| 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) |
| 2026-07-29 00:00 |
09:06:51.08 |
+14:40:14.4 |
HIP 44838 |
18.86 |
| 2026-07-29 12:00 |
09:06:54.94 |
+14:39:55.7 |
HIP 44838 |
17.98 |
| 2026-07-30 00:00 |
09:06:58.80 |
+14:39:36.9 |
HIP 44838 |
17.11 |
| 2026-07-30 12:00 |
09:07:02.66 |
+14:39:18.2 |
HIP 44838 |
16.26 |
| 2026-07-31 00:00 |
09:07:06.52 |
+14:38:59.4 |
HIP 44838 |
15.42 |
| 2026-07-31 12:00 |
09:07:10.39 |
+14:38:40.5 |
HIP 44838 |
14.59 |
| 2026-08-01 00:00 |
09:07:14.26 |
+14:38:21.6 |
HIP 44838 |
13.79 |
| 2026-08-01 12:00 |
09:07:18.14 |
+14:38:02.7 |
HIP 44838 |
13.01 |
| 2026-08-02 00:00 |
09:07:22.01 |
+14:37:43.8 |
HIP 44838 |
12.27 |
| 2026-08-02 12:00 |
09:07:25.89 |
+14:37:24.8 |
HIP 44838 |
11.55 |
| 2026-08-03 00:00 |
09:07:29.77 |
+14:37:05.8 |
HIP 44838 |
10.89 |
| 2026-08-03 12:00 |
09:07:33.65 |
+14:36:46.8 |
HIP 44838 |
10.27 |
| 2026-08-04 00:00 |
09:07:37.54 |
+14:36:27.7 |
HIP 44838 |
9.72 |
| 2026-08-04 12:00 |
09:07:41.42 |
+14:36:08.6 |
HIP 44838 |
9.24 |
| 2026-08-05 00:00 |
09:07:45.31 |
+14:35:49.5 |
HIP 44838 |
8.85 |
| 2026-08-05 12:00 |
09:07:49.20 |
+14:35:30.3 |
HIP 44838 |
8.55 |
| 2026-08-06 00:00 |
09:07:53.08 |
+14:35:11.2 |
HIP 44838 |
8.36 |
| 2026-08-06 12:00 |
09:07:56.97 |
+14:34:52.0 |
HIP 44838 |
8.29 |
| 2026-08-07 00:00 |
09:08:00.86 |
+14:34:32.8 |
HIP 44838 |
8.34 |
| 2026-08-07 12:00 |
09:08:04.74 |
+14:34:13.5 |
HIP 44838 |
8.51 |
| 2026-08-08 00:00 |
09:08:08.63 |
+14:33:54.3 |
HIP 44838 |
8.78 |
| 2026-08-08 12:00 |
09:08:12.52 |
+14:33:35.0 |
HIP 44838 |
9.16 |
| 2026-08-09 00:00 |
09:08:16.40 |
+14:33:15.7 |
HIP 44838 |
9.62 |
| 2026-08-09 12:00 |
09:08:20.28 |
+14:32:56.4 |
HIP 44838 |
10.16 |
| 2026-08-10 00:00 |
09:08:24.16 |
+14:32:37.1 |
HIP 44838 |
10.76 |
| 2026-08-10 12:00 |
09:08:28.04 |
+14:32:17.8 |
HIP 44838 |
11.42 |
| 2026-08-11 00:00 |
09:08:31.92 |
+14:31:58.4 |
HIP 44838 |
12.13 |
| 2026-08-11 12:00 |
09:08:35.79 |
+14:31:39.1 |
HIP 44838 |
12.87 |
| 2026-08-12 00:00 |
09:08:39.67 |
+14:31:19.7 |
HIP 44838 |
13.64 |
| 2026-08-12 12:00 |
09:08:43.53 |
+14:31:00.3 |
HIP 44838 |
14.44 |
| 2026-08-13 00:00 |
09:08:47.40 |
+14:30:40.9 |
HIP 44838 |
15.27 |
| 2026-08-13 12:00 |
09:08:51.26 |
+14:30:21.5 |
HIP 44997 |
15.46 |
| 2026-08-14 00:00 |
09:08:55.12 |
+14:30:02.1 |
HIP 44997 |
14.49 |
| 2026-08-14 12:00 |
09:08:58.97 |
+14:29:42.8 |
HIP 44997 |
13.51 |
| 2026-08-15 00:00 |
09:09:02.82 |
+14:29:23.4 |
HIP 44997 |
12.54 |
| 2026-08-15 12:00 |
09:09:06.66 |
+14:29:04.0 |
HIP 44997 |
11.57 |
| 2026-08-16 00:00 |
09:09:10.50 |
+14:28:44.6 |
HIP 44997 |
10.61 |
| 2026-08-16 12:00 |
09:09:14.33 |
+14:28:25.2 |
HIP 44997 |
9.65 |
| 2026-08-17 00:00 |
09:09:18.16 |
+14:28:05.8 |
HIP 44997 |
8.70 |
| 2026-08-17 12:00 |
09:09:21.98 |
+14:27:46.4 |
HIP 44997 |
7.75 |
| 2026-08-18 00:00 |
09:09:25.80 |
+14:27:27.0 |
HIP 44997 |
6.82 |
| 2026-08-18 12:00 |
09:09:29.60 |
+14:27:07.6 |
HIP 44997 |
5.90 |
| 2026-08-19 00:00 |
09:09:33.41 |
+14:26:48.3 |
HIP 44997 |
5.01 |