| 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) |
| 2026-09-20 00:00 |
09:13:11.42 |
+14:07:18.6 |
HIP 45295 |
10.79 |
| 2026-09-20 12:00 |
09:13:14.25 |
+14:07:02.3 |
HIP 45295 |
10.34 |
| 2026-09-21 00:00 |
09:13:17.06 |
+14:06:46.1 |
HIP 45295 |
9.94 |
| 2026-09-21 12:00 |
09:13:19.85 |
+14:06:29.9 |
HIP 45295 |
9.57 |
| 2026-09-22 00:00 |
09:13:22.61 |
+14:06:13.8 |
HIP 45295 |
9.25 |
| 2026-09-22 12:00 |
09:13:25.35 |
+14:05:57.9 |
HIP 45295 |
8.98 |
| 2026-09-23 00:00 |
09:13:28.07 |
+14:05:42.0 |
HIP 45295 |
8.77 |
| 2026-09-23 12:00 |
09:13:30.76 |
+14:05:26.2 |
HIP 45295 |
8.60 |
| 2026-09-24 00:00 |
09:13:33.43 |
+14:05:10.5 |
HIP 45295 |
8.50 |
| 2026-09-24 12:00 |
09:13:36.07 |
+14:04:54.9 |
HIP 45295 |
8.45 |
| 2026-09-25 00:00 |
09:13:38.69 |
+14:04:39.4 |
HIP 45295 |
8.46 |
| 2026-09-25 12:00 |
09:13:41.29 |
+14:04:24.0 |
HIP 45295 |
8.53 |
| 2026-09-26 00:00 |
09:13:43.86 |
+14:04:08.7 |
HIP 45295 |
8.64 |
| 2026-09-26 12:00 |
09:13:46.40 |
+14:03:53.4 |
HIP 45295 |
8.81 |
| 2026-09-27 00:00 |
09:13:48.92 |
+14:03:38.3 |
HIP 45295 |
9.02 |
| 2026-09-27 12:00 |
09:13:51.41 |
+14:03:23.3 |
HIP 45295 |
9.27 |
| 2026-09-28 00:00 |
09:13:53.88 |
+14:03:08.4 |
HIP 45295 |
9.56 |
| 2026-09-28 12:00 |
09:13:56.33 |
+14:02:53.5 |
HIP 45295 |
9.88 |
| 2026-09-29 00:00 |
09:13:58.74 |
+14:02:38.8 |
HIP 45295 |
10.22 |
| 2026-09-29 12:00 |
09:14:01.13 |
+14:02:24.2 |
HIP 45295 |
10.59 |
| 2026-09-30 00:00 |
09:14:03.50 |
+14:02:09.7 |
HIP 45295 |
10.98 |
| 2026-09-30 12:00 |
09:14:05.83 |
+14:01:55.3 |
HIP 45295 |
11.39 |
| 2026-10-01 00:00 |
09:14:08.14 |
+14:01:41.0 |
HIP 45295 |
11.81 |
| 2026-10-01 12:00 |
09:14:10.43 |
+14:01:26.8 |
HIP 45295 |
12.24 |
| 2026-10-02 00:00 |
09:14:12.68 |
+14:01:12.7 |
HIP 45295 |
12.69 |
| 2026-10-02 12:00 |
09:14:14.91 |
+14:00:58.8 |
HIP 45295 |
13.13 |
| 2026-10-03 00:00 |
09:14:17.11 |
+14:00:44.9 |
HIP 45295 |
13.59 |
| 2026-10-03 12:00 |
09:14:19.28 |
+14:00:31.1 |
HIP 45295 |
14.05 |
| 2026-10-04 00:00 |
09:14:21.43 |
+14:00:17.5 |
HIP 45295 |
14.51 |
| 2026-10-04 12:00 |
09:14:23.55 |
+14:00:04.0 |
HIP 45295 |
14.98 |
| 2026-10-05 00:00 |
09:14:25.63 |
+13:59:50.6 |
HIP 45295 |
15.44 |
| 2026-10-05 12:00 |
09:14:27.69 |
+13:59:37.3 |
HIP 45295 |
15.91 |
| 2026-10-06 00:00 |
09:14:29.72 |
+13:59:24.1 |
HIP 45295 |
16.37 |
| 2026-10-06 12:00 |
09:14:31.72 |
+13:59:11.1 |
HIP 45295 |
16.83 |
| 2026-10-07 00:00 |
09:14:33.69 |
+13:58:58.2 |
HIP 45295 |
17.29 |
| 2026-10-07 12:00 |
09:14:35.64 |
+13:58:45.3 |
HIP 45295 |
17.75 |
| 2026-10-08 00:00 |
09:14:37.55 |
+13:58:32.7 |
HIP 45295 |
18.21 |
| 2026-10-08 12:00 |
09:14:39.43 |
+13:58:20.1 |
HIP 45295 |
18.66 |
| 2026-10-09 00:00 |
09:14:41.28 |
+13:58:07.7 |
HIP 45295 |
19.11 |
| 2026-10-09 12:00 |
09:14:43.10 |
+13:57:55.4 |
HIP 45295 |
19.55 |
| 2026-10-10 00:00 |
09:14:44.89 |
+13:57:43.2 |
HIP 45295 |
19.99 |
| 2026-10-10 12:00 |
09:14:46.65 |
+13:57:31.1 |
HIP 45295 |
20.43 |
| 2026-10-11 00:00 |
09:14:48.38 |
+13:57:19.2 |
HIP 45295 |
20.86 |