| Parameter |
Value |
| Designation |
C/2004 C1 (Larsen) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2003-03-19T15:25:34.576320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:36Z |
| Obs used |
94 |
| NEO |
- |
| M1 |
10.000 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2004-02-26.0000000 |
| e |
0.62315774 |
| q (au) |
4.359408 |
| a (au) |
11.568256 |
| i (deg) |
28.916543 |
| Ω (om, deg) |
151.954024 |
| ω (w, deg) |
316.149884 |
| M (ma, deg) |
8.600990 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.482 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.482 |
| n |
6.000 |
| gf |
0.935 |
| gb |
-0.947 |
| k |
1.000 |
| δ90 |
8.473 |
| 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 |
20:06:41.90 |
-03:43:52.4 |
HIP 99024 |
22.09 |
| 2026-05-12 12:00 |
20:06:40.58 |
-03:43:36.8 |
HIP 99024 |
22.23 |
| 2026-05-13 00:00 |
20:06:39.22 |
-03:43:21.4 |
HIP 99024 |
22.37 |
| 2026-05-13 12:00 |
20:06:37.80 |
-03:43:06.2 |
HIP 99024 |
22.51 |
| 2026-05-14 00:00 |
20:06:36.33 |
-03:42:51.2 |
HIP 99024 |
22.65 |
| 2026-05-14 12:00 |
20:06:34.81 |
-03:42:36.5 |
HIP 99024 |
22.79 |
| 2026-05-15 00:00 |
20:06:33.24 |
-03:42:22.0 |
HIP 99024 |
22.93 |
| 2026-05-15 12:00 |
20:06:31.62 |
-03:42:07.8 |
HIP 99024 |
23.07 |
| 2026-05-16 00:00 |
20:06:29.95 |
-03:41:53.8 |
HIP 99024 |
23.22 |
| 2026-05-16 12:00 |
20:06:28.23 |
-03:41:40.0 |
HIP 99024 |
23.37 |
| 2026-05-17 00:00 |
20:06:26.46 |
-03:41:26.4 |
HIP 99024 |
23.52 |
| 2026-05-17 12:00 |
20:06:24.65 |
-03:41:13.1 |
HIP 99024 |
23.67 |
| 2026-05-18 00:00 |
20:06:22.78 |
-03:41:00.0 |
HIP 99024 |
23.83 |
| 2026-05-18 12:00 |
20:06:20.86 |
-03:40:47.2 |
HIP 99024 |
24.00 |
| 2026-05-19 00:00 |
20:06:18.90 |
-03:40:34.6 |
HIP 99024 |
24.17 |
| 2026-05-19 12:00 |
20:06:16.89 |
-03:40:22.3 |
HIP 99024 |
24.34 |
| 2026-05-20 00:00 |
20:06:14.82 |
-03:40:10.2 |
HIP 99024 |
24.53 |
| 2026-05-20 12:00 |
20:06:12.72 |
-03:39:58.3 |
HIP 99024 |
24.72 |
| 2026-05-21 00:00 |
20:06:10.56 |
-03:39:46.7 |
HIP 99024 |
24.91 |
| 2026-05-21 12:00 |
20:06:08.35 |
-03:39:35.4 |
HIP 99024 |
25.12 |
| 2026-05-22 00:00 |
20:06:06.10 |
-03:39:24.3 |
HIP 99024 |
25.33 |
| 2026-05-22 12:00 |
20:06:03.80 |
-03:39:13.4 |
HIP 99024 |
25.55 |
| 2026-05-23 00:00 |
20:06:01.46 |
-03:39:02.8 |
HIP 99024 |
25.78 |
| 2026-05-23 12:00 |
20:05:59.06 |
-03:38:52.4 |
HIP 99024 |
26.02 |
| 2026-05-24 00:00 |
20:05:56.62 |
-03:38:42.4 |
HIP 99024 |
26.27 |
| 2026-05-24 12:00 |
20:05:54.14 |
-03:38:32.5 |
HIP 99024 |
26.53 |
| 2026-05-25 00:00 |
20:05:51.60 |
-03:38:22.9 |
HIP 99024 |
26.80 |
| 2026-05-25 12:00 |
20:05:49.03 |
-03:38:13.6 |
HIP 99024 |
27.08 |
| 2026-05-26 00:00 |
20:05:46.40 |
-03:38:04.5 |
HIP 99024 |
27.38 |
| 2026-05-26 12:00 |
20:05:43.73 |
-03:37:55.7 |
HIP 99024 |
27.68 |
| 2026-05-27 00:00 |
20:05:41.02 |
-03:37:47.2 |
HIP 99024 |
28.00 |
| 2026-05-27 12:00 |
20:05:38.26 |
-03:37:38.9 |
HIP 99024 |
28.33 |
| 2026-05-28 00:00 |
20:05:35.46 |
-03:37:30.8 |
HIP 99024 |
28.68 |
| 2026-05-28 12:00 |
20:05:32.61 |
-03:37:23.1 |
HIP 99024 |
29.03 |
| 2026-05-29 00:00 |
20:05:29.72 |
-03:37:15.6 |
HIP 99024 |
29.40 |
| 2026-05-29 12:00 |
20:05:26.78 |
-03:37:08.3 |
HIP 99024 |
29.79 |
| 2026-05-30 00:00 |
20:05:23.80 |
-03:37:01.3 |
HIP 99024 |
30.18 |
| 2026-05-30 12:00 |
20:05:20.78 |
-03:36:54.6 |
HIP 99024 |
30.59 |
| 2026-05-31 00:00 |
20:05:17.72 |
-03:36:48.2 |
HIP 99024 |
31.02 |
| 2026-05-31 12:00 |
20:05:14.61 |
-03:36:42.0 |
HIP 99024 |
31.46 |
| 2026-06-01 00:00 |
20:05:11.45 |
-03:36:36.1 |
HIP 99024 |
31.91 |
| 2026-06-01 12:00 |
20:05:08.26 |
-03:36:30.5 |
HIP 99024 |
32.38 |
| 2026-06-02 00:00 |
20:05:05.02 |
-03:36:25.1 |
HIP 99024 |
32.86 |