39 |
| 2026-05-18 00:00 |
11:09:54.53 |
-75:37:03.6 |
HIP 54852 |
17.78 |
| 2026-05-18 12:00 |
11:09:52.21 |
-75:36:36.4 |
HIP 54852 |
18.16 |
| 2026-05-19 00:00 |
11:09:49.95 |
-75:36:09.2 |
HIP 54852 |
18.55 |
| 2026-05-19 12:00 |
11:09:47.76 |
-75:35:41.8 |
HIP 54852 |
18.94 |
| 2026-05-20 00:00 |
11:09:45.62 |
-75:35:14.5 |
HIP 54852 |
19.33 |
| 2026-05-20 12:00 |
11:09:43.55 |
-75:34:47.0 |
HIP 54852 |
19.72 |
| 2026-05-21 00:00 |
11:09:41.53 |
-75:34:19.5 |
HIP 54852 |
20.12 |
| 2026-05-21 12:00 |
11:09:39.58 |
-75:33:51.9 |
HIP 54852 |
20.51 |
| 2026-05-22 00:00 |
11:09:37.69 |
-75:33:24.3 |
HIP 54852 |
20.91 |
| 2026-05-22 12:00 |
11:09:35.86 |
-75:32:56.7 |
HIP 54852 |
21.31 |
| 2026-05-23 00:00 |
11:09:34.09 |
-75:32:28.9 |
HIP 54852 |
21.71 |
| 2026-05-23 12:00 |
11:09:32.38 |
-75:32:01.2 |
HIP 54852 |
22.11 |
| 2026-05-24 00:00 |
11:09:30.74 |
-75:31:33.4 |
HIP 54852 |
22.51 |
| 2026-05-24 12:00 |
11:09:29.15 |
-75:31:05.5 |
HIP 54852 |
22.91 |
| 2026-05-25 00:00 |
11:09:27.63 |
-75:30:37.7 |
HIP 54263 |
22.80 |
| 2026-05-25 12:00 |
11:09:26.16 |
-75:30:09.7 |
HIP 54263 |
22.37 |
| 2026-05-26 00:00 |
11:09:24.76 |
-75:29:41.8 |
HIP 54263 |
21.94 |
| 2026-05-26 12:00 |
11:09:23.42 |
-75:29:13.8 |
HIP 54263 |
21.51 |
| 2026-05-27 00:00 |
11:09:22.14 |
-75:28:45.8 |
HIP 54263 |
21.09 |
| 2026-05-27 12:00 |
11:09:20.92 |
-75:28:17.7 |
HIP 54263 |
20.67 |
| 2026-05-28 00:00 |
11:09:19.76 |
-75:27:49.6 |
HIP 54263 |
20.25 |
| 2026-05-28 12:00 |
11:09:18.66 |
-75:27:21.5 |
HIP 54263 |
19.84 |
| 2026-05-29 00:00 |
11:09:17.62 |
-75:26:53.4 |
HIP 54263 |
19.43 |
| 2026-05-29 12:00 |
11:09:16.65 |
-75:26:25.3 |
HIP 54263 |
19.03 |
| 2026-05-30 00:00 |
11:09:15.73 |
-75:25:57.1 |
HIP 54263 |
18.64 |
| 2026-05-30 12:00 |
11:09:14.87 |
-75:25:28.9 |
HIP 54263 |
18.25 |
| 2026-05-31 00:00 |
11:09:14.08 |
-75:25:00.7 |
HIP 54263 |
17.87 |
| 2026-05-31 12:00 |
11:09:13.35 |
-75:24:32.5 |
HIP 54263 |
17.49 |
| 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 |