C/2013 D1 (Holvorcem)
| Parameter |
Value |
| Designation |
C/2013 D1 (Holvorcem) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-04-13T17:17:27.458880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:30Z |
| Obs used |
118 |
| NEO |
- |
| M1 |
13.500 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-03-26.0000000 |
| e |
0.78087861 |
| q (au) |
2.460129 |
| a (au) |
11.227243 |
| i (deg) |
10.093564 |
| Ω (om, deg) |
294.974884 |
| ω (w, deg) |
252.631501 |
| M (ma, deg) |
359.509532 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.750 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.750 |
| n |
6.000 |
| gf |
0.967 |
| gb |
-0.790 |
| k |
0.800 |
| δ90 |
5.235 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
23:22:16.19 |
+05:07:17.2 |
HIP 115364 |
23.31 |
| 2026-02-03 12:00 |
23:22:21.42 |
+05:07:42.5 |
HIP 115364 |
23.11 |
| 2026-02-04 00:00 |
23:22:26.68 |
+05:08:08.1 |
HIP 115364 |
22.99 |
| 2026-02-04 12:00 |
23:22:31.96 |
+05:08:34.0 |
HIP 115364 |
22.95 |
| 2026-02-05 00:00 |
23:22:37.27 |
+05:09:00.2 |
HIP 115364 |
23.00 |
| 2026-02-05 12:00 |
23:22:42.61 |
+05:09:26.6 |
HIP 115364 |
23.12 |
| 2026-02-06 00:00 |
23:22:47.97 |
+05:09:53.3 |
HIP 115364 |
23.33 |
| 2026-02-06 12:00 |
23:22:53.35 |
+05:10:20.2 |
HIP 115524 |
22.84 |
| 2026-02-07 00:00 |
23:22:58.75 |
+05:10:47.4 |
HIP 115524 |
22.12 |
| 2026-02-07 12:00 |
23:23:04.18 |
+05:11:14.8 |
HIP 115524 |
21.46 |
| 2026-02-08 00:00 |
23:23:09.64 |
+05:11:42.5 |
HIP 115524 |
20.89 |
| 2026-02-08 12:00 |
23:23:15.11 |
+05:12:10.5 |
HIP 115524 |
20.39 |
| 2026-02-09 00:00 |
23:23:20.61 |
+05:12:38.7 |
HIP 115524 |
19.99 |
| 2026-02-09 12:00 |
23:23:26.13 |
+05:13:07.1 |
HIP 115524 |
19.69 |
| 2026-02-10 00:00 |
23:23:31.68 |
+05:13:35.8 |
HIP 115524 |
19.50 |
| 2026-02-10 12:00 |
23:23:37.24 |
+05:14:04.8 |
HIP 115524 |
19.41 |
| 2026-02-11 00:00 |
23:23:42.82 |
+05:14:34.0 |
HIP 115524 |
19.44 |
| 2026-02-11 12:00 |
23:23:48.43 |
+05:15:03.4 |
HIP 115524 |
19.58 |
| 2026-02-12 00:00 |
23:23:54.06 |
+05:15:33.1 |
HIP 115524 |
19.83 |
| 2026-02-12 12:00 |
23:23:59.70 |
+05:16:03.0 |
HIP 115524 |
20.20 |
| 2026-02-13 00:00 |
23:24:05.37 |
+05:16:33.2 |
HIP 115524 |
20.67 |
| 2026-02-13 12:00 |
23:24:11.05 |
+05:17:03.6 |
HIP 115524 |
21.24 |
| 2026-02-14 00:00 |
23:24:16.76 |
+05:17:34.2 |
HIP 115524 |
21.90 |
| 2026-02-14 12:00 |
23:24:22.48 |
+05:18:05.1 |
HIP 115524 |
22.65 |
| 2026-02-15 00:00 |
23:24:28.22 |
+05:18:36.2 |
HIP 115524 |
23.48 |
| 2026-02-15 12:00 |
23:24:33.98 |
+05:19:07.5 |
HIP 115524 |
24.38 |
| 2026-02-16 00:00 |
23:24:39.76 |
+05:19:39.0 |
HIP 115524 |
25.34 |
| 2026-02-16 12:00 |
23:24:45.55 |
+05:20:10.8 |
HIP 115611 |
25.68 |
| 2026-02-17 00:00 |
23:24:51.37 |
+05:20:42.8 |
HIP 115611 |
25.87 |
| 2026-02-17 12:00 |
23:24:57.19 |
+05:21:15.0 |
HIP 115611 |
26.16 |
| 2026-02-18 00:00 |
23:25:03.04 |
+05:21:47.4 |
HIP 115611 |
26.53 |
| 2026-02-18 12:00 |
23:25:08.90 |
+05:22:20.1 |
HIP 115611 |
27.00 |
| 2026-02-19 00:00 |
23:25:14.77 |
+05:22:52.9 |
HIP 115611 |
27.55 |
| 2026-02-19 12:00 |
23:25:20.66 |
+05:23:26.0 |
HIP 115611 |
28.18 |
| 2026-02-20 00:00 |
23:25:26.56 |
+05:23:59.3 |
HIP 115611 |
28.88 |
| 2026-02-20 12:00 |
23:25:32.48 |
+05:24:32.7 |
HIP 115611 |
29.66 |
| 2026-02-21 00:00 |
23:25:38.41 |
+05:25:06.4 |
HIP 115611 |
30.50 |
| 2026-02-21 12:00 |
23:25:44.36 |
+05:25:40.3 |
HIP 115611 |
31.40 |
| 2026-02-22 00:00 |
23:25:50.32 |
+05:26:14.4 |
HIP 115611 |
32.36 |
| 2026-02-22 12:00 |
23:25:56.29 |
+05:26:48.7 |
HIP 115817 |
32.36 |
| 2026-02-23 00:00 |
23:26:02.27 |
+05:27:23.1 |
HIP 115817 |
30.79 |
| 2026-02-23 12:00 |
23:26:08.27 |
+05:27:57.8 |
HIP 115817 |
29.23 |
| 2026-02-24 00:00 |
23:26:14.27 |
+05:28:32.7 |
HIP 115817 |
27.67 |