| 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) |
| 2026-07-29 00:00 |
13:35:07.72 |
-14:00:50.4 |
HIP 66343 |
33.55 |
| 2026-07-29 12:00 |
13:35:17.01 |
-14:01:04.8 |
HIP 66343 |
33.20 |
| 2026-07-30 00:00 |
13:35:26.42 |
-14:01:20.0 |
HIP 66343 |
33.02 |
| 2026-07-30 12:00 |
13:35:35.96 |
-14:01:36.1 |
HIP 66343 |
33.01 |
| 2026-07-31 00:00 |
13:35:45.62 |
-14:01:52.9 |
HIP 66343 |
33.17 |
| 2026-07-31 12:00 |
13:35:55.41 |
-14:02:10.5 |
HIP 66510 |
32.33 |
| 2026-08-01 00:00 |
13:36:05.31 |
-14:02:28.9 |
HIP 66510 |
29.97 |
| 2026-08-01 12:00 |
13:36:15.34 |
-14:02:48.0 |
HIP 66510 |
27.60 |
| 2026-08-02 00:00 |
13:36:25.49 |
-14:03:08.0 |
HIP 66510 |
25.21 |
| 2026-08-02 12:00 |
13:36:35.76 |
-14:03:28.7 |
HIP 66510 |
22.81 |
| 2026-08-03 00:00 |
13:36:46.15 |
-14:03:50.2 |
HIP 66510 |
20.40 |
| 2026-08-03 12:00 |
13:36:56.66 |
-14:04:12.5 |
HIP 66510 |
18.00 |
| 2026-08-04 00:00 |
13:37:07.29 |
-14:04:35.5 |
HIP 66510 |
15.62 |
| 2026-08-04 12:00 |
13:37:18.04 |
-14:04:59.3 |
HIP 66510 |
13.30 |
| 2026-08-05 00:00 |
13:37:28.91 |
-14:05:23.8 |
HIP 66510 |
11.10 |
| 2026-08-05 12:00 |
13:37:39.90 |
-14:05:49.1 |
HIP 66510 |
9.11 |
| 2026-08-06 00:00 |
13:37:51.00 |
-14:06:15.2 |
HIP 66510 |
7.56 |
| 2026-08-06 12:00 |
13:38:02.22 |
-14:06:42.0 |
HIP 66510 |
6.78 |
| 2026-08-07 00:00 |
13:38:13.55 |
-14:07:09.6 |
HIP 66510 |
7.07 |
| 2026-08-07 12:00 |
13:38:25.01 |
-14:07:37.9 |
HIP 66510 |
8.35 |
| 2026-08-08 00:00 |
13:38:36.58 |
-14:08:06.9 |
HIP 66510 |
10.28 |
| 2026-08-08 12:00 |
13:38:48.26 |
-14:08:36.7 |
HIP 66510 |
12.59 |
| 2026-08-09 00:00 |
13:39:00.06 |
-14:09:07.2 |
HIP 66510 |
15.11 |
| 2026-08-09 12:00 |
13:39:11.97 |
-14:09:38.4 |
HIP 66510 |
17.77 |
| 2026-08-10 00:00 |
13:39:23.99 |
-14:10:10.4 |
HIP 66510 |
20.54 |
| 2026-08-10 12:00 |
13:39:36.13 |
-14:10:43.0 |
HIP 66510 |
23.38 |
| 2026-08-11 00:00 |
13:39:48.38 |
-14:11:16.4 |
HIP 66510 |
26.27 |
| 2026-08-11 12:00 |
13:40:00.74 |
-14:11:50.5 |
HIP 66510 |
29.22 |
| 2026-08-12 00:00 |
13:40:13.21 |
-14:12:25.3 |
HIP 66834 |
26.89 |
| 2026-08-12 12:00 |
13:40:25.80 |
-14:13:00.9 |
HIP 66834 |
23.93 |
| 2026-08-13 00:00 |
13:40:38.49 |
-14:13:37.1 |
HIP 66834 |
20.99 |
| 2026-08-13 12:00 |
13:40:51.29 |
-14:14:14.0 |
HIP 66834 |
18.09 |
| 2026-08-14 00:00 |
13:41:04.21 |
-14:14:51.6 |
HIP 66834 |
15.26 |
| 2026-08-14 12:00 |
13:41:17.22 |
-14:15:29.9 |
HIP 66834 |
12.57 |
| 2026-08-15 00:00 |
13:41:30.35 |
-14:16:08.8 |
HIP 66834 |
10.18 |
| 2026-08-15 12:00 |
13:41:43.58 |
-14:16:48.4 |
HIP 66834 |
8.37 |
| 2026-08-16 00:00 |
13:41:56.92 |
-14:17:28.8 |
HIP 66834 |
7.60 |
| 2026-08-16 12:00 |
13:42:10.37 |
-14:18:09.7 |
HIP 66834 |
8.20 |
| 2026-08-17 00:00 |
13:42:23.92 |
-14:18:51.3 |
HIP 66834 |
9.96 |
| 2026-08-17 12:00 |
13:42:37.57 |
-14:19:33.6 |
HIP 66834 |
12.41 |
| 2026-08-18 00:00 |
13:42:51.32 |
-14:20:16.6 |
HIP 66973 |
12.02 |
| 2026-08-18 12:00 |
13:43:05.18 |
-14:21:00.1 |
HIP 66973 |
9.64 |
| 2026-08-19 00:00 |
13:43:19.14 |
-14:21:44.4 |
HIP 66973 |
8.06 |