C/1984 K1 (Shoemaker)
| Parameter |
Value |
| Designation |
C/1984 K1 (Shoemaker) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1985-09-04T14:13:51.985920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:31Z |
| Obs used |
176 |
| NEO |
- |
| M1 |
5.600 |
| K1 |
8.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1986-02-09.0000000 |
| e |
1.00072275 |
| q (au) |
2.696507 |
| a (au) |
-3730.894921 |
| i (deg) |
116.665429 |
| Ω (om, deg) |
49.690085 |
| ω (w, deg) |
235.469697 |
| M (ma, deg) |
0.000681 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.496 + 3.683\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.496 |
| n |
3.683 |
| gf |
1.000 |
| gb |
-0.707 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1984-05-27 |
1985-06-23 |
+0.0410 |
-0.115 |
| 1985-10-13 |
1992-01-04 |
-0.7996 |
+1.135 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
01:16:09.73 |
+38:31:58.6 |
HIP 5874 |
9.04 |
| 2026-02-03 12:00 |
01:16:10.53 |
+38:31:49.5 |
HIP 5874 |
9.14 |
| 2026-02-04 00:00 |
01:16:11.35 |
+38:31:40.6 |
HIP 5874 |
9.26 |
| 2026-02-04 12:00 |
01:16:12.19 |
+38:31:31.8 |
HIP 5874 |
9.38 |
| 2026-02-05 00:00 |
01:16:13.05 |
+38:31:23.1 |
HIP 5981 |
9.19 |
| 2026-02-05 12:00 |
01:16:13.93 |
+38:31:14.6 |
HIP 5981 |
8.98 |
| 2026-02-06 00:00 |
01:16:14.82 |
+38:31:06.2 |
HIP 5981 |
8.77 |
| 2026-02-06 12:00 |
01:16:15.73 |
+38:30:57.9 |
HIP 5981 |
8.55 |
| 2026-02-07 00:00 |
01:16:16.65 |
+38:30:49.7 |
HIP 5981 |
8.33 |
| 2026-02-07 12:00 |
01:16:17.60 |
+38:30:41.7 |
HIP 5981 |
8.11 |
| 2026-02-08 00:00 |
01:16:18.56 |
+38:30:33.8 |
HIP 5981 |
7.89 |
| 2026-02-08 12:00 |
01:16:19.54 |
+38:30:26.0 |
HIP 5981 |
7.67 |
| 2026-02-09 00:00 |
01:16:20.53 |
+38:30:18.4 |
HIP 5981 |
7.44 |
| 2026-02-09 12:00 |
01:16:21.54 |
+38:30:10.9 |
HIP 5981 |
7.21 |
| 2026-02-10 00:00 |
01:16:22.57 |
+38:30:03.5 |
HIP 5981 |
6.98 |
| 2026-02-10 12:00 |
01:16:23.61 |
+38:29:56.3 |
HIP 5981 |
6.75 |
| 2026-02-11 00:00 |
01:16:24.67 |
+38:29:49.2 |
HIP 5981 |
6.52 |
| 2026-02-11 12:00 |
01:16:25.75 |
+38:29:42.2 |
HIP 5981 |
6.28 |
| 2026-02-12 00:00 |
01:16:26.84 |
+38:29:35.4 |
HIP 5981 |
6.04 |
| 2026-02-12 12:00 |
01:16:27.95 |
+38:29:28.7 |
HIP 5981 |
5.80 |
| 2026-02-13 00:00 |
01:16:29.07 |
+38:29:22.1 |
HIP 5981 |
5.56 |
| 2026-02-13 12:00 |
01:16:30.21 |
+38:29:15.7 |
HIP 5981 |
5.32 |
| 2026-02-14 00:00 |
01:16:31.37 |
+38:29:09.4 |
HIP 5981 |
5.07 |
| 2026-02-14 12:00 |
01:16:32.54 |
+38:29:03.2 |
HIP 5981 |
4.82 |
| 2026-02-15 00:00 |
01:16:33.73 |
+38:28:57.2 |
HIP 5981 |
4.57 |
| 2026-02-15 12:00 |
01:16:34.94 |
+38:28:51.3 |
HIP 5981 |
4.32 |
| 2026-02-16 00:00 |
01:16:36.15 |
+38:28:45.6 |
HIP 5981 |
4.07 |
| 2026-02-16 12:00 |
01:16:37.39 |
+38:28:40.0 |
HIP 5981 |
3.81 |
| 2026-02-17 00:00 |
01:16:38.64 |
+38:28:34.5 |
HIP 5981 |
3.55 |
| 2026-02-17 12:00 |
01:16:39.90 |
+38:28:29.2 |
HIP 5981 |
3.29 |
| 2026-02-18 00:00 |
01:16:41.18 |
+38:28:24.0 |
HIP 5981 |
3.03 |
| 2026-02-18 12:00 |
01:16:42.48 |
+38:28:19.0 |
HIP 5981 |
2.76 |
| 2026-02-19 00:00 |
01:16:43.79 |
+38:28:14.0 |
HIP 5981 |
2.50 |
| 2026-02-19 12:00 |
01:16:45.11 |
+38:28:09.3 |
HIP 5981 |
2.23 |
| 2026-02-20 00:00 |
01:16:46.45 |
+38:28:04.7 |
HIP 5981 |
1.96 |
| 2026-02-20 12:00 |
01:16:47.80 |
+38:28:00.2 |
HIP 5981 |
1.69 |
| 2026-02-21 00:00 |
01:16:49.17 |
+38:27:55.8 |
HIP 5981 |
1.41 |
| 2026-02-21 12:00 |
01:16:50.55 |
+38:27:51.7 |
HIP 5981 |
1.14 |
| 2026-02-22 00:00 |
01:16:51.95 |
+38:27:47.6 |
HIP 5981 |
0.87 |
| 2026-02-22 12:00 |
01:16:53.36 |
+38:27:43.7 |
HIP 5981 |
0.60 |
| 2026-02-23 00:00 |
01:16:54.78 |
+38:27:39.9 |
HIP 5981 |
0.35 |
| 2026-02-23 12:00 |
01:16:56.22 |
+38:27:36.3 |
HIP 5982 |
0.17 |
| 2026-02-24 00:00 |
01:16:57.67 |
+38:27:32.8 |
HIP 5982 |
0.15 |