| Parameter |
Value |
| Designation |
C/2017 S6 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-02-26T22:22:53.693760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:35Z |
| Obs used |
247 |
| NEO |
- |
| M1 |
15.300 |
| K1 |
4.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-11-15.0000000 |
| e |
1.00140730 |
| q (au) |
1.542930 |
| a (au) |
-1096.375698 |
| i (deg) |
152.826812 |
| Ω (om, deg) |
130.873122 |
| ω (w, deg) |
134.685410 |
| M (ma, deg) |
-0.002822 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.010 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.010 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.676 |
| 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 |
| 2017-02-16 |
2017-10-28 |
+4.8973 |
-2.493 |
| 2017-10-28 |
2018-02-05 |
+7.2164 |
-2.343 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
12:43:09.37 |
-34:38:44.8 |
HIP 62037 |
21.13 |
| 2026-05-12 12:00 |
12:43:04.01 |
-34:37:51.6 |
HIP 62037 |
20.15 |
| 2026-05-13 00:00 |
12:42:58.68 |
-34:36:58.4 |
HIP 62037 |
19.22 |
| 2026-05-13 12:00 |
12:42:53.39 |
-34:36:05.0 |
HIP 62037 |
18.35 |
| 2026-05-14 00:00 |
12:42:48.14 |
-34:35:11.5 |
HIP 62037 |
17.54 |
| 2026-05-14 12:00 |
12:42:42.94 |
-34:34:18.0 |
HIP 62037 |
16.81 |
| 2026-05-15 00:00 |
12:42:37.77 |
-34:33:24.3 |
HIP 62037 |
16.17 |
| 2026-05-15 12:00 |
12:42:32.64 |
-34:32:30.6 |
HIP 62037 |
15.62 |
| 2026-05-16 00:00 |
12:42:27.56 |
-34:31:36.8 |
HIP 62037 |
15.17 |
| 2026-05-16 12:00 |
12:42:22.52 |
-34:30:42.9 |
HIP 62037 |
14.83 |
| 2026-05-17 00:00 |
12:42:17.52 |
-34:29:48.9 |
HIP 62037 |
14.60 |
| 2026-05-17 12:00 |
12:42:12.56 |
-34:28:54.9 |
HIP 62037 |
14.50 |
| 2026-05-18 00:00 |
12:42:07.65 |
-34:28:00.8 |
HIP 62037 |
14.52 |
| 2026-05-18 12:00 |
12:42:02.77 |
-34:27:06.7 |
HIP 62037 |
14.66 |
| 2026-05-19 00:00 |
12:41:57.95 |
-34:26:12.5 |
HIP 62037 |
14.91 |
| 2026-05-19 12:00 |
12:41:53.16 |
-34:25:18.3 |
HIP 62037 |
15.26 |
| 2026-05-20 00:00 |
12:41:48.42 |
-34:24:24.0 |
HIP 62037 |
15.72 |
| 2026-05-20 12:00 |
12:41:43.73 |
-34:23:29.7 |
HIP 62037 |
16.26 |
| 2026-05-21 00:00 |
12:41:39.08 |
-34:22:35.3 |
HIP 62037 |
16.88 |
| 2026-05-21 12:00 |
12:41:34.47 |
-34:21:40.9 |
HIP 62037 |
17.58 |
| 2026-05-22 00:00 |
12:41:29.91 |
-34:20:46.5 |
HIP 62037 |
18.32 |
| 2026-05-22 12:00 |
12:41:25.39 |
-34:19:52.1 |
HIP 62037 |
19.13 |
| 2026-05-23 00:00 |
12:41:20.92 |
-34:18:57.6 |
HIP 61785 |
19.05 |
| 2026-05-23 12:00 |
12:41:16.50 |
-34:18:03.2 |
HIP 61785 |
18.35 |
| 2026-05-24 00:00 |
12:41:12.12 |
-34:17:08.7 |
HIP 61785 |
17.73 |
| 2026-05-24 12:00 |
12:41:07.79 |
-34:16:14.2 |
HIP 61785 |
17.19 |
| 2026-05-25 00:00 |
12:41:03.50 |
-34:15:19.8 |
HIP 61785 |
16.74 |
| 2026-05-25 12:00 |
12:40:59.26 |
-34:14:25.3 |
HIP 61785 |
16.38 |
| 2026-05-26 00:00 |
12:40:55.07 |
-34:13:30.9 |
HIP 61785 |
16.12 |
| 2026-05-26 12:00 |
12:40:50.92 |
-34:12:36.4 |
HIP 61785 |
15.96 |
| 2026-05-27 00:00 |
12:40:46.83 |
-34:11:42.0 |
HIP 61785 |
15.90 |
| 2026-05-27 12:00 |
12:40:42.77 |
-34:10:47.6 |
HIP 61785 |
15.95 |
| 2026-05-28 00:00 |
12:40:38.77 |
-34:09:53.2 |
HIP 61785 |
16.10 |
| 2026-05-28 12:00 |
12:40:34.81 |
-34:08:58.9 |
HIP 61785 |
16.34 |
| 2026-05-29 00:00 |
12:40:30.91 |
-34:08:04.6 |
HIP 61785 |
16.68 |
| 2026-05-29 12:00 |
12:40:27.05 |
-34:07:10.3 |
HIP 61785 |
17.10 |
| 2026-05-30 00:00 |
12:40:23.23 |
-34:06:16.1 |
HIP 61785 |
17.59 |
| 2026-05-30 12:00 |
12:40:19.47 |
-34:05:21.9 |
HIP 61785 |
18.15 |
| 2026-05-31 00:00 |
12:40:15.75 |
-34:04:27.8 |
HIP 61757 |
18.76 |
| 2026-05-31 12:00 |
12:40:12.09 |
-34:03:33.7 |
HIP 61757 |
17.59 |
| 2026-06-01 00:00 |
12:40:08.47 |
-34:02:39.7 |
HIP 61757 |
16.43 |
| 2026-06-01 12:00 |
12:40:04.90 |
-34:01:45.8 |
HIP 61757 |
15.27 |
| 2026-06-02 00:00 |
12:40:01.38 |
-34:00:51.9 |
HIP 61757 |
14.12 |