| 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) |
| 2026-03-26 00:00 |
01:18:44.40 |
+38:28:24.2 |
HIP 5982 |
21.02 |
| 2026-03-26 12:00 |
01:18:46.43 |
+38:28:29.3 |
HIP 5982 |
21.42 |
| 2026-03-27 00:00 |
01:18:48.45 |
+38:28:34.6 |
HIP 5982 |
21.82 |
| 2026-03-27 12:00 |
01:18:50.48 |
+38:28:40.0 |
HIP 6278 |
21.87 |
| 2026-03-28 00:00 |
01:18:52.52 |
+38:28:45.5 |
HIP 6278 |
21.54 |
| 2026-03-28 12:00 |
01:18:54.55 |
+38:28:51.1 |
HIP 6278 |
21.21 |
| 2026-03-29 00:00 |
01:18:56.60 |
+38:28:56.9 |
HIP 6278 |
20.89 |
| 2026-03-29 12:00 |
01:18:58.64 |
+38:29:02.8 |
HIP 6278 |
20.57 |
| 2026-03-30 00:00 |
01:19:00.70 |
+38:29:08.9 |
HIP 6278 |
20.26 |
| 2026-03-30 12:00 |
01:19:02.75 |
+38:29:15.0 |
HIP 6278 |
19.95 |
| 2026-03-31 00:00 |
01:19:04.81 |
+38:29:21.3 |
HIP 6278 |
19.64 |
| 2026-03-31 12:00 |
01:19:06.87 |
+38:29:27.8 |
HIP 6278 |
19.34 |
| 2026-04-01 00:00 |
01:19:08.94 |
+38:29:34.3 |
HIP 6278 |
19.04 |
| 2026-04-01 12:00 |
01:19:11.00 |
+38:29:41.0 |
HIP 6278 |
18.75 |
| 2026-04-02 00:00 |
01:19:13.08 |
+38:29:47.8 |
HIP 6278 |
18.46 |
| 2026-04-02 12:00 |
01:19:15.15 |
+38:29:54.7 |
HIP 6278 |
18.18 |
| 2026-04-03 00:00 |
01:19:17.23 |
+38:30:01.8 |
HIP 6278 |
17.91 |
| 2026-04-03 12:00 |
01:19:19.31 |
+38:30:09.0 |
HIP 6278 |
17.64 |
| 2026-04-04 00:00 |
01:19:21.39 |
+38:30:16.3 |
HIP 6278 |
17.38 |
| 2026-04-04 12:00 |
01:19:23.47 |
+38:30:23.7 |
HIP 6278 |
17.13 |
| 2026-04-05 00:00 |
01:19:25.56 |
+38:30:31.3 |
HIP 6278 |
16.89 |
| 2026-04-05 12:00 |
01:19:27.65 |
+38:30:39.0 |
HIP 6278 |
16.65 |
| 2026-04-06 00:00 |
01:19:29.74 |
+38:30:46.8 |
HIP 6278 |
16.42 |
| 2026-04-06 12:00 |
01:19:31.83 |
+38:30:54.7 |
HIP 6278 |
16.20 |
| 2026-04-07 00:00 |
01:19:33.93 |
+38:31:02.8 |
HIP 6278 |
16.00 |
| 2026-04-07 12:00 |
01:19:36.02 |
+38:31:10.9 |
HIP 6278 |
15.80 |
| 2026-04-08 00:00 |
01:19:38.12 |
+38:31:19.2 |
HIP 6278 |
15.61 |
| 2026-04-08 12:00 |
01:19:40.22 |
+38:31:27.6 |
HIP 6278 |
15.43 |
| 2026-04-09 00:00 |
01:19:42.32 |
+38:31:36.2 |
HIP 6278 |
15.27 |
| 2026-04-09 12:00 |
01:19:44.42 |
+38:31:44.8 |
HIP 6278 |
15.12 |
| 2026-04-10 00:00 |
01:19:46.52 |
+38:31:53.6 |
HIP 6278 |
14.98 |
| 2026-04-10 12:00 |
01:19:48.62 |
+38:32:02.5 |
HIP 6278 |
14.85 |
| 2026-04-11 00:00 |
01:19:50.72 |
+38:32:11.5 |
HIP 6278 |
14.74 |
| 2026-04-11 12:00 |
01:19:52.83 |
+38:32:20.6 |
HIP 6278 |
14.64 |
| 2026-04-12 00:00 |
01:19:54.93 |
+38:32:29.8 |
HIP 6278 |
14.56 |
| 2026-04-12 12:00 |
01:19:57.03 |
+38:32:39.2 |
HIP 6278 |
14.49 |
| 2026-04-13 00:00 |
01:19:59.13 |
+38:32:48.7 |
HIP 6278 |
14.43 |
| 2026-04-13 12:00 |
01:20:01.23 |
+38:32:58.3 |
HIP 6278 |
14.39 |
| 2026-04-14 00:00 |
01:20:03.34 |
+38:33:07.9 |
HIP 6278 |
14.37 |
| 2026-04-14 12:00 |
01:20:05.44 |
+38:33:17.8 |
HIP 6278 |
14.36 |
| 2026-04-15 00:00 |
01:20:07.54 |
+38:33:27.7 |
HIP 6278 |
14.36 |
| 2026-04-15 12:00 |
01:20:09.64 |
+38:33:37.7 |
HIP 6278 |
14.38 |
| 2026-04-16 00:00 |
01:20:11.73 |
+38:33:47.9 |
HIP 6278 |
14.42 |