| 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) |
| 2026-06-01 00:00 |
01:23:00.74 |
+38:55:19.0 |
HIP 6578 |
18.57 |
| 2026-06-01 12:00 |
01:23:02.13 |
+38:55:35.6 |
HIP 6578 |
18.23 |
| 2026-06-02 00:00 |
01:23:03.50 |
+38:55:52.1 |
HIP 6578 |
17.89 |
| 2026-06-02 12:00 |
01:23:04.86 |
+38:56:08.7 |
HIP 6578 |
17.55 |
| 2026-06-03 00:00 |
01:23:06.21 |
+38:56:25.3 |
HIP 6578 |
17.22 |
| 2026-06-03 12:00 |
01:23:07.54 |
+38:56:42.0 |
HIP 6578 |
16.89 |
| 2026-06-04 00:00 |
01:23:08.86 |
+38:56:58.6 |
HIP 6578 |
16.56 |
| 2026-06-04 12:00 |
01:23:10.16 |
+38:57:15.3 |
HIP 6578 |
16.25 |
| 2026-06-05 00:00 |
01:23:11.45 |
+38:57:32.0 |
HIP 6578 |
15.93 |
| 2026-06-05 12:00 |
01:23:12.73 |
+38:57:48.7 |
HIP 6578 |
15.62 |
| 2026-06-06 00:00 |
01:23:13.99 |
+38:58:05.4 |
HIP 6578 |
15.32 |
| 2026-06-06 12:00 |
01:23:15.24 |
+38:58:22.1 |
HIP 6578 |
15.02 |
| 2026-06-07 00:00 |
01:23:16.47 |
+38:58:38.9 |
HIP 6578 |
14.73 |
| 2026-06-07 12:00 |
01:23:17.69 |
+38:58:55.6 |
HIP 6578 |
14.45 |
| 2026-06-08 00:00 |
01:23:18.90 |
+38:59:12.4 |
HIP 6575 |
14.13 |
| 2026-06-08 12:00 |
01:23:20.09 |
+38:59:29.2 |
HIP 6575 |
13.82 |
| 2026-06-09 00:00 |
01:23:21.27 |
+38:59:46.0 |
HIP 6575 |
13.52 |
| 2026-06-09 12:00 |
01:23:22.43 |
+39:00:02.8 |
HIP 6575 |
13.23 |
| 2026-06-10 00:00 |
01:23:23.58 |
+39:00:19.5 |
HIP 6575 |
12.94 |
| 2026-06-10 12:00 |
01:23:24.71 |
+39:00:36.3 |
HIP 6575 |
12.65 |
| 2026-06-11 00:00 |
01:23:25.83 |
+39:00:53.2 |
HIP 6575 |
12.37 |
| 2026-06-11 12:00 |
01:23:26.93 |
+39:01:10.0 |
HIP 6575 |
12.10 |
| 2026-06-12 00:00 |
01:23:28.01 |
+39:01:26.8 |
HIP 6575 |
11.84 |
| 2026-06-12 12:00 |
01:23:29.08 |
+39:01:43.6 |
HIP 6575 |
11.58 |
| 2026-06-13 00:00 |
01:23:30.14 |
+39:02:00.4 |
HIP 6575 |
11.33 |
| 2026-06-13 12:00 |
01:23:31.18 |
+39:02:17.2 |
HIP 6575 |
11.09 |
| 2026-06-14 00:00 |
01:23:32.21 |
+39:02:34.0 |
HIP 6575 |
10.86 |
| 2026-06-14 12:00 |
01:23:33.21 |
+39:02:50.8 |
HIP 6575 |
10.64 |
| 2026-06-15 00:00 |
01:23:34.21 |
+39:03:07.6 |
HIP 6575 |
10.43 |
| 2026-06-15 12:00 |
01:23:35.18 |
+39:03:24.4 |
HIP 6575 |
10.23 |
| 2026-06-16 00:00 |
01:23:36.15 |
+39:03:41.2 |
HIP 6575 |
10.04 |
| 2026-06-16 12:00 |
01:23:37.09 |
+39:03:57.9 |
HIP 6575 |
9.85 |
| 2026-06-17 00:00 |
01:23:38.02 |
+39:04:14.7 |
HIP 6575 |
9.68 |
| 2026-06-17 12:00 |
01:23:38.93 |
+39:04:31.4 |
HIP 6575 |
9.53 |
| 2026-06-18 00:00 |
01:23:39.83 |
+39:04:48.2 |
HIP 6575 |
9.38 |
| 2026-06-18 12:00 |
01:23:40.71 |
+39:05:04.9 |
HIP 6575 |
9.25 |
| 2026-06-19 00:00 |
01:23:41.57 |
+39:05:21.6 |
HIP 6575 |
9.13 |
| 2026-06-19 12:00 |
01:23:42.42 |
+39:05:38.3 |
HIP 6575 |
9.02 |
| 2026-06-20 00:00 |
01:23:43.25 |
+39:05:54.9 |
HIP 6575 |
8.93 |
| 2026-06-20 12:00 |
01:23:44.07 |
+39:06:11.6 |
HIP 6575 |
8.85 |
| 2026-06-21 00:00 |
01:23:44.86 |
+39:06:28.2 |
HIP 6575 |
8.78 |
| 2026-06-21 12:00 |
01:23:45.65 |
+39:06:44.9 |
HIP 6575 |
8.73 |
| 2026-06-22 00:00 |
01:23:46.41 |
+39:07:01.4 |
HIP 6575 |
8.69 |