| 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) |
| 2026-09-20 00:00 |
14:01:16.88 |
-15:27:31.3 |
HIP 68606 |
32.05 |
| 2026-09-20 12:00 |
14:01:36.19 |
-15:28:47.1 |
HIP 68606 |
28.46 |
| 2026-09-21 00:00 |
14:01:55.55 |
-15:30:03.2 |
HIP 68606 |
25.28 |
| 2026-09-21 12:00 |
14:02:14.98 |
-15:31:19.7 |
HIP 68606 |
22.67 |
| 2026-09-22 00:00 |
14:02:34.47 |
-15:32:36.5 |
HIP 68606 |
20.87 |
| 2026-09-22 12:00 |
14:02:54.02 |
-15:33:53.6 |
HIP 68729 |
18.34 |
| 2026-09-23 00:00 |
14:03:13.64 |
-15:35:11.0 |
HIP 68729 |
14.32 |
| 2026-09-23 12:00 |
14:03:33.31 |
-15:36:28.7 |
HIP 68729 |
11.03 |
| 2026-09-24 00:00 |
14:03:53.03 |
-15:37:46.7 |
HIP 68729 |
9.30 |
| 2026-09-24 12:00 |
14:04:12.82 |
-15:39:05.0 |
HIP 68729 |
10.00 |
| 2026-09-25 00:00 |
14:04:32.67 |
-15:40:23.6 |
HIP 68729 |
12.75 |
| 2026-09-25 12:00 |
14:04:52.57 |
-15:41:42.5 |
HIP 68729 |
16.57 |
| 2026-09-26 00:00 |
14:05:12.53 |
-15:43:01.7 |
HIP 68729 |
20.90 |
| 2026-09-26 12:00 |
14:05:32.54 |
-15:44:21.1 |
HIP 68729 |
25.48 |
| 2026-09-27 00:00 |
14:05:52.61 |
-15:45:40.8 |
HIP 68900 |
28.13 |
| 2026-09-27 12:00 |
14:06:12.74 |
-15:47:00.8 |
HIP 68900 |
25.89 |
| 2026-09-28 00:00 |
14:06:32.92 |
-15:48:21.1 |
HIP 68900 |
24.49 |
| 2026-09-28 12:00 |
14:06:53.15 |
-15:49:41.6 |
HIP 68970 |
22.30 |
| 2026-09-29 00:00 |
14:07:13.44 |
-15:51:02.4 |
HIP 68970 |
20.39 |
| 2026-09-29 12:00 |
14:07:33.78 |
-15:52:23.4 |
HIP 68970 |
19.63 |
| 2026-09-30 00:00 |
14:07:54.17 |
-15:53:44.7 |
HIP 68970 |
20.16 |
| 2026-09-30 12:00 |
14:08:14.62 |
-15:55:06.2 |
HIP 68970 |
21.90 |
| 2026-10-01 00:00 |
14:08:35.12 |
-15:56:28.0 |
HIP 68970 |
24.59 |
| 2026-10-01 12:00 |
14:08:55.66 |
-15:57:50.0 |
HIP 68970 |
27.98 |
| 2026-10-02 00:00 |
14:09:16.26 |
-15:59:12.2 |
HIP 69269 |
29.49 |
| 2026-10-02 12:00 |
14:09:36.91 |
-16:00:34.7 |
HIP 69269 |
24.90 |
| 2026-10-03 00:00 |
14:09:57.61 |
-16:01:57.4 |
HIP 69269 |
20.55 |
| 2026-10-03 12:00 |
14:10:18.36 |
-16:03:20.3 |
HIP 69269 |
16.67 |
| 2026-10-04 00:00 |
14:10:39.16 |
-16:04:43.4 |
HIP 69269 |
13.67 |
| 2026-10-04 12:00 |
14:11:00.00 |
-16:06:06.8 |
HIP 69269 |
12.22 |
| 2026-10-05 00:00 |
14:11:20.89 |
-16:07:30.3 |
HIP 69269 |
12.88 |
| 2026-10-05 12:00 |
14:11:41.83 |
-16:08:54.1 |
HIP 69269 |
15.39 |
| 2026-10-06 00:00 |
14:12:02.82 |
-16:10:18.1 |
HIP 69269 |
19.04 |
| 2026-10-06 12:00 |
14:12:23.85 |
-16:11:42.2 |
HIP 69269 |
23.31 |
| 2026-10-07 00:00 |
14:12:44.93 |
-16:13:06.6 |
HIP 69269 |
27.92 |
| 2026-10-07 12:00 |
14:13:06.05 |
-16:14:31.1 |
HIP 69423 |
31.83 |
| 2026-10-08 00:00 |
14:13:27.21 |
-16:15:55.8 |
HIP 69423 |
31.37 |
| 2026-10-08 12:00 |
14:13:48.42 |
-16:17:20.7 |
HIP 69423 |
31.78 |
| 2026-10-09 00:00 |
14:14:09.68 |
-16:18:45.8 |
HIP 69683 |
27.85 |
| 2026-10-09 12:00 |
14:14:30.97 |
-16:20:11.0 |
HIP 69683 |
24.42 |
| 2026-10-10 00:00 |
14:14:52.30 |
-16:21:36.4 |
HIP 69683 |
21.75 |
| 2026-10-10 12:00 |
14:15:13.68 |
-16:23:02.0 |
HIP 69683 |
20.16 |
| 2026-10-11 00:00 |
14:15:35.09 |
-16:24:27.7 |
HIP 69683 |
19.91 |