| 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) |
| 2026-03-26 00:00 |
23:32:22.46 |
+06:07:49.3 |
HIP 116015 |
34.82 |
| 2026-03-26 12:00 |
23:32:28.51 |
+06:08:31.6 |
HIP 116015 |
35.78 |
| 2026-03-27 00:00 |
23:32:34.54 |
+06:09:13.9 |
HIP 116015 |
36.79 |
| 2026-03-27 12:00 |
23:32:40.56 |
+06:09:56.3 |
HIP 116015 |
37.84 |
| 2026-03-28 00:00 |
23:32:46.58 |
+06:10:38.7 |
HIP 116015 |
38.93 |
| 2026-03-28 12:00 |
23:32:52.58 |
+06:11:21.1 |
HIP 116015 |
40.05 |
| 2026-03-29 00:00 |
23:32:58.57 |
+06:12:03.6 |
HIP 116239 |
39.33 |
| 2026-03-29 12:00 |
23:33:04.54 |
+06:12:46.2 |
HIP 116239 |
38.54 |
| 2026-03-30 00:00 |
23:33:10.51 |
+06:13:28.7 |
HIP 116239 |
37.80 |
| 2026-03-30 12:00 |
23:33:16.46 |
+06:14:11.3 |
HIP 116239 |
37.12 |
| 2026-03-31 00:00 |
23:33:22.40 |
+06:14:54.0 |
HIP 116239 |
36.51 |
| 2026-03-31 12:00 |
23:33:28.33 |
+06:15:36.6 |
HIP 116239 |
35.95 |
| 2026-04-01 00:00 |
23:33:34.24 |
+06:16:19.3 |
HIP 116239 |
35.46 |
| 2026-04-01 12:00 |
23:33:40.14 |
+06:17:02.0 |
HIP 116239 |
35.04 |
| 2026-04-02 00:00 |
23:33:46.02 |
+06:17:44.8 |
HIP 116239 |
34.69 |
| 2026-04-02 12:00 |
23:33:51.90 |
+06:18:27.5 |
HIP 116239 |
34.41 |
| 2026-04-03 00:00 |
23:33:57.75 |
+06:19:10.3 |
HIP 116239 |
34.21 |
| 2026-04-03 12:00 |
23:34:03.59 |
+06:19:53.1 |
HIP 116239 |
34.08 |
| 2026-04-04 00:00 |
23:34:09.42 |
+06:20:35.9 |
HIP 116239 |
34.02 |
| 2026-04-04 12:00 |
23:34:15.23 |
+06:21:18.7 |
HIP 116239 |
34.04 |
| 2026-04-05 00:00 |
23:34:21.02 |
+06:22:01.5 |
HIP 116239 |
34.13 |
| 2026-04-05 12:00 |
23:34:26.80 |
+06:22:44.3 |
HIP 116239 |
34.29 |
| 2026-04-06 00:00 |
23:34:32.56 |
+06:23:27.2 |
HIP 116511 |
32.92 |
| 2026-04-06 12:00 |
23:34:38.30 |
+06:24:10.0 |
HIP 116511 |
31.33 |
| 2026-04-07 00:00 |
23:34:44.03 |
+06:24:52.8 |
HIP 116511 |
29.74 |
| 2026-04-07 12:00 |
23:34:49.74 |
+06:25:35.7 |
HIP 116511 |
28.16 |
| 2026-04-08 00:00 |
23:34:55.43 |
+06:26:18.5 |
HIP 116511 |
26.59 |
| 2026-04-08 12:00 |
23:35:01.11 |
+06:27:01.3 |
HIP 116511 |
25.02 |
| 2026-04-09 00:00 |
23:35:06.76 |
+06:27:44.1 |
HIP 116511 |
23.46 |
| 2026-04-09 12:00 |
23:35:12.40 |
+06:28:26.9 |
HIP 116511 |
21.90 |
| 2026-04-10 00:00 |
23:35:18.02 |
+06:29:09.7 |
HIP 116511 |
20.35 |
| 2026-04-10 12:00 |
23:35:23.61 |
+06:29:52.5 |
HIP 116511 |
18.81 |
| 2026-04-11 00:00 |
23:35:29.19 |
+06:30:35.3 |
HIP 116511 |
17.28 |
| 2026-04-11 12:00 |
23:35:34.75 |
+06:31:18.0 |
HIP 116511 |
15.75 |
| 2026-04-12 00:00 |
23:35:40.29 |
+06:32:00.7 |
HIP 116511 |
14.24 |
| 2026-04-12 12:00 |
23:35:45.81 |
+06:32:43.4 |
HIP 116511 |
12.74 |
| 2026-04-13 00:00 |
23:35:51.30 |
+06:33:26.1 |
HIP 116511 |
11.26 |
| 2026-04-13 12:00 |
23:35:56.78 |
+06:34:08.7 |
HIP 116511 |
9.81 |
| 2026-04-14 00:00 |
23:36:02.23 |
+06:34:51.3 |
HIP 116511 |
8.38 |
| 2026-04-14 12:00 |
23:36:07.66 |
+06:35:33.8 |
HIP 116511 |
7.01 |
| 2026-04-15 00:00 |
23:36:13.07 |
+06:36:16.4 |
HIP 116511 |
5.72 |
| 2026-04-15 12:00 |
23:36:18.46 |
+06:36:58.9 |
HIP 116511 |
4.58 |
| 2026-04-16 00:00 |
23:36:23.82 |
+06:37:41.3 |
HIP 116511 |
3.71 |