| Parameter |
Value |
| Designation |
264P/Larsen |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2004-03-13T06:19:55.698240Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:10Z |
| Obs used |
112 |
| NEO |
- |
| M1 |
16.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2005-11-25.0000000 |
| e |
0.37373545 |
| q (au) |
2.438280 |
| a (au) |
3.893371 |
| i (deg) |
25.148268 |
| Ω (om, deg) |
220.967548 |
| ω (w, deg) |
346.619062 |
| M (ma, deg) |
79.766687 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.735 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.735 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
09:06:11.62 |
-02:58:28.6 |
HIP 44696 |
22.94 |
| 2026-07-29 12:00 |
09:06:57.97 |
-03:01:00.6 |
HIP 44696 |
25.99 |
| 2026-07-30 00:00 |
09:07:44.35 |
-03:03:33.8 |
HIP 44696 |
33.27 |
| 2026-07-30 12:00 |
09:08:30.75 |
-03:06:08.2 |
HIP 45047 |
35.98 |
| 2026-07-31 00:00 |
09:09:17.19 |
-03:08:43.7 |
HIP 45047 |
25.16 |
| 2026-07-31 12:00 |
09:10:03.66 |
-03:11:20.5 |
HIP 45047 |
15.91 |
| 2026-08-01 00:00 |
09:10:50.16 |
-03:13:58.4 |
HIP 45047 |
12.47 |
| 2026-08-01 12:00 |
09:11:36.68 |
-03:16:37.5 |
HIP 45134 |
8.40 |
| 2026-08-02 00:00 |
09:12:23.24 |
-03:19:17.7 |
HIP 45134 |
14.03 |
| 2026-08-02 12:00 |
09:13:09.82 |
-03:21:59.2 |
HIP 45203 |
21.23 |
| 2026-08-03 00:00 |
09:13:56.44 |
-03:24:41.8 |
HIP 45398 |
28.16 |
| 2026-08-03 12:00 |
09:14:43.08 |
-03:27:25.5 |
HIP 45398 |
20.31 |
| 2026-08-04 00:00 |
09:15:29.75 |
-03:30:10.5 |
HIP 45398 |
17.82 |
| 2026-08-04 12:00 |
09:16:16.45 |
-03:32:56.5 |
HIP 45398 |
22.55 |
| 2026-08-05 00:00 |
09:17:03.17 |
-03:35:43.8 |
HIP 45621 |
18.06 |
| 2026-08-05 12:00 |
09:17:49.92 |
-03:38:32.1 |
HIP 45621 |
15.37 |
| 2026-08-06 00:00 |
09:18:36.70 |
-03:41:21.6 |
HIP 45621 |
20.86 |
| 2026-08-06 12:00 |
09:19:23.50 |
-03:44:12.3 |
HIP 45621 |
30.39 |
| 2026-08-07 00:00 |
09:20:10.33 |
-03:47:04.1 |
HIP 45889 |
33.31 |
| 2026-08-07 12:00 |
09:20:57.19 |
-03:49:57.0 |
HIP 45889 |
25.77 |
| 2026-08-08 00:00 |
09:21:44.07 |
-03:52:51.1 |
HIP 45889 |
22.52 |
| 2026-08-08 12:00 |
09:22:30.98 |
-03:55:46.3 |
HIP 45889 |
25.29 |
| 2026-08-09 00:00 |
09:23:17.90 |
-03:58:42.6 |
HIP 46165 |
29.98 |
| 2026-08-09 12:00 |
09:24:04.86 |
-04:01:40.0 |
HIP 46165 |
19.49 |
| 2026-08-10 00:00 |
09:24:51.84 |
-04:04:38.6 |
HIP 46165 |
12.33 |
| 2026-08-10 12:00 |
09:25:38.84 |
-04:07:38.2 |
HIP 46165 |
14.71 |
| 2026-08-11 00:00 |
09:26:25.86 |
-04:10:39.0 |
HIP 46165 |
23.94 |
| 2026-08-11 12:00 |
09:27:12.90 |
-04:13:40.8 |
HIP 46378 |
20.23 |
| 2026-08-12 00:00 |
09:27:59.97 |
-04:16:43.7 |
HIP 46378 |
19.17 |
| 2026-08-12 12:00 |
09:28:47.05 |
-04:19:47.8 |
HIP 46543 |
12.37 |
| 2026-08-13 00:00 |
09:29:34.16 |
-04:22:52.9 |
HIP 46543 |
8.10 |
| 2026-08-13 12:00 |
09:30:21.29 |
-04:25:59.1 |
HIP 46543 |
16.54 |
| 2026-08-14 00:00 |
09:31:08.43 |
-04:29:06.3 |
HIP 46780 |
13.77 |
| 2026-08-14 12:00 |
09:31:55.59 |
-04:32:14.6 |
HIP 46780 |
7.61 |
| 2026-08-15 00:00 |
09:32:42.78 |
-04:35:24.0 |
HIP 46886 |
13.59 |
| 2026-08-15 12:00 |
09:33:29.98 |
-04:38:34.4 |
HIP 46886 |
14.25 |
| 2026-08-16 00:00 |
09:34:17.19 |
-04:41:45.8 |
HIP 47027 |
16.17 |
| 2026-08-16 12:00 |
09:35:04.43 |
-04:44:58.3 |
HIP 47027 |
8.39 |
| 2026-08-17 00:00 |
09:35:51.68 |
-04:48:11.8 |
HIP 47027 |
13.30 |
| 2026-08-17 12:00 |
09:36:38.95 |
-04:51:26.3 |
HIP 47027 |
24.12 |
| 2026-08-18 00:00 |
09:37:26.23 |
-04:54:41.9 |
HIP 47284 |
19.09 |
| 2026-08-18 12:00 |
09:38:13.53 |
-04:57:58.4 |
HIP 47284 |
12.02 |
| 2026-08-19 00:00 |
09:39:00.84 |
-05:01:16.0 |
HIP 47284 |
14.95 |