| Parameter |
Value |
| Designation |
C/2017 K6 (Jacques) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-01-03T03:16:30.506880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:34Z |
| Obs used |
475 |
| NEO |
- |
| M1 |
12.100 |
| K1 |
6.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-02-05.0000000 |
| e |
0.99822114 |
| q (au) |
2.002756 |
| a (au) |
1125.867222 |
| i (deg) |
57.251183 |
| Ω (om, deg) |
85.054187 |
| ω (w, deg) |
303.838384 |
| M (ma, deg) |
0.000857 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.455 + 4.414\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.455 |
| n |
4.414 |
| gf |
1.000 |
| gb |
-0.891 |
| k |
0.984 |
| 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 |
| 2017-05-29 |
2017-09-21 |
-1.7758 |
+1.105 |
| 2017-09-21 |
2017-12-30 |
+16.2248 |
-5.376 |
| 2018-01-05 |
2019-02-14 |
+1.6842 |
-1.364 |
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 |
13:32:56.91 |
+55:19:10.4 |
HIP 66130 |
8.43 |
| 2026-06-01 12:00 |
13:32:51.38 |
+55:18:21.4 |
HIP 66130 |
8.15 |
| 2026-06-02 00:00 |
13:32:45.92 |
+55:17:32.0 |
HIP 66130 |
8.01 |
| 2026-06-02 12:00 |
13:32:40.52 |
+55:16:42.0 |
HIP 66130 |
8.01 |
| 2026-06-03 00:00 |
13:32:35.18 |
+55:15:51.6 |
HIP 66130 |
8.17 |
| 2026-06-03 12:00 |
13:32:29.90 |
+55:15:00.6 |
HIP 66130 |
8.46 |
| 2026-06-04 00:00 |
13:32:24.69 |
+55:14:09.2 |
HIP 66130 |
8.89 |
| 2026-06-04 12:00 |
13:32:19.54 |
+55:13:17.3 |
HIP 66130 |
9.41 |
| 2026-06-05 00:00 |
13:32:14.45 |
+55:12:24.9 |
HIP 66130 |
10.04 |
| 2026-06-05 12:00 |
13:32:09.42 |
+55:11:32.1 |
HIP 66130 |
10.73 |
| 2026-06-06 00:00 |
13:32:04.46 |
+55:10:38.8 |
HIP 66130 |
11.49 |
| 2026-06-06 12:00 |
13:31:59.57 |
+55:09:45.0 |
HIP 66130 |
12.30 |
| 2026-06-07 00:00 |
13:31:54.74 |
+55:08:50.8 |
HIP 66130 |
13.15 |
| 2026-06-07 12:00 |
13:31:49.97 |
+55:07:56.1 |
HIP 65960 |
13.07 |
| 2026-06-08 00:00 |
13:31:45.27 |
+55:07:00.9 |
HIP 65960 |
12.02 |
| 2026-06-08 12:00 |
13:31:40.64 |
+55:06:05.3 |
HIP 65960 |
10.98 |
| 2026-06-09 00:00 |
13:31:36.07 |
+55:05:09.3 |
HIP 65960 |
9.95 |
| 2026-06-09 12:00 |
13:31:31.57 |
+55:04:12.8 |
HIP 65960 |
8.95 |
| 2026-06-10 00:00 |
13:31:27.13 |
+55:03:15.9 |
HIP 65960 |
7.97 |
| 2026-06-10 12:00 |
13:31:22.76 |
+55:02:18.6 |
HIP 65960 |
7.04 |
| 2026-06-11 00:00 |
13:31:18.46 |
+55:01:20.8 |
HIP 65960 |
6.17 |
| 2026-06-11 12:00 |
13:31:14.22 |
+55:00:22.6 |
HIP 65960 |
5.39 |
| 2026-06-12 00:00 |
13:31:10.06 |
+54:59:24.1 |
HIP 65960 |
4.75 |
| 2026-06-12 12:00 |
13:31:05.96 |
+54:58:25.0 |
HIP 65960 |
4.32 |
| 2026-06-13 00:00 |
13:31:01.93 |
+54:57:25.6 |
HIP 65960 |
4.15 |
| 2026-06-13 12:00 |
13:30:57.97 |
+54:56:25.8 |
HIP 65960 |
4.28 |
| 2026-06-14 00:00 |
13:30:54.07 |
+54:55:25.6 |
HIP 65960 |
4.69 |
| 2026-06-14 12:00 |
13:30:50.25 |
+54:54:25.0 |
HIP 65960 |
5.31 |
| 2026-06-15 00:00 |
13:30:46.50 |
+54:53:24.0 |
HIP 65960 |
6.08 |
| 2026-06-15 12:00 |
13:30:42.81 |
+54:52:22.6 |
HIP 65960 |
6.95 |
| 2026-06-16 00:00 |
13:30:39.20 |
+54:51:20.8 |
HIP 65960 |
7.89 |
| 2026-06-16 12:00 |
13:30:35.65 |
+54:50:18.7 |
HIP 65960 |
8.87 |
| 2026-06-17 00:00 |
13:30:32.18 |
+54:49:16.2 |
HIP 65960 |
9.89 |
| 2026-06-17 12:00 |
13:30:28.77 |
+54:48:13.3 |
HIP 65960 |
10.93 |
| 2026-06-18 00:00 |
13:30:25.44 |
+54:47:10.1 |
HIP 65960 |
11.99 |
| 2026-06-18 12:00 |
13:30:22.18 |
+54:46:06.6 |
HIP 65960 |
13.06 |
| 2026-06-19 00:00 |
13:30:18.99 |
+54:45:02.6 |
HIP 65960 |
14.15 |
| 2026-06-19 12:00 |
13:30:15.87 |
+54:43:58.4 |
HIP 65960 |
15.24 |
| 2026-06-20 00:00 |
13:30:12.82 |
+54:42:53.8 |
HIP 65960 |
16.34 |
| 2026-06-20 12:00 |
13:30:09.84 |
+54:41:48.9 |
HIP 65960 |
17.44 |
| 2026-06-21 00:00 |
13:30:06.93 |
+54:40:43.6 |
HIP 65960 |
18.56 |
| 2026-06-21 12:00 |
13:30:04.09 |
+54:39:38.1 |
HIP 65960 |
19.67 |
| 2026-06-22 00:00 |
13:30:01.33 |
+54:38:32.2 |
HIP 65960 |
20.79 |