| 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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
14:17:58.87 |
-51:04:23.2 |
HIP 69668 |
25.14 |
| 2026-06-03 00:00 |
14:17:53.45 |
-51:03:49.5 |
HIP 69668 |
24.12 |
| 2026-06-03 12:00 |
14:17:48.06 |
-51:03:15.7 |
HIP 69668 |
23.12 |
| 2026-06-04 00:00 |
14:17:42.72 |
-51:02:41.6 |
HIP 69668 |
22.11 |
| 2026-06-04 12:00 |
14:17:37.42 |
-51:02:07.3 |
HIP 69668 |
21.11 |
| 2026-06-05 00:00 |
14:17:32.16 |
-51:01:32.9 |
HIP 69668 |
20.12 |
| 2026-06-05 12:00 |
14:17:26.94 |
-51:00:58.2 |
HIP 69668 |
19.14 |
| 2026-06-06 00:00 |
14:17:21.77 |
-51:00:23.3 |
HIP 69668 |
18.16 |
| 2026-06-06 12:00 |
14:17:16.64 |
-50:59:48.2 |
HIP 69668 |
17.18 |
| 2026-06-07 00:00 |
14:17:11.55 |
-50:59:12.9 |
HIP 69668 |
16.22 |
| 2026-06-07 12:00 |
14:17:06.50 |
-50:58:37.5 |
HIP 69668 |
15.26 |
| 2026-06-08 00:00 |
14:17:01.50 |
-50:58:01.8 |
HIP 69668 |
14.31 |
| 2026-06-08 12:00 |
14:16:56.54 |
-50:57:26.0 |
HIP 69668 |
13.38 |
| 2026-06-09 00:00 |
14:16:51.63 |
-50:56:50.0 |
HIP 69668 |
12.46 |
| 2026-06-09 12:00 |
14:16:46.76 |
-50:56:13.8 |
HIP 69668 |
11.55 |
| 2026-06-10 00:00 |
14:16:41.94 |
-50:55:37.4 |
HIP 69668 |
10.66 |
| 2026-06-10 12:00 |
14:16:37.16 |
-50:55:00.9 |
HIP 69668 |
9.79 |
| 2026-06-11 00:00 |
14:16:32.43 |
-50:54:24.2 |
HIP 69668 |
8.95 |
| 2026-06-11 12:00 |
14:16:27.75 |
-50:53:47.3 |
HIP 69668 |
8.14 |
| 2026-06-12 00:00 |
14:16:23.11 |
-50:53:10.3 |
HIP 69668 |
7.38 |
| 2026-06-12 12:00 |
14:16:18.52 |
-50:52:33.2 |
HIP 69668 |
6.68 |
| 2026-06-13 00:00 |
14:16:13.98 |
-50:51:55.9 |
HIP 69668 |
6.05 |
| 2026-06-13 12:00 |
14:16:09.49 |
-50:51:18.4 |
HIP 69668 |
5.52 |
| 2026-06-14 00:00 |
14:16:05.04 |
-50:50:40.9 |
HIP 69668 |
5.12 |
| 2026-06-14 12:00 |
14:16:00.65 |
-50:50:03.1 |
HIP 69668 |
4.88 |
| 2026-06-15 00:00 |
14:15:56.30 |
-50:49:25.3 |
HIP 69668 |
4.82 |
| 2026-06-15 12:00 |
14:15:52.00 |
-50:48:47.3 |
HIP 69668 |
4.94 |
| 2026-06-16 00:00 |
14:15:47.76 |
-50:48:09.2 |
HIP 69668 |
5.23 |
| 2026-06-16 12:00 |
14:15:43.56 |
-50:47:31.0 |
HIP 69668 |
5.66 |
| 2026-06-17 00:00 |
14:15:39.42 |
-50:46:52.7 |
HIP 69668 |
6.20 |
| 2026-06-17 12:00 |
14:15:35.32 |
-50:46:14.2 |
HIP 69668 |
6.83 |
| 2026-06-18 00:00 |
14:15:31.28 |
-50:45:35.7 |
HIP 69668 |
7.51 |
| 2026-06-18 12:00 |
14:15:27.29 |
-50:44:57.0 |
HIP 69668 |
8.24 |
| 2026-06-19 00:00 |
14:15:23.35 |
-50:44:18.3 |
HIP 69668 |
8.99 |
| 2026-06-19 12:00 |
14:15:19.47 |
-50:43:39.4 |
HIP 69668 |
9.77 |
| 2026-06-20 00:00 |
14:15:15.63 |
-50:43:00.5 |
HIP 69668 |
10.57 |
| 2026-06-20 12:00 |
14:15:11.85 |
-50:42:21.5 |
HIP 69668 |
11.38 |
| 2026-06-21 00:00 |
14:15:08.12 |
-50:41:42.4 |
HIP 69668 |
12.20 |
| 2026-06-21 12:00 |
14:15:04.45 |
-50:41:03.2 |
HIP 69668 |
13.02 |
| 2026-06-22 00:00 |
14:15:00.82 |
-50:40:24.0 |
HIP 69668 |
13.85 |