| 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 |
2014-08-12 |
+15.6290 |
-0.425 |
| 2014-08-12 |
2015-02-26 |
-4.0603 |
+1.408 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
09:02:24.28 |
+15:01:47.2 |
HIP 44313 |
16.38 |
| 2026-03-26 12:00 |
09:02:21.21 |
+15:01:59.9 |
HIP 44313 |
15.66 |
| 2026-03-27 00:00 |
09:02:18.18 |
+15:02:12.4 |
HIP 44313 |
14.96 |
| 2026-03-27 12:00 |
09:02:15.17 |
+15:02:24.7 |
HIP 44313 |
14.27 |
| 2026-03-28 00:00 |
09:02:12.20 |
+15:02:37.0 |
HIP 44313 |
13.59 |
| 2026-03-28 12:00 |
09:02:09.27 |
+15:02:49.1 |
HIP 44313 |
12.93 |
| 2026-03-29 00:00 |
09:02:06.37 |
+15:03:01.0 |
HIP 44313 |
12.28 |
| 2026-03-29 12:00 |
09:02:03.50 |
+15:03:12.8 |
HIP 44313 |
11.65 |
| 2026-03-30 00:00 |
09:02:00.67 |
+15:03:24.5 |
HIP 44313 |
11.04 |
| 2026-03-30 12:00 |
09:01:57.87 |
+15:03:36.1 |
HIP 44313 |
10.45 |
| 2026-03-31 00:00 |
09:01:55.10 |
+15:03:47.5 |
HIP 44313 |
9.88 |
| 2026-03-31 12:00 |
09:01:52.37 |
+15:03:58.7 |
HIP 44313 |
9.33 |
| 2026-04-01 00:00 |
09:01:49.68 |
+15:04:09.9 |
HIP 44313 |
8.81 |
| 2026-04-01 12:00 |
09:01:47.02 |
+15:04:20.9 |
HIP 44313 |
8.32 |
| 2026-04-02 00:00 |
09:01:44.39 |
+15:04:31.7 |
HIP 44313 |
7.86 |
| 2026-04-02 12:00 |
09:01:41.80 |
+15:04:42.4 |
HIP 44313 |
7.44 |
| 2026-04-03 00:00 |
09:01:39.24 |
+15:04:53.0 |
HIP 44313 |
7.06 |
| 2026-04-03 12:00 |
09:01:36.72 |
+15:05:03.4 |
HIP 44313 |
6.72 |
| 2026-04-04 00:00 |
09:01:34.24 |
+15:05:13.7 |
HIP 44313 |
6.42 |
| 2026-04-04 12:00 |
09:01:31.79 |
+15:05:23.8 |
HIP 44313 |
6.18 |
| 2026-04-05 00:00 |
09:01:29.37 |
+15:05:33.8 |
HIP 44313 |
6.00 |
| 2026-04-05 12:00 |
09:01:26.99 |
+15:05:43.6 |
HIP 44313 |
5.87 |
| 2026-04-06 00:00 |
09:01:24.65 |
+15:05:53.3 |
HIP 44313 |
5.81 |
| 2026-04-06 12:00 |
09:01:22.34 |
+15:06:02.9 |
HIP 44313 |
5.80 |
| 2026-04-07 00:00 |
09:01:20.07 |
+15:06:12.3 |
HIP 44313 |
5.85 |
| 2026-04-07 12:00 |
09:01:17.84 |
+15:06:21.6 |
HIP 44313 |
5.95 |
| 2026-04-08 00:00 |
09:01:15.64 |
+15:06:30.7 |
HIP 44313 |
6.10 |
| 2026-04-08 12:00 |
09:01:13.48 |
+15:06:39.6 |
HIP 44313 |
6.29 |
| 2026-04-09 00:00 |
09:01:11.35 |
+15:06:48.4 |
HIP 44313 |
6.52 |
| 2026-04-09 12:00 |
09:01:09.26 |
+15:06:57.1 |
HIP 44313 |
6.77 |
| 2026-04-10 00:00 |
09:01:07.21 |
+15:07:05.6 |
HIP 44313 |
7.05 |
| 2026-04-10 12:00 |
09:01:05.19 |
+15:07:14.0 |
HIP 44313 |
7.35 |
| 2026-04-11 00:00 |
09:01:03.22 |
+15:07:22.2 |
HIP 44313 |
7.67 |
| 2026-04-11 12:00 |
09:01:01.28 |
+15:07:30.2 |
HIP 44313 |
7.99 |
| 2026-04-12 00:00 |
09:00:59.37 |
+15:07:38.2 |
HIP 44313 |
8.33 |
| 2026-04-12 12:00 |
09:00:57.50 |
+15:07:45.9 |
HIP 44313 |
8.67 |
| 2026-04-13 00:00 |
09:00:55.68 |
+15:07:53.5 |
HIP 44313 |
9.02 |
| 2026-04-13 12:00 |
09:00:53.88 |
+15:08:01.0 |
HIP 44313 |
9.37 |
| 2026-04-14 00:00 |
09:00:52.13 |
+15:08:08.2 |
HIP 44313 |
9.72 |
| 2026-04-14 12:00 |
09:00:50.41 |
+15:08:15.4 |
HIP 44313 |
10.07 |
| 2026-04-15 00:00 |
09:00:48.73 |
+15:08:22.4 |
HIP 44295 |
10.31 |
| 2026-04-15 12:00 |
09:00:47.09 |
+15:08:29.2 |
HIP 44295 |
10.50 |
| 2026-04-16 00:00 |
09:00:45.49 |
+15:08:35.9 |
HIP 44295 |
10.70 |