| 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) |
| 2026-07-29 00:00 |
01:23:53.64 |
+39:25:17.2 |
HIP 6604 |
10.62 |
| 2026-07-29 12:00 |
01:23:53.05 |
+39:25:29.3 |
HIP 6604 |
10.74 |
| 2026-07-30 00:00 |
01:23:52.44 |
+39:25:41.3 |
HIP 6604 |
10.86 |
| 2026-07-30 12:00 |
01:23:51.81 |
+39:25:53.1 |
HIP 6604 |
10.99 |
| 2026-07-31 00:00 |
01:23:51.17 |
+39:26:04.9 |
HIP 6604 |
11.13 |
| 2026-07-31 12:00 |
01:23:50.51 |
+39:26:16.5 |
HIP 6604 |
11.28 |
| 2026-08-01 00:00 |
01:23:49.83 |
+39:26:28.1 |
HIP 6604 |
11.43 |
| 2026-08-01 12:00 |
01:23:49.13 |
+39:26:39.6 |
HIP 6604 |
11.59 |
| 2026-08-02 00:00 |
01:23:48.42 |
+39:26:50.9 |
HIP 6604 |
11.75 |
| 2026-08-02 12:00 |
01:23:47.68 |
+39:27:02.2 |
HIP 6604 |
11.92 |
| 2026-08-03 00:00 |
01:23:46.93 |
+39:27:13.4 |
HIP 6604 |
12.09 |
| 2026-08-03 12:00 |
01:23:46.16 |
+39:27:24.4 |
HIP 6604 |
12.27 |
| 2026-08-04 00:00 |
01:23:45.37 |
+39:27:35.4 |
HIP 6604 |
12.46 |
| 2026-08-04 12:00 |
01:23:44.57 |
+39:27:46.2 |
HIP 6604 |
12.65 |
| 2026-08-05 00:00 |
01:23:43.75 |
+39:27:56.9 |
HIP 6604 |
12.84 |
| 2026-08-05 12:00 |
01:23:42.90 |
+39:28:07.6 |
HIP 6604 |
13.04 |
| 2026-08-06 00:00 |
01:23:42.05 |
+39:28:18.1 |
HIP 6604 |
13.24 |
| 2026-08-06 12:00 |
01:23:41.17 |
+39:28:28.5 |
HIP 6604 |
13.45 |
| 2026-08-07 00:00 |
01:23:40.27 |
+39:28:38.8 |
HIP 6604 |
13.66 |
| 2026-08-07 12:00 |
01:23:39.36 |
+39:28:49.0 |
HIP 6604 |
13.87 |
| 2026-08-08 00:00 |
01:23:38.43 |
+39:28:59.1 |
HIP 6604 |
14.09 |
| 2026-08-08 12:00 |
01:23:37.49 |
+39:29:09.0 |
HIP 6604 |
14.31 |
| 2026-08-09 00:00 |
01:23:36.52 |
+39:29:18.9 |
HIP 6604 |
14.54 |
| 2026-08-09 12:00 |
01:23:35.54 |
+39:29:28.6 |
HIP 6604 |
14.76 |
| 2026-08-10 00:00 |
01:23:34.54 |
+39:29:38.2 |
HIP 6604 |
15.00 |
| 2026-08-10 12:00 |
01:23:33.52 |
+39:29:47.7 |
HIP 6604 |
15.23 |
| 2026-08-11 00:00 |
01:23:32.49 |
+39:29:57.1 |
HIP 6604 |
15.47 |
| 2026-08-11 12:00 |
01:23:31.44 |
+39:30:06.4 |
HIP 6604 |
15.71 |
| 2026-08-12 00:00 |
01:23:30.37 |
+39:30:15.5 |
HIP 6604 |
15.95 |
| 2026-08-12 12:00 |
01:23:29.28 |
+39:30:24.6 |
HIP 6604 |
16.20 |
| 2026-08-13 00:00 |
01:23:28.18 |
+39:30:33.5 |
HIP 6604 |
16.45 |
| 2026-08-13 12:00 |
01:23:27.06 |
+39:30:42.3 |
HIP 6604 |
16.70 |
| 2026-08-14 00:00 |
01:23:25.92 |
+39:30:50.9 |
HIP 6604 |
16.96 |
| 2026-08-14 12:00 |
01:23:24.77 |
+39:30:59.5 |
HIP 6604 |
17.21 |
| 2026-08-15 00:00 |
01:23:23.60 |
+39:31:07.9 |
HIP 6604 |
17.47 |
| 2026-08-15 12:00 |
01:23:22.41 |
+39:31:16.2 |
HIP 6604 |
17.74 |
| 2026-08-16 00:00 |
01:23:21.21 |
+39:31:24.4 |
HIP 6604 |
18.00 |
| 2026-08-16 12:00 |
01:23:19.99 |
+39:31:32.4 |
HIP 6604 |
18.27 |
| 2026-08-17 00:00 |
01:23:18.75 |
+39:31:40.3 |
HIP 6604 |
18.54 |
| 2026-08-17 12:00 |
01:23:17.49 |
+39:31:48.1 |
HIP 6604 |
18.81 |
| 2026-08-18 00:00 |
01:23:16.23 |
+39:31:55.8 |
HIP 6604 |
19.09 |
| 2026-08-18 12:00 |
01:23:14.94 |
+39:32:03.4 |
HIP 6604 |
19.36 |
| 2026-08-19 00:00 |
01:23:13.64 |
+39:32:10.8 |
HIP 6604 |
19.64 |