C/2004 C1 (Larsen)
| 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) |
| 2026-02-03 00:00 |
19:56:01.33 |
-05:04:36.6 |
HIP 98257 |
29.52 |
| 2026-02-03 12:00 |
19:56:07.89 |
-05:04:16.1 |
HIP 98257 |
28.01 |
| 2026-02-04 00:00 |
19:56:14.43 |
-05:03:55.5 |
HIP 98257 |
26.53 |
| 2026-02-04 12:00 |
19:56:20.96 |
-05:03:34.7 |
HIP 98257 |
25.07 |
| 2026-02-05 00:00 |
19:56:27.47 |
-05:03:13.8 |
HIP 98257 |
23.64 |
| 2026-02-05 12:00 |
19:56:33.97 |
-05:02:52.7 |
HIP 98257 |
22.25 |
| 2026-02-06 00:00 |
19:56:40.45 |
-05:02:31.4 |
HIP 98257 |
20.91 |
| 2026-02-06 12:00 |
19:56:46.92 |
-05:02:10.0 |
HIP 98257 |
19.61 |
| 2026-02-07 00:00 |
19:56:53.37 |
-05:01:48.4 |
HIP 98257 |
18.38 |
| 2026-02-07 12:00 |
19:56:59.81 |
-05:01:26.6 |
HIP 98257 |
17.22 |
| 2026-02-08 00:00 |
19:57:06.22 |
-05:01:04.7 |
HIP 98257 |
16.15 |
| 2026-02-08 12:00 |
19:57:12.62 |
-05:00:42.7 |
HIP 98257 |
15.18 |
| 2026-02-09 00:00 |
19:57:19.01 |
-05:00:20.5 |
HIP 98257 |
14.35 |
| 2026-02-09 12:00 |
19:57:25.37 |
-04:59:58.1 |
HIP 98257 |
13.66 |
| 2026-02-10 00:00 |
19:57:31.72 |
-04:59:35.6 |
HIP 98257 |
13.14 |
| 2026-02-10 12:00 |
19:57:38.05 |
-04:59:12.9 |
HIP 98257 |
12.82 |
| 2026-02-11 00:00 |
19:57:44.35 |
-04:58:50.1 |
HIP 98257 |
12.70 |
| 2026-02-11 12:00 |
19:57:50.64 |
-04:58:27.1 |
HIP 98257 |
12.78 |
| 2026-02-12 00:00 |
19:57:56.91 |
-04:58:04.0 |
HIP 98257 |
13.07 |
| 2026-02-12 12:00 |
19:58:03.16 |
-04:57:40.7 |
HIP 98257 |
13.55 |
| 2026-02-13 00:00 |
19:58:09.39 |
-04:57:17.3 |
HIP 98257 |
14.19 |
| 2026-02-13 12:00 |
19:58:15.60 |
-04:56:53.8 |
HIP 98257 |
14.98 |
| 2026-02-14 00:00 |
19:58:21.78 |
-04:56:30.1 |
HIP 98257 |
15.89 |
| 2026-02-14 12:00 |
19:58:27.95 |
-04:56:06.3 |
HIP 98257 |
16.90 |
| 2026-02-15 00:00 |
19:58:34.09 |
-04:55:42.4 |
HIP 98257 |
17.99 |
| 2026-02-15 12:00 |
19:58:40.21 |
-04:55:18.3 |
HIP 98257 |
19.15 |
| 2026-02-16 00:00 |
19:58:46.30 |
-04:54:54.1 |
HIP 98257 |
20.36 |
| 2026-02-16 12:00 |
19:58:52.38 |
-04:54:29.7 |
HIP 98257 |
21.62 |
| 2026-02-17 00:00 |
19:58:58.43 |
-04:54:05.3 |
HIP 98257 |
22.91 |
| 2026-02-17 12:00 |
19:59:04.45 |
-04:53:40.7 |
HIP 98257 |
24.23 |
| 2026-02-18 00:00 |
19:59:10.45 |
-04:53:16.0 |
HIP 98257 |
25.58 |
| 2026-02-18 12:00 |
19:59:16.43 |
-04:52:51.2 |
HIP 98257 |
26.94 |
| 2026-02-19 00:00 |
19:59:22.38 |
-04:52:26.2 |
HIP 98257 |
28.32 |
| 2026-02-19 12:00 |
19:59:28.30 |
-04:52:01.2 |
HIP 98257 |
29.72 |
| 2026-02-20 00:00 |
19:59:34.20 |
-04:51:36.0 |
HIP 98257 |
31.12 |
| 2026-02-20 12:00 |
19:59:40.08 |
-04:51:10.7 |
HIP 98257 |
32.52 |
| 2026-02-21 00:00 |
19:59:45.92 |
-04:50:45.3 |
HIP 98257 |
33.94 |
| 2026-02-21 12:00 |
19:59:51.74 |
-04:50:19.8 |
HIP 98642 |
34.56 |
| 2026-02-22 00:00 |
19:59:57.53 |
-04:49:54.2 |
HIP 98642 |
33.11 |
| 2026-02-22 12:00 |
20:00:03.30 |
-04:49:28.5 |
HIP 98642 |
31.67 |
| 2026-02-23 00:00 |
20:00:09.04 |
-04:49:02.7 |
HIP 98642 |
30.24 |
| 2026-02-23 12:00 |
20:00:14.74 |
-04:48:36.8 |
HIP 98642 |
28.83 |
| 2026-02-24 00:00 |
20:00:20.42 |
-04:48:10.8 |
HIP 98642 |
27.43 |