| Parameter |
Value |
| Designation |
C/1984 S1 (Meier) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1984-10-13T23:45:57.159360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:31Z |
| Obs used |
12 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1984-09-23.0000000 |
| e |
0.99898032 |
| q (au) |
0.856608 |
| a (au) |
840.076952 |
| i (deg) |
145.614483 |
| Ω (om, deg) |
11.711482 |
| ω (w, deg) |
128.076601 |
| M (ma, deg) |
359.999150 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.608 + 3.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.608 |
| n |
3.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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 |
04:57:16.96 |
-07:49:14.4 |
HIP 22909 |
23.04 |
| 2026-06-01 12:00 |
04:57:18.67 |
-07:49:10.6 |
HIP 22909 |
23.47 |
| 2026-06-02 00:00 |
04:57:20.38 |
-07:49:07.0 |
HIP 22909 |
23.90 |
| 2026-06-02 12:00 |
04:57:22.09 |
-07:49:03.4 |
HIP 22909 |
24.33 |
| 2026-06-03 00:00 |
04:57:23.80 |
-07:49:00.0 |
HIP 22909 |
24.75 |
| 2026-06-03 12:00 |
04:57:25.51 |
-07:48:56.6 |
HIP 22909 |
25.18 |
| 2026-06-04 00:00 |
04:57:27.22 |
-07:48:53.4 |
HIP 22909 |
25.61 |
| 2026-06-04 12:00 |
04:57:28.94 |
-07:48:50.3 |
HIP 22909 |
26.03 |
| 2026-06-05 00:00 |
04:57:30.65 |
-07:48:47.3 |
HIP 22909 |
26.46 |
| 2026-06-05 12:00 |
04:57:32.36 |
-07:48:44.4 |
HIP 23182 |
26.25 |
| 2026-06-06 00:00 |
04:57:34.08 |
-07:48:41.7 |
HIP 23182 |
25.82 |
| 2026-06-06 12:00 |
04:57:35.79 |
-07:48:39.0 |
HIP 23182 |
25.39 |
| 2026-06-07 00:00 |
04:57:37.51 |
-07:48:36.4 |
HIP 23182 |
24.97 |
| 2026-06-07 12:00 |
04:57:39.22 |
-07:48:34.0 |
HIP 23182 |
24.54 |
| 2026-06-08 00:00 |
04:57:40.94 |
-07:48:31.7 |
HIP 23182 |
24.11 |
| 2026-06-08 12:00 |
04:57:42.65 |
-07:48:29.4 |
HIP 23182 |
23.69 |
| 2026-06-09 00:00 |
04:57:44.37 |
-07:48:27.3 |
HIP 23182 |
23.26 |
| 2026-06-09 12:00 |
04:57:46.08 |
-07:48:25.3 |
HIP 23182 |
22.84 |
| 2026-06-10 00:00 |
04:57:47.79 |
-07:48:23.5 |
HIP 23182 |
22.41 |
| 2026-06-10 12:00 |
04:57:49.51 |
-07:48:21.7 |
HIP 23182 |
21.99 |
| 2026-06-11 00:00 |
04:57:51.22 |
-07:48:20.0 |
HIP 23182 |
21.56 |
| 2026-06-11 12:00 |
04:57:52.93 |
-07:48:18.5 |
HIP 23182 |
21.14 |
| 2026-06-12 00:00 |
04:57:54.64 |
-07:48:17.1 |
HIP 23182 |
20.71 |
| 2026-06-12 12:00 |
04:57:56.35 |
-07:48:15.8 |
HIP 23182 |
20.29 |
| 2026-06-13 00:00 |
04:57:58.05 |
-07:48:14.6 |
HIP 23182 |
19.87 |
| 2026-06-13 12:00 |
04:57:59.76 |
-07:48:13.5 |
HIP 23182 |
19.44 |
| 2026-06-14 00:00 |
04:58:01.46 |
-07:48:12.5 |
HIP 23182 |
19.02 |
| 2026-06-14 12:00 |
04:58:03.16 |
-07:48:11.7 |
HIP 23182 |
18.60 |
| 2026-06-15 00:00 |
04:58:04.86 |
-07:48:10.9 |
HIP 23182 |
18.18 |
| 2026-06-15 12:00 |
04:58:06.56 |
-07:48:10.3 |
HIP 23182 |
17.76 |
| 2026-06-16 00:00 |
04:58:08.25 |
-07:48:09.8 |
HIP 23182 |
17.34 |
| 2026-06-16 12:00 |
04:58:09.95 |
-07:48:09.4 |
HIP 23182 |
16.92 |
| 2026-06-17 00:00 |
04:58:11.64 |
-07:48:09.1 |
HIP 23182 |
16.50 |
| 2026-06-17 12:00 |
04:58:13.33 |
-07:48:08.9 |
HIP 23182 |
16.09 |
| 2026-06-18 00:00 |
04:58:15.01 |
-07:48:08.9 |
HIP 23182 |
15.67 |
| 2026-06-18 12:00 |
04:58:16.70 |
-07:48:08.9 |
HIP 23182 |
15.25 |
| 2026-06-19 00:00 |
04:58:18.38 |
-07:48:09.1 |
HIP 23182 |
14.84 |
| 2026-06-19 12:00 |
04:58:20.05 |
-07:48:09.4 |
HIP 23182 |
14.43 |
| 2026-06-20 00:00 |
04:58:21.73 |
-07:48:09.8 |
HIP 23182 |
14.01 |
| 2026-06-20 12:00 |
04:58:23.40 |
-07:48:10.3 |
HIP 23182 |
13.60 |
| 2026-06-21 00:00 |
04:58:25.06 |
-07:48:10.9 |
HIP 23182 |
13.19 |
| 2026-06-21 12:00 |
04:58:26.73 |
-07:48:11.7 |
HIP 23182 |
12.78 |
| 2026-06-22 00:00 |
04:58:28.39 |
-07:48:12.5 |
HIP 23182 |
12.38 |