| 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 |
1.000 |
| gb |
-0.790 |
| k |
0.800 |
| δ90 |
5.227 |
| 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) |
| 2026-09-20 00:00 |
23:32:47.95 |
+07:17:37.9 |
HIP 116164 |
15.28 |
| 2026-09-20 12:00 |
23:32:42.54 |
+07:17:03.3 |
HIP 116164 |
14.06 |
| 2026-09-21 00:00 |
23:32:37.14 |
+07:16:28.6 |
HIP 116164 |
12.89 |
| 2026-09-21 12:00 |
23:32:31.74 |
+07:15:53.8 |
HIP 116164 |
11.78 |
| 2026-09-22 00:00 |
23:32:26.34 |
+07:15:18.8 |
HIP 116164 |
10.76 |
| 2026-09-22 12:00 |
23:32:20.96 |
+07:14:43.7 |
HIP 116164 |
9.84 |
| 2026-09-23 00:00 |
23:32:15.58 |
+07:14:08.6 |
HIP 116164 |
9.07 |
| 2026-09-23 12:00 |
23:32:10.20 |
+07:13:33.3 |
HIP 116164 |
8.48 |
| 2026-09-24 00:00 |
23:32:04.84 |
+07:12:57.9 |
HIP 116164 |
8.10 |
| 2026-09-24 12:00 |
23:31:59.48 |
+07:12:22.4 |
HIP 116164 |
7.98 |
| 2026-09-25 00:00 |
23:31:54.14 |
+07:11:46.8 |
HIP 116164 |
8.11 |
| 2026-09-25 12:00 |
23:31:48.80 |
+07:11:11.2 |
HIP 116164 |
8.50 |
| 2026-09-26 00:00 |
23:31:43.47 |
+07:10:35.4 |
HIP 116164 |
9.10 |
| 2026-09-26 12:00 |
23:31:38.16 |
+07:09:59.6 |
HIP 116164 |
9.87 |
| 2026-09-27 00:00 |
23:31:32.85 |
+07:09:23.6 |
HIP 116164 |
10.78 |
| 2026-09-27 12:00 |
23:31:27.56 |
+07:08:47.6 |
HIP 116164 |
11.79 |
| 2026-09-28 00:00 |
23:31:22.27 |
+07:08:11.5 |
HIP 116164 |
12.89 |
| 2026-09-28 12:00 |
23:31:17.00 |
+07:07:35.4 |
HIP 116164 |
14.04 |
| 2026-09-29 00:00 |
23:31:11.75 |
+07:06:59.1 |
HIP 116164 |
15.24 |
| 2026-09-29 12:00 |
23:31:06.50 |
+07:06:22.8 |
HIP 116164 |
16.48 |
| 2026-09-30 00:00 |
23:31:01.27 |
+07:05:46.5 |
HIP 116164 |
17.74 |
| 2026-09-30 12:00 |
23:30:56.06 |
+07:05:10.1 |
HIP 116164 |
19.02 |
| 2026-10-01 00:00 |
23:30:50.86 |
+07:04:33.6 |
HIP 116164 |
20.31 |
| 2026-10-01 12:00 |
23:30:45.67 |
+07:03:57.1 |
HIP 116164 |
21.63 |
| 2026-10-02 00:00 |
23:30:40.50 |
+07:03:20.5 |
HIP 116164 |
22.94 |
| 2026-10-02 12:00 |
23:30:35.35 |
+07:02:43.9 |
HIP 116164 |
24.27 |
| 2026-10-03 00:00 |
23:30:30.21 |
+07:02:07.2 |
HIP 116164 |
25.61 |
| 2026-10-03 12:00 |
23:30:25.09 |
+07:01:30.5 |
HIP 116164 |
26.94 |
| 2026-10-04 00:00 |
23:30:19.99 |
+07:00:53.7 |
HIP 116164 |
28.28 |
| 2026-10-04 12:00 |
23:30:14.90 |
+07:00:17.0 |
HIP 116164 |
29.62 |
| 2026-10-05 00:00 |
23:30:09.84 |
+06:59:40.1 |
HIP 116164 |
30.97 |
| 2026-10-05 12:00 |
23:30:04.79 |
+06:59:03.3 |
HIP 115883 |
30.75 |
| 2026-10-06 00:00 |
23:29:59.76 |
+06:58:26.5 |
HIP 115883 |
30.41 |
| 2026-10-06 12:00 |
23:29:54.76 |
+06:57:49.6 |
HIP 115883 |
30.14 |
| 2026-10-07 00:00 |
23:29:49.77 |
+06:57:12.7 |
HIP 115883 |
29.93 |
| 2026-10-07 12:00 |
23:29:44.81 |
+06:56:35.8 |
HIP 115883 |
29.78 |
| 2026-10-08 00:00 |
23:29:39.86 |
+06:55:58.9 |
HIP 115883 |
29.70 |
| 2026-10-08 12:00 |
23:29:34.94 |
+06:55:22.0 |
HIP 115883 |
29.69 |
| 2026-10-09 00:00 |
23:29:30.05 |
+06:54:45.1 |
HIP 115883 |
29.74 |
| 2026-10-09 12:00 |
23:29:25.17 |
+06:54:08.2 |
HIP 115883 |
29.86 |
| 2026-10-10 00:00 |
23:29:20.32 |
+06:53:31.3 |
HIP 115883 |
30.04 |
| 2026-10-10 12:00 |
23:29:15.49 |
+06:52:54.4 |
HIP 115883 |
30.28 |
| 2026-10-11 00:00 |
23:29:10.69 |
+06:52:17.6 |
HIP 115883 |
30.58 |