264P/Larsen
| 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) |
| 2026-02-03 00:00 |
06:40:24.25 |
-09:01:20.6 |
HIP 32064 |
24.35 |
| 2026-02-03 12:00 |
06:40:08.79 |
-08:59:28.0 |
HIP 31822 |
26.27 |
| 2026-02-04 00:00 |
06:39:53.56 |
-08:57:33.3 |
HIP 31822 |
26.26 |
| 2026-02-04 12:00 |
06:39:38.58 |
-08:55:36.5 |
HIP 31902 |
26.74 |
| 2026-02-05 00:00 |
06:39:23.84 |
-08:53:37.6 |
HIP 31693 |
23.85 |
| 2026-02-05 12:00 |
06:39:09.35 |
-08:51:36.7 |
HIP 31693 |
19.86 |
| 2026-02-06 00:00 |
06:38:55.10 |
-08:49:33.8 |
HIP 31693 |
16.00 |
| 2026-02-06 12:00 |
06:38:41.11 |
-08:47:28.9 |
HIP 31693 |
12.34 |
| 2026-02-07 00:00 |
06:38:27.37 |
-08:45:22.1 |
HIP 31693 |
9.06 |
| 2026-02-07 12:00 |
06:38:13.89 |
-08:43:13.4 |
HIP 31693 |
6.70 |
| 2026-02-08 00:00 |
06:38:00.66 |
-08:41:02.8 |
HIP 31693 |
6.30 |
| 2026-02-08 12:00 |
06:37:47.70 |
-08:38:50.4 |
HIP 31693 |
8.11 |
| 2026-02-09 00:00 |
06:37:35.01 |
-08:36:36.1 |
HIP 31693 |
11.05 |
| 2026-02-09 12:00 |
06:37:22.58 |
-08:34:20.1 |
HIP 31693 |
14.42 |
| 2026-02-10 00:00 |
06:37:10.43 |
-08:32:02.3 |
HIP 31693 |
17.96 |
| 2026-02-10 12:00 |
06:36:58.54 |
-08:29:42.8 |
HIP 31656 |
17.64 |
| 2026-02-11 00:00 |
06:36:46.93 |
-08:27:21.5 |
HIP 31656 |
17.30 |
| 2026-02-11 12:00 |
06:36:35.60 |
-08:24:58.7 |
HIP 31656 |
17.67 |
| 2026-02-12 00:00 |
06:36:24.54 |
-08:22:34.2 |
HIP 31656 |
18.70 |
| 2026-02-12 12:00 |
06:36:13.77 |
-08:20:08.1 |
HIP 31656 |
20.27 |
| 2026-02-13 00:00 |
06:36:03.28 |
-08:17:40.5 |
HIP 31656 |
22.24 |
| 2026-02-13 12:00 |
06:35:53.07 |
-08:15:11.3 |
HIP 31656 |
24.51 |
| 2026-02-14 00:00 |
06:35:43.15 |
-08:12:40.7 |
HIP 31352 |
24.49 |
| 2026-02-14 12:00 |
06:35:33.53 |
-08:10:08.6 |
HIP 31352 |
21.04 |
| 2026-02-15 00:00 |
06:35:24.19 |
-08:07:35.0 |
HIP 31352 |
17.65 |
| 2026-02-15 12:00 |
06:35:15.14 |
-08:05:00.1 |
HIP 31352 |
14.33 |
| 2026-02-16 00:00 |
06:35:06.39 |
-08:02:23.8 |
HIP 31352 |
11.12 |
| 2026-02-16 12:00 |
06:34:57.94 |
-07:59:46.2 |
HIP 31352 |
8.12 |
| 2026-02-17 00:00 |
06:34:49.78 |
-07:57:07.4 |
HIP 31352 |
5.62 |
| 2026-02-17 12:00 |
06:34:41.92 |
-07:54:27.2 |
HIP 31352 |
4.48 |
| 2026-02-18 00:00 |
06:34:34.36 |
-07:51:45.9 |
HIP 31352 |
5.56 |
| 2026-02-18 12:00 |
06:34:27.11 |
-07:49:03.3 |
HIP 31352 |
7.96 |
| 2026-02-19 00:00 |
06:34:20.15 |
-07:46:19.6 |
HIP 31352 |
10.83 |
| 2026-02-19 12:00 |
06:34:13.51 |
-07:43:34.8 |
HIP 31352 |
13.85 |
| 2026-02-20 00:00 |
06:34:07.16 |
-07:40:49.0 |
HIP 31352 |
16.94 |
| 2026-02-20 12:00 |
06:34:01.12 |
-07:38:02.0 |
HIP 31352 |
20.05 |
| 2026-02-21 00:00 |
06:33:55.39 |
-07:35:14.1 |
HIP 31199 |
18.49 |
| 2026-02-21 12:00 |
06:33:49.97 |
-07:32:25.2 |
HIP 31199 |
16.65 |
| 2026-02-22 00:00 |
06:33:44.86 |
-07:29:35.3 |
HIP 31199 |
15.30 |
| 2026-02-22 12:00 |
06:33:40.05 |
-07:26:44.6 |
HIP 31285 |
14.54 |
| 2026-02-23 00:00 |
06:33:35.56 |
-07:23:52.9 |
HIP 31285 |
11.75 |
| 2026-02-23 12:00 |
06:33:31.37 |
-07:21:00.4 |
HIP 31285 |
9.12 |
| 2026-02-24 00:00 |
06:33:27.50 |
-07:18:07.2 |
HIP 31285 |
6.80 |