C/2013 UQ4 (Catalina)
| Parameter |
Value |
| Designation |
C/2013 UQ4 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2014-07-05T23:01:47.953920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:42Z |
| Obs used |
1853 |
| NEO |
- |
| M1 |
13.800 |
| K1 |
6.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-07-12.0000000 |
| e |
0.98215354 |
| q (au) |
1.080975 |
| a (au) |
60.570843 |
| i (deg) |
145.258572 |
| Ω (om, deg) |
317.662397 |
| ω (w, deg) |
23.312164 |
| M (ma, deg) |
0.012629 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.588 + 5.145\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.588 |
| n |
5.145 |
| gf |
0.800 |
| gb |
-0.748 |
| k |
0.800 |
| δ90 |
3.096 |
| 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 |
| 2014-05-07 |
2014-07-05 |
-2.4544 |
-0.050 |
| 2014-07-05 |
2014-11-07 |
+3.0088 |
+0.332 |
| 2014-11-07 |
2015-02-26 |
-8.0631 |
+3.467 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
09:09:42.85 |
+14:32:13.0 |
HIP 44997 |
5.52 |
| 2026-02-03 12:00 |
09:09:37.91 |
+14:32:32.6 |
HIP 44997 |
6.44 |
| 2026-02-04 00:00 |
09:09:32.98 |
+14:32:52.2 |
HIP 44997 |
7.46 |
| 2026-02-04 12:00 |
09:09:28.04 |
+14:33:11.7 |
HIP 44997 |
8.54 |
| 2026-02-05 00:00 |
09:09:23.11 |
+14:33:31.3 |
HIP 44997 |
9.66 |
| 2026-02-05 12:00 |
09:09:18.17 |
+14:33:50.9 |
HIP 44997 |
10.80 |
| 2026-02-06 00:00 |
09:09:13.24 |
+14:34:10.5 |
HIP 44997 |
11.96 |
| 2026-02-06 12:00 |
09:09:08.31 |
+14:34:30.1 |
HIP 44997 |
13.13 |
| 2026-02-07 00:00 |
09:09:03.38 |
+14:34:49.7 |
HIP 44997 |
14.32 |
| 2026-02-07 12:00 |
09:08:58.46 |
+14:35:09.4 |
HIP 44838 |
14.26 |
| 2026-02-08 00:00 |
09:08:53.53 |
+14:35:29.0 |
HIP 44838 |
13.08 |
| 2026-02-08 12:00 |
09:08:48.61 |
+14:35:48.6 |
HIP 44838 |
11.91 |
| 2026-02-09 00:00 |
09:08:43.70 |
+14:36:08.2 |
HIP 44838 |
10.76 |
| 2026-02-09 12:00 |
09:08:38.79 |
+14:36:27.8 |
HIP 44838 |
9.63 |
| 2026-02-10 00:00 |
09:08:33.88 |
+14:36:47.4 |
HIP 44838 |
8.53 |
| 2026-02-10 12:00 |
09:08:28.98 |
+14:37:06.9 |
HIP 44838 |
7.47 |
| 2026-02-11 00:00 |
09:08:24.08 |
+14:37:26.5 |
HIP 44838 |
6.47 |
| 2026-02-11 12:00 |
09:08:19.19 |
+14:37:46.1 |
HIP 44838 |
5.57 |
| 2026-02-12 00:00 |
09:08:14.31 |
+14:38:05.6 |
HIP 44838 |
4.81 |
| 2026-02-12 12:00 |
09:08:09.43 |
+14:38:25.1 |
HIP 44838 |
4.27 |
| 2026-02-13 00:00 |
09:08:04.56 |
+14:38:44.6 |
HIP 44838 |
4.05 |
| 2026-02-13 12:00 |
09:07:59.70 |
+14:39:04.1 |
HIP 44838 |
4.18 |
| 2026-02-14 00:00 |
09:07:54.85 |
+14:39:23.6 |
HIP 44838 |
4.65 |
| 2026-02-14 12:00 |
09:07:50.00 |
+14:39:43.0 |
HIP 44838 |
5.35 |
| 2026-02-15 00:00 |
09:07:45.16 |
+14:40:02.4 |
HIP 44838 |
6.21 |
| 2026-02-15 12:00 |
09:07:40.33 |
+14:40:21.8 |
HIP 44838 |
7.17 |
| 2026-02-16 00:00 |
09:07:35.51 |
+14:40:41.2 |
HIP 44838 |
8.20 |
| 2026-02-16 12:00 |
09:07:30.71 |
+14:41:00.5 |
HIP 44838 |
9.27 |
| 2026-02-17 00:00 |
09:07:25.91 |
+14:41:19.8 |
HIP 44838 |
10.37 |
| 2026-02-17 12:00 |
09:07:21.12 |
+14:41:39.1 |
HIP 44838 |
11.48 |
| 2026-02-18 00:00 |
09:07:16.34 |
+14:41:58.3 |
HIP 44838 |
12.61 |
| 2026-02-18 12:00 |
09:07:11.58 |
+14:42:17.5 |
HIP 44838 |
13.75 |
| 2026-02-19 00:00 |
09:07:06.83 |
+14:42:36.6 |
HIP 44838 |
14.89 |
| 2026-02-19 12:00 |
09:07:02.09 |
+14:42:55.7 |
HIP 44838 |
16.04 |
| 2026-02-20 00:00 |
09:06:57.36 |
+14:43:14.8 |
HIP 44838 |
17.19 |
| 2026-02-20 12:00 |
09:06:52.64 |
+14:43:33.8 |
HIP 44838 |
18.34 |
| 2026-02-21 00:00 |
09:06:47.94 |
+14:43:52.7 |
HIP 44838 |
19.49 |
| 2026-02-21 12:00 |
09:06:43.26 |
+14:44:11.6 |
HIP 44838 |
20.64 |
| 2026-02-22 00:00 |
09:06:38.58 |
+14:44:30.5 |
HIP 44838 |
21.79 |
| 2026-02-22 12:00 |
09:06:33.93 |
+14:44:49.3 |
HIP 44838 |
22.94 |
| 2026-02-23 00:00 |
09:06:29.28 |
+14:45:08.1 |
HIP 44838 |
24.09 |
| 2026-02-23 12:00 |
09:06:24.66 |
+14:45:26.8 |
HIP 44838 |
25.24 |
| 2026-02-24 00:00 |
09:06:20.05 |
+14:45:45.4 |
HIP 44838 |
26.38 |