| 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) |
| 2026-09-20 00:00 |
01:21:21.43 |
+39:35:19.9 |
HIP 6248 |
32.81 |
| 2026-09-20 12:00 |
01:21:19.31 |
+39:35:18.1 |
HIP 6248 |
32.61 |
| 2026-09-21 00:00 |
01:21:17.18 |
+39:35:16.3 |
HIP 6248 |
32.42 |
| 2026-09-21 12:00 |
01:21:15.05 |
+39:35:14.2 |
HIP 6248 |
32.22 |
| 2026-09-22 00:00 |
01:21:12.91 |
+39:35:12.1 |
HIP 6248 |
32.03 |
| 2026-09-22 12:00 |
01:21:10.75 |
+39:35:09.8 |
HIP 6248 |
31.84 |
| 2026-09-23 00:00 |
01:21:08.60 |
+39:35:07.3 |
HIP 6248 |
31.64 |
| 2026-09-23 12:00 |
01:21:06.43 |
+39:35:04.7 |
HIP 6248 |
31.46 |
| 2026-09-24 00:00 |
01:21:04.26 |
+39:35:02.0 |
HIP 6248 |
31.27 |
| 2026-09-24 12:00 |
01:21:02.08 |
+39:34:59.1 |
HIP 6248 |
31.08 |
| 2026-09-25 00:00 |
01:20:59.89 |
+39:34:56.0 |
HIP 6248 |
30.90 |
| 2026-09-25 12:00 |
01:20:57.70 |
+39:34:52.9 |
HIP 6248 |
30.72 |
| 2026-09-26 00:00 |
01:20:55.50 |
+39:34:49.5 |
HIP 6248 |
30.54 |
| 2026-09-26 12:00 |
01:20:53.29 |
+39:34:46.1 |
HIP 6248 |
30.36 |
| 2026-09-27 00:00 |
01:20:51.08 |
+39:34:42.4 |
HIP 6248 |
30.19 |
| 2026-09-27 12:00 |
01:20:48.86 |
+39:34:38.7 |
HIP 6248 |
30.01 |
| 2026-09-28 00:00 |
01:20:46.63 |
+39:34:34.8 |
HIP 6248 |
29.84 |
| 2026-09-28 12:00 |
01:20:44.40 |
+39:34:30.7 |
HIP 6248 |
29.68 |
| 2026-09-29 00:00 |
01:20:42.16 |
+39:34:26.6 |
HIP 6248 |
29.51 |
| 2026-09-29 12:00 |
01:20:39.92 |
+39:34:22.2 |
HIP 6248 |
29.35 |
| 2026-09-30 00:00 |
01:20:37.68 |
+39:34:17.7 |
HIP 6248 |
29.20 |
| 2026-09-30 12:00 |
01:20:35.42 |
+39:34:13.1 |
HIP 6248 |
29.04 |
| 2026-10-01 00:00 |
01:20:33.17 |
+39:34:08.4 |
HIP 6248 |
28.89 |
| 2026-10-01 12:00 |
01:20:30.90 |
+39:34:03.5 |
HIP 6248 |
28.74 |
| 2026-10-02 00:00 |
01:20:28.64 |
+39:33:58.4 |
HIP 6248 |
28.60 |
| 2026-10-02 12:00 |
01:20:26.36 |
+39:33:53.2 |
HIP 6248 |
28.46 |
| 2026-10-03 00:00 |
01:20:24.09 |
+39:33:47.9 |
HIP 6248 |
28.33 |
| 2026-10-03 12:00 |
01:20:21.81 |
+39:33:42.4 |
HIP 6248 |
28.20 |
| 2026-10-04 00:00 |
01:20:19.52 |
+39:33:36.8 |
HIP 6248 |
28.07 |
| 2026-10-04 12:00 |
01:20:17.23 |
+39:33:31.1 |
HIP 6248 |
27.95 |
| 2026-10-05 00:00 |
01:20:14.94 |
+39:33:25.2 |
HIP 6248 |
27.83 |
| 2026-10-05 12:00 |
01:20:12.65 |
+39:33:19.2 |
HIP 6248 |
27.71 |
| 2026-10-06 00:00 |
01:20:10.35 |
+39:33:13.0 |
HIP 6248 |
27.60 |
| 2026-10-06 12:00 |
01:20:08.04 |
+39:33:06.7 |
HIP 6248 |
27.50 |
| 2026-10-07 00:00 |
01:20:05.74 |
+39:33:00.2 |
HIP 6248 |
27.40 |
| 2026-10-07 12:00 |
01:20:03.43 |
+39:32:53.7 |
HIP 6248 |
27.31 |
| 2026-10-08 00:00 |
01:20:01.12 |
+39:32:46.9 |
HIP 6248 |
27.22 |
| 2026-10-08 12:00 |
01:19:58.81 |
+39:32:40.1 |
HIP 6248 |
27.13 |
| 2026-10-09 00:00 |
01:19:56.49 |
+39:32:33.1 |
HIP 6248 |
27.06 |
| 2026-10-09 12:00 |
01:19:54.17 |
+39:32:25.9 |
HIP 6248 |
26.98 |
| 2026-10-10 00:00 |
01:19:51.85 |
+39:32:18.7 |
HIP 6248 |
26.91 |
| 2026-10-10 12:00 |
01:19:49.53 |
+39:32:11.3 |
HIP 6248 |
26.85 |
| 2026-10-11 00:00 |
01:19:47.21 |
+39:32:03.7 |
HIP 6248 |
26.80 |