| Parameter |
Value |
| Designation |
C/1983 R1 (Shoemaker) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1983-11-23T19:05:28.720320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:31Z |
| Obs used |
117 |
| NEO |
- |
| M1 |
5.800 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1983-12-05.0000000 |
| e |
1.00019923 |
| q (au) |
3.344912 |
| a (au) |
-16789.101324 |
| i (deg) |
137.597258 |
| Ω (om, deg) |
164.683890 |
| ω (w, deg) |
176.039037 |
| M (ma, deg) |
0.000005 |
Magnitude
Scatter + Global Linear
$$
M_a = (4.970 + 5.968\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
4.970 |
| n |
5.968 |
| gf |
1.000 |
| gb |
-0.719 |
| 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 |
11:52:48.48 |
-20:53:12.6 |
HIP 57771 |
28.49 |
| 2026-06-01 12:00 |
11:52:47.90 |
-20:52:59.1 |
HIP 57771 |
28.42 |
| 2026-06-02 00:00 |
11:52:47.33 |
-20:52:45.6 |
HIP 57771 |
28.35 |
| 2026-06-02 12:00 |
11:52:46.78 |
-20:52:32.2 |
HIP 57771 |
28.28 |
| 2026-06-03 00:00 |
11:52:46.24 |
-20:52:18.8 |
HIP 57771 |
28.22 |
| 2026-06-03 12:00 |
11:52:45.72 |
-20:52:05.5 |
HIP 57771 |
28.17 |
| 2026-06-04 00:00 |
11:52:45.21 |
-20:51:52.3 |
HIP 57771 |
28.12 |
| 2026-06-04 12:00 |
11:52:44.72 |
-20:51:39.1 |
HIP 57771 |
28.08 |
| 2026-06-05 00:00 |
11:52:44.24 |
-20:51:26.0 |
HIP 57771 |
28.04 |
| 2026-06-05 12:00 |
11:52:43.78 |
-20:51:13.0 |
HIP 57771 |
28.00 |
| 2026-06-06 00:00 |
11:52:43.33 |
-20:51:00.0 |
HIP 57771 |
27.98 |
| 2026-06-06 12:00 |
11:52:42.89 |
-20:50:47.1 |
HIP 57771 |
27.95 |
| 2026-06-07 00:00 |
11:52:42.47 |
-20:50:34.2 |
HIP 57771 |
27.93 |
| 2026-06-07 12:00 |
11:52:42.07 |
-20:50:21.5 |
HIP 57771 |
27.92 |
| 2026-06-08 00:00 |
11:52:41.68 |
-20:50:08.8 |
HIP 57771 |
27.91 |
| 2026-06-08 12:00 |
11:52:41.30 |
-20:49:56.1 |
HIP 57771 |
27.90 |
| 2026-06-09 00:00 |
11:52:40.94 |
-20:49:43.6 |
HIP 57771 |
27.90 |
| 2026-06-09 12:00 |
11:52:40.59 |
-20:49:31.1 |
HIP 57771 |
27.91 |
| 2026-06-10 00:00 |
11:52:40.26 |
-20:49:18.6 |
HIP 57771 |
27.92 |
| 2026-06-10 12:00 |
11:52:39.95 |
-20:49:06.3 |
HIP 57771 |
27.93 |
| 2026-06-11 00:00 |
11:52:39.64 |
-20:48:54.0 |
HIP 57771 |
27.95 |
| 2026-06-11 12:00 |
11:52:39.36 |
-20:48:41.8 |
HIP 57771 |
27.97 |
| 2026-06-12 00:00 |
11:52:39.09 |
-20:48:29.7 |
HIP 57771 |
27.99 |
| 2026-06-12 12:00 |
11:52:38.83 |
-20:48:17.6 |
HIP 57771 |
28.03 |
| 2026-06-13 00:00 |
11:52:38.59 |
-20:48:05.6 |
HIP 57771 |
28.06 |
| 2026-06-13 12:00 |
11:52:38.36 |
-20:47:53.7 |
HIP 57771 |
28.10 |
| 2026-06-14 00:00 |
11:52:38.15 |
-20:47:41.9 |
HIP 57771 |
28.14 |
| 2026-06-14 12:00 |
11:52:37.95 |
-20:47:30.2 |
HIP 57771 |
28.19 |
| 2026-06-15 00:00 |
11:52:37.77 |
-20:47:18.5 |
HIP 57771 |
28.24 |
| 2026-06-15 12:00 |
11:52:37.60 |
-20:47:06.9 |
HIP 57771 |
28.29 |
| 2026-06-16 00:00 |
11:52:37.45 |
-20:46:55.5 |
HIP 57771 |
28.35 |
| 2026-06-16 12:00 |
11:52:37.31 |
-20:46:44.0 |
HIP 57771 |
28.41 |
| 2026-06-17 00:00 |
11:52:37.19 |
-20:46:32.7 |
HIP 57771 |
28.48 |
| 2026-06-17 12:00 |
11:52:37.08 |
-20:46:21.5 |
HIP 57771 |
28.54 |
| 2026-06-18 00:00 |
11:52:36.99 |
-20:46:10.3 |
HIP 57771 |
28.62 |
| 2026-06-18 12:00 |
11:52:36.91 |
-20:45:59.2 |
HIP 57986 |
28.63 |
| 2026-06-19 00:00 |
11:52:36.85 |
-20:45:48.2 |
HIP 57986 |
28.48 |
| 2026-06-19 12:00 |
11:52:36.80 |
-20:45:37.3 |
HIP 57986 |
28.33 |
| 2026-06-20 00:00 |
11:52:36.77 |
-20:45:26.5 |
HIP 57986 |
28.18 |
| 2026-06-20 12:00 |
11:52:36.75 |
-20:45:15.8 |
HIP 57986 |
28.03 |
| 2026-06-21 00:00 |
11:52:36.75 |
-20:45:05.2 |
HIP 57986 |
27.88 |
| 2026-06-21 12:00 |
11:52:36.76 |
-20:44:54.6 |
HIP 57986 |
27.72 |
| 2026-06-22 00:00 |
11:52:36.79 |
-20:44:44.2 |
HIP 57986 |
27.57 |