| 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) |
| 2026-03-26 00:00 |
06:38:54.60 |
-04:17:25.8 |
HIP 31760 |
4.64 |
| 2026-03-26 12:00 |
06:39:08.98 |
-04:14:32.8 |
HIP 31760 |
8.76 |
| 2026-03-27 00:00 |
06:39:23.63 |
-04:11:40.4 |
HIP 31760 |
13.26 |
| 2026-03-27 12:00 |
06:39:38.55 |
-04:08:48.8 |
HIP 31760 |
17.89 |
| 2026-03-28 00:00 |
06:39:53.74 |
-04:05:57.8 |
HIP 31921 |
22.40 |
| 2026-03-28 12:00 |
06:40:09.20 |
-04:03:07.6 |
HIP 31921 |
24.61 |
| 2026-03-29 00:00 |
06:40:24.92 |
-04:00:18.1 |
HIP 31921 |
27.47 |
| 2026-03-29 12:00 |
06:40:40.90 |
-03:57:29.3 |
HIP 31942 |
26.16 |
| 2026-03-30 00:00 |
06:40:57.14 |
-03:54:41.3 |
HIP 31942 |
24.19 |
| 2026-03-30 12:00 |
06:41:13.64 |
-03:51:54.1 |
HIP 32133 |
21.01 |
| 2026-03-31 00:00 |
06:41:30.41 |
-03:49:07.7 |
HIP 32133 |
16.79 |
| 2026-03-31 12:00 |
06:41:47.43 |
-03:46:22.1 |
HIP 32133 |
13.07 |
| 2026-04-01 00:00 |
06:42:04.70 |
-03:43:37.2 |
HIP 32133 |
10.48 |
| 2026-04-01 12:00 |
06:42:22.23 |
-03:40:53.3 |
HIP 32133 |
10.02 |
| 2026-04-02 00:00 |
06:42:40.01 |
-03:38:10.1 |
HIP 32133 |
11.99 |
| 2026-04-02 12:00 |
06:42:58.05 |
-03:35:27.8 |
HIP 32214 |
14.16 |
| 2026-04-03 00:00 |
06:43:16.33 |
-03:32:46.3 |
HIP 32214 |
9.48 |
| 2026-04-03 12:00 |
06:43:34.87 |
-03:30:05.8 |
HIP 32214 |
5.97 |
| 2026-04-04 00:00 |
06:43:53.65 |
-03:27:26.1 |
HIP 32214 |
6.27 |
| 2026-04-04 12:00 |
06:44:12.68 |
-03:24:47.3 |
HIP 32214 |
10.11 |
| 2026-04-05 00:00 |
06:44:31.95 |
-03:22:09.4 |
HIP 32214 |
15.04 |
| 2026-04-05 12:00 |
06:44:51.47 |
-03:19:32.4 |
HIP 32214 |
20.30 |
| 2026-04-06 00:00 |
06:45:11.23 |
-03:16:56.3 |
HIP 32214 |
25.74 |
| 2026-04-06 12:00 |
06:45:31.23 |
-03:14:21.2 |
HIP 32214 |
31.27 |
| 2026-04-07 00:00 |
06:45:51.47 |
-03:11:47.1 |
HIP 32573 |
29.67 |
| 2026-04-07 12:00 |
06:46:11.95 |
-03:09:13.9 |
HIP 32573 |
24.24 |
| 2026-04-08 00:00 |
06:46:32.67 |
-03:06:41.7 |
HIP 32573 |
18.92 |
| 2026-04-08 12:00 |
06:46:53.62 |
-03:04:10.4 |
HIP 32573 |
13.88 |
| 2026-04-09 00:00 |
06:47:14.81 |
-03:01:40.2 |
HIP 32573 |
9.68 |
| 2026-04-09 12:00 |
06:47:36.23 |
-02:59:11.0 |
HIP 32600 |
7.69 |
| 2026-04-10 00:00 |
06:47:57.88 |
-02:56:42.7 |
HIP 32600 |
5.86 |
| 2026-04-10 12:00 |
06:48:19.77 |
-02:54:15.5 |
HIP 32600 |
8.96 |
| 2026-04-11 00:00 |
06:48:41.89 |
-02:51:49.4 |
HIP 32600 |
14.10 |
| 2026-04-11 12:00 |
06:49:04.23 |
-02:49:24.3 |
HIP 32600 |
19.78 |
| 2026-04-12 00:00 |
06:49:26.80 |
-02:47:00.2 |
HIP 32600 |
25.68 |
| 2026-04-12 12:00 |
06:49:49.60 |
-02:44:37.3 |
HIP 32698 |
29.49 |
| 2026-04-13 00:00 |
06:50:12.62 |
-02:42:15.4 |
HIP 32936 |
28.58 |
| 2026-04-13 12:00 |
06:50:35.87 |
-02:39:54.6 |
HIP 32936 |
22.68 |
| 2026-04-14 00:00 |
06:50:59.34 |
-02:37:34.8 |
HIP 32936 |
17.01 |
| 2026-04-14 12:00 |
06:51:23.03 |
-02:35:16.3 |
HIP 32936 |
12.00 |
| 2026-04-15 00:00 |
06:51:46.94 |
-02:32:58.8 |
HIP 32936 |
8.93 |
| 2026-04-15 12:00 |
06:52:11.07 |
-02:30:42.4 |
HIP 33014 |
9.34 |
| 2026-04-16 00:00 |
06:52:35.42 |
-02:28:27.2 |
HIP 33014 |
2.85 |