200P/Larsen
| Parameter |
Value |
| Designation |
200P/Larsen |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2008-08-25T00:09:36.175680Z |
| Orbit solution date (soln_date, UTC) |
2022-02-03T20:43:19Z |
| Obs used |
610 |
| NEO |
- |
| M1 |
7.000 |
| K1 |
17.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-01-06.0000000 |
| e |
0.33323678 |
| q (au) |
3.272199 |
| a (au) |
4.907588 |
| i (deg) |
12.121060 |
| Ω (om, deg) |
234.819218 |
| ω (w, deg) |
133.693288 |
| M (ma, deg) |
338.966942 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.603 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.603 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.501 |
| k |
1.000 |
| 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) |
| 2026-02-03 00:00 |
14:07:48.53 |
-19:03:47.2 |
HIP 68968 |
16.14 |
| 2026-02-03 12:00 |
14:07:51.97 |
-19:04:15.6 |
HIP 68968 |
16.24 |
| 2026-02-04 00:00 |
14:07:55.25 |
-19:04:43.2 |
HIP 68968 |
16.38 |
| 2026-02-04 12:00 |
14:07:58.38 |
-19:05:10.0 |
HIP 68968 |
16.55 |
| 2026-02-05 00:00 |
14:08:01.36 |
-19:05:36.0 |
HIP 69126 |
16.65 |
| 2026-02-05 12:00 |
14:08:04.18 |
-19:06:01.2 |
HIP 69126 |
15.86 |
| 2026-02-06 00:00 |
14:08:06.84 |
-19:06:25.6 |
HIP 69126 |
15.11 |
| 2026-02-06 12:00 |
14:08:09.35 |
-19:06:49.1 |
HIP 69126 |
14.40 |
| 2026-02-07 00:00 |
14:08:11.70 |
-19:07:11.9 |
HIP 69126 |
13.73 |
| 2026-02-07 12:00 |
14:08:13.90 |
-19:07:33.8 |
HIP 69126 |
13.10 |
| 2026-02-08 00:00 |
14:08:15.94 |
-19:07:54.8 |
HIP 69126 |
12.50 |
| 2026-02-08 12:00 |
14:08:17.82 |
-19:08:15.1 |
HIP 69126 |
11.95 |
| 2026-02-09 00:00 |
14:08:19.54 |
-19:08:34.5 |
HIP 69126 |
11.43 |
| 2026-02-09 12:00 |
14:08:21.10 |
-19:08:53.0 |
HIP 69126 |
10.95 |
| 2026-02-10 00:00 |
14:08:22.51 |
-19:09:10.7 |
HIP 69126 |
10.51 |
| 2026-02-10 12:00 |
14:08:23.75 |
-19:09:27.6 |
HIP 69126 |
10.12 |
| 2026-02-11 00:00 |
14:08:24.84 |
-19:09:43.6 |
HIP 69126 |
9.76 |
| 2026-02-11 12:00 |
14:08:25.77 |
-19:09:58.7 |
HIP 69126 |
9.44 |
| 2026-02-12 00:00 |
14:08:26.53 |
-19:10:13.0 |
HIP 69126 |
9.17 |
| 2026-02-12 12:00 |
14:08:27.14 |
-19:10:26.4 |
HIP 69126 |
8.93 |
| 2026-02-13 00:00 |
14:08:27.59 |
-19:10:38.9 |
HIP 69126 |
8.74 |
| 2026-02-13 12:00 |
14:08:27.87 |
-19:10:50.6 |
HIP 69126 |
8.59 |
| 2026-02-14 00:00 |
14:08:28.00 |
-19:11:01.3 |
HIP 69126 |
8.48 |
| 2026-02-14 12:00 |
14:08:27.96 |
-19:11:11.2 |
HIP 69126 |
8.42 |
| 2026-02-15 00:00 |
14:08:27.76 |
-19:11:20.3 |
HIP 69126 |
8.40 |
| 2026-02-15 12:00 |
14:08:27.40 |
-19:11:28.4 |
HIP 69126 |
8.43 |
| 2026-02-16 00:00 |
14:08:26.88 |
-19:11:35.6 |
HIP 69126 |
8.49 |
| 2026-02-16 12:00 |
14:08:26.20 |
-19:11:41.9 |
HIP 69126 |
8.61 |
| 2026-02-17 00:00 |
14:08:25.36 |
-19:11:47.4 |
HIP 69126 |
8.76 |
| 2026-02-17 12:00 |
14:08:24.36 |
-19:11:51.9 |
HIP 69126 |
8.96 |
| 2026-02-18 00:00 |
14:08:23.19 |
-19:11:55.6 |
HIP 69126 |
9.20 |
| 2026-02-18 12:00 |
14:08:21.86 |
-19:11:58.3 |
HIP 69126 |
9.49 |
| 2026-02-19 00:00 |
14:08:20.37 |
-19:12:00.1 |
HIP 69126 |
9.82 |
| 2026-02-19 12:00 |
14:08:18.73 |
-19:12:01.0 |
HIP 69126 |
10.19 |
| 2026-02-20 00:00 |
14:08:16.92 |
-19:12:01.0 |
HIP 69126 |
10.60 |
| 2026-02-20 12:00 |
14:08:14.95 |
-19:12:00.1 |
HIP 69126 |
11.06 |
| 2026-02-21 00:00 |
14:08:12.81 |
-19:11:58.3 |
HIP 69126 |
11.55 |
| 2026-02-21 12:00 |
14:08:10.52 |
-19:11:55.5 |
HIP 69126 |
12.09 |
| 2026-02-22 00:00 |
14:08:08.07 |
-19:11:51.8 |
HIP 69126 |
12.66 |
| 2026-02-22 12:00 |
14:08:05.46 |
-19:11:47.2 |
HIP 69126 |
13.28 |
| 2026-02-23 00:00 |
14:08:02.69 |
-19:11:41.7 |
HIP 68968 |
13.62 |
| 2026-02-23 12:00 |
14:07:59.76 |
-19:11:35.3 |
HIP 68968 |
13.03 |
| 2026-02-24 00:00 |
14:07:56.67 |
-19:11:27.9 |
HIP 68968 |
12.43 |