| Parameter |
Value |
| Designation |
C/2013 H1 (La Sagra) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-05-19T16:02:02.639040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:34Z |
| Obs used |
270 |
| NEO |
- |
| M1 |
7.200 |
| K1 |
22.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-05-18.0000000 |
| e |
0.98542562 |
| q (au) |
2.646966 |
| a (au) |
181.617687 |
| i (deg) |
27.089519 |
| Ω (om, deg) |
84.969862 |
| ω (w, deg) |
136.581161 |
| M (ma, deg) |
359.999328 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.300 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.300 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
0.800 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
01:18:47.89 |
-19:37:17.5 |
HIP 6121 |
15.70 |
| 2026-05-12 12:00 |
01:18:51.68 |
-19:37:11.5 |
HIP 6121 |
15.81 |
| 2026-05-13 00:00 |
01:18:55.44 |
-19:37:05.7 |
HIP 6121 |
15.97 |
| 2026-05-13 12:00 |
01:18:59.20 |
-19:37:00.2 |
HIP 6121 |
16.18 |
| 2026-05-14 00:00 |
01:19:02.93 |
-19:36:55.1 |
HIP 6121 |
16.44 |
| 2026-05-14 12:00 |
01:19:06.65 |
-19:36:50.2 |
HIP 6121 |
16.75 |
| 2026-05-15 00:00 |
01:19:10.35 |
-19:36:45.6 |
HIP 6121 |
17.10 |
| 2026-05-15 12:00 |
01:19:14.03 |
-19:36:41.3 |
HIP 6121 |
17.48 |
| 2026-05-16 00:00 |
01:19:17.70 |
-19:36:37.3 |
HIP 6121 |
17.90 |
| 2026-05-16 12:00 |
01:19:21.35 |
-19:36:33.6 |
HIP 6121 |
18.36 |
| 2026-05-17 00:00 |
01:19:24.98 |
-19:36:30.2 |
HIP 6121 |
18.84 |
| 2026-05-17 12:00 |
01:19:28.59 |
-19:36:27.0 |
HIP 6121 |
19.35 |
| 2026-05-18 00:00 |
01:19:32.18 |
-19:36:24.2 |
HIP 6121 |
19.89 |
| 2026-05-18 12:00 |
01:19:35.75 |
-19:36:21.7 |
HIP 6121 |
20.44 |
| 2026-05-19 00:00 |
01:19:39.30 |
-19:36:19.5 |
HIP 6121 |
21.02 |
| 2026-05-19 12:00 |
01:19:42.84 |
-19:36:17.5 |
HIP 6121 |
21.61 |
| 2026-05-20 00:00 |
01:19:46.35 |
-19:36:15.9 |
HIP 6121 |
22.22 |
| 2026-05-20 12:00 |
01:19:49.85 |
-19:36:14.5 |
HIP 6273 |
22.72 |
| 2026-05-21 00:00 |
01:19:53.32 |
-19:36:13.5 |
HIP 6273 |
22.41 |
| 2026-05-21 12:00 |
01:19:56.78 |
-19:36:12.7 |
HIP 6273 |
22.12 |
| 2026-05-22 00:00 |
01:20:00.21 |
-19:36:12.2 |
HIP 6273 |
21.85 |
| 2026-05-22 12:00 |
01:20:03.62 |
-19:36:12.0 |
HIP 6273 |
21.61 |
| 2026-05-23 00:00 |
01:20:07.02 |
-19:36:12.2 |
HIP 6273 |
21.40 |
| 2026-05-23 12:00 |
01:20:10.39 |
-19:36:12.6 |
HIP 6273 |
21.20 |
| 2026-05-24 00:00 |
01:20:13.74 |
-19:36:13.3 |
HIP 6273 |
21.04 |
| 2026-05-24 12:00 |
01:20:17.07 |
-19:36:14.3 |
HIP 6273 |
20.89 |
| 2026-05-25 00:00 |
01:20:20.37 |
-19:36:15.5 |
HIP 6273 |
20.77 |
| 2026-05-25 12:00 |
01:20:23.66 |
-19:36:17.1 |
HIP 6273 |
20.68 |
| 2026-05-26 00:00 |
01:20:26.92 |
-19:36:19.0 |
HIP 6273 |
20.60 |
| 2026-05-26 12:00 |
01:20:30.16 |
-19:36:21.2 |
HIP 6273 |
20.56 |
| 2026-05-27 00:00 |
01:20:33.38 |
-19:36:23.6 |
HIP 6273 |
20.53 |
| 2026-05-27 12:00 |
01:20:36.58 |
-19:36:26.3 |
HIP 6273 |
20.53 |
| 2026-05-28 00:00 |
01:20:39.75 |
-19:36:29.4 |
HIP 6273 |
20.55 |
| 2026-05-28 12:00 |
01:20:42.90 |
-19:36:32.7 |
HIP 6273 |
20.59 |
| 2026-05-29 00:00 |
01:20:46.03 |
-19:36:36.3 |
HIP 6273 |
20.65 |
| 2026-05-29 12:00 |
01:20:49.13 |
-19:36:40.2 |
HIP 6273 |
20.73 |
| 2026-05-30 00:00 |
01:20:52.21 |
-19:36:44.4 |
HIP 6409 |
20.61 |
| 2026-05-30 12:00 |
01:20:55.27 |
-19:36:48.9 |
HIP 6409 |
19.90 |
| 2026-05-31 00:00 |
01:20:58.30 |
-19:36:53.6 |
HIP 6409 |
19.20 |
| 2026-05-31 12:00 |
01:21:01.31 |
-19:36:58.7 |
HIP 6409 |
18.50 |
| 2026-06-01 00:00 |
01:21:04.30 |
-19:37:04.0 |
HIP 6409 |
17.82 |
| 2026-06-01 12:00 |
01:21:07.26 |
-19:37:09.6 |
HIP 6409 |
17.14 |
| 2026-06-02 00:00 |
01:21:10.20 |
-19:37:15.5 |
HIP 6409 |
16.47 |