| Parameter |
Value |
| Designation |
C/2013 U2 (Holvorcem) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2014-10-25T20:53:27.847680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:42Z |
| Obs used |
471 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
11.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-11-05.0000000 |
| e |
0.99429888 |
| q (au) |
5.116737 |
| a (au) |
897.497310 |
| i (deg) |
43.094095 |
| Ω (om, deg) |
7.001119 |
| ω (w, deg) |
107.375509 |
| M (ma, deg) |
0.000371 |
Magnitude
Scatter + Global Linear
$$
M_a = (2.650 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
2.650 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.503 |
| k |
1.000 |
| 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 |
| 2013-10-23 |
2014-10-24 |
+10.6160 |
-7.950 |
| 2014-11-29 |
2016-03-11 |
+5.6262 |
-4.008 |
| 2016-03-11 |
2017-03-27 |
+0.3891 |
-0.346 |
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 |
14:22:23.54 |
-51:24:15.7 |
HIP 70157 |
10.63 |
| 2026-05-12 12:00 |
14:22:16.85 |
-51:23:54.6 |
HIP 70157 |
9.53 |
| 2026-05-13 00:00 |
14:22:10.17 |
-51:23:33.1 |
HIP 70157 |
8.44 |
| 2026-05-13 12:00 |
14:22:03.51 |
-51:23:11.3 |
HIP 70157 |
7.34 |
| 2026-05-14 00:00 |
14:21:56.87 |
-51:22:49.2 |
HIP 70157 |
6.26 |
| 2026-05-14 12:00 |
14:21:50.25 |
-51:22:26.6 |
HIP 70157 |
5.18 |
| 2026-05-15 00:00 |
14:21:43.65 |
-51:22:03.8 |
HIP 70157 |
4.11 |
| 2026-05-15 12:00 |
14:21:37.07 |
-51:21:40.6 |
HIP 70157 |
3.07 |
| 2026-05-16 00:00 |
14:21:30.51 |
-51:21:17.0 |
HIP 70157 |
2.09 |
| 2026-05-16 12:00 |
14:21:23.97 |
-51:20:53.1 |
HIP 70157 |
1.31 |
| 2026-05-17 00:00 |
14:21:17.46 |
-51:20:28.9 |
HIP 70157 |
1.22 |
| 2026-05-17 12:00 |
14:21:10.96 |
-51:20:04.4 |
HIP 70157 |
1.92 |
| 2026-05-18 00:00 |
14:21:04.50 |
-51:19:39.5 |
HIP 70157 |
2.87 |
| 2026-05-18 12:00 |
14:20:58.05 |
-51:19:14.3 |
HIP 70157 |
3.90 |
| 2026-05-19 00:00 |
14:20:51.64 |
-51:18:48.7 |
HIP 70157 |
4.96 |
| 2026-05-19 12:00 |
14:20:45.24 |
-51:18:22.9 |
HIP 70157 |
6.03 |
| 2026-05-20 00:00 |
14:20:38.88 |
-51:17:56.7 |
HIP 70157 |
7.10 |
| 2026-05-20 12:00 |
14:20:32.54 |
-51:17:30.2 |
HIP 70157 |
8.17 |
| 2026-05-21 00:00 |
14:20:26.23 |
-51:17:03.4 |
HIP 70157 |
9.25 |
| 2026-05-21 12:00 |
14:20:19.94 |
-51:16:36.3 |
HIP 70157 |
10.33 |
| 2026-05-22 00:00 |
14:20:13.69 |
-51:16:09.0 |
HIP 70157 |
11.40 |
| 2026-05-22 12:00 |
14:20:07.46 |
-51:15:41.3 |
HIP 70157 |
12.48 |
| 2026-05-23 00:00 |
14:20:01.27 |
-51:15:13.3 |
HIP 70157 |
13.55 |
| 2026-05-23 12:00 |
14:19:55.10 |
-51:14:45.0 |
HIP 70157 |
14.63 |
| 2026-05-24 00:00 |
14:19:48.97 |
-51:14:16.4 |
HIP 70157 |
15.70 |
| 2026-05-24 12:00 |
14:19:42.86 |
-51:13:47.6 |
HIP 70157 |
16.77 |
| 2026-05-25 00:00 |
14:19:36.79 |
-51:13:18.4 |
HIP 70157 |
17.83 |
| 2026-05-25 12:00 |
14:19:30.75 |
-51:12:49.0 |
HIP 70157 |
18.90 |
| 2026-05-26 00:00 |
14:19:24.75 |
-51:12:19.3 |
HIP 70157 |
19.96 |
| 2026-05-26 12:00 |
14:19:18.77 |
-51:11:49.3 |
HIP 70157 |
21.02 |
| 2026-05-27 00:00 |
14:19:12.83 |
-51:11:19.1 |
HIP 69892 |
21.17 |
| 2026-05-27 12:00 |
14:19:06.92 |
-51:10:48.6 |
HIP 69892 |
21.23 |
| 2026-05-28 00:00 |
14:19:01.05 |
-51:10:17.8 |
HIP 69892 |
21.36 |
| 2026-05-28 12:00 |
14:18:55.22 |
-51:09:46.8 |
HIP 69892 |
21.54 |
| 2026-05-29 00:00 |
14:18:49.41 |
-51:09:15.6 |
HIP 69892 |
21.77 |
| 2026-05-29 12:00 |
14:18:43.65 |
-51:08:44.0 |
HIP 69892 |
22.06 |
| 2026-05-30 00:00 |
14:18:37.92 |
-51:08:12.3 |
HIP 69892 |
22.40 |
| 2026-05-30 12:00 |
14:18:32.23 |
-51:07:40.2 |
HIP 69892 |
22.78 |
| 2026-05-31 00:00 |
14:18:26.57 |
-51:07:08.0 |
HIP 69892 |
23.21 |
| 2026-05-31 12:00 |
14:18:20.95 |
-51:06:35.5 |
HIP 69892 |
23.68 |
| 2026-06-01 00:00 |
14:18:15.37 |
-51:06:02.8 |
HIP 69892 |
24.19 |
| 2026-06-01 12:00 |
14:18:09.83 |
-51:05:29.8 |
HIP 69892 |
24.74 |
| 2026-06-02 00:00 |
14:18:04.33 |
-51:04:56.6 |
HIP 69892 |
25.32 |