| Parameter |
Value |
| Designation |
250P/Larson |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-02-01T15:22:08.296320Z |
| Orbit solution date (soln_date, UTC) |
2026-03-31T09:42:38Z |
| Obs used |
550 |
| NEO |
- |
| M1 |
14.200 |
| K1 |
11.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-03-09.0000000 |
| e |
0.40746453 |
| q (au) |
2.212109 |
| a (au) |
3.733293 |
| i (deg) |
13.290220 |
| Ω (om, deg) |
73.721161 |
| ω (w, deg) |
45.007311 |
| M (ma, deg) |
215.078092 |
Magnitude
Scatter + Global Linear
$$
M_a = (18.493 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
18.493 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.692 |
| k |
0.930 |
| 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 |
14:26:57.38 |
+00:13:56.4 |
HIP 70595 |
9.96 |
| 2026-03-26 12:00 |
14:26:39.90 |
+00:15:24.2 |
HIP 70595 |
7.66 |
| 2026-03-27 00:00 |
14:26:22.16 |
+00:16:51.9 |
HIP 70595 |
7.79 |
| 2026-03-27 12:00 |
14:26:04.16 |
+00:18:19.4 |
HIP 70595 |
10.34 |
| 2026-03-28 00:00 |
14:25:45.92 |
+00:19:46.6 |
HIP 70595 |
14.10 |
| 2026-03-28 12:00 |
14:25:27.43 |
+00:21:13.6 |
HIP 70595 |
18.39 |
| 2026-03-29 00:00 |
14:25:08.69 |
+00:22:40.2 |
HIP 70595 |
22.95 |
| 2026-03-29 12:00 |
14:24:49.72 |
+00:24:06.6 |
HIP 70595 |
27.67 |
| 2026-03-30 00:00 |
14:24:30.51 |
+00:25:32.5 |
HIP 70364 |
29.67 |
| 2026-03-30 12:00 |
14:24:11.07 |
+00:26:58.1 |
HIP 70364 |
26.93 |
| 2026-03-31 00:00 |
14:23:51.40 |
+00:28:23.3 |
HIP 70364 |
24.94 |
| 2026-03-31 12:00 |
14:23:31.52 |
+00:29:48.1 |
HIP 70364 |
23.91 |
| 2026-04-01 00:00 |
14:23:11.42 |
+00:31:12.3 |
HIP 70364 |
24.00 |
| 2026-04-01 12:00 |
14:22:51.11 |
+00:32:36.1 |
HIP 70199 |
21.86 |
| 2026-04-02 00:00 |
14:22:30.59 |
+00:33:59.3 |
HIP 70199 |
17.24 |
| 2026-04-02 12:00 |
14:22:09.87 |
+00:35:22.0 |
HIP 70199 |
13.15 |
| 2026-04-03 00:00 |
14:21:48.95 |
+00:36:44.0 |
HIP 70199 |
10.30 |
| 2026-04-03 12:00 |
14:21:27.84 |
+00:38:05.5 |
HIP 70136 |
9.02 |
| 2026-04-04 00:00 |
14:21:06.54 |
+00:39:26.3 |
HIP 70136 |
8.33 |
| 2026-04-04 12:00 |
14:20:45.06 |
+00:40:46.4 |
HIP 70136 |
10.86 |
| 2026-04-05 00:00 |
14:20:23.40 |
+00:42:05.8 |
HIP 70136 |
15.11 |
| 2026-04-05 12:00 |
14:20:01.57 |
+00:43:24.5 |
HIP 70136 |
20.05 |
| 2026-04-06 00:00 |
14:19:39.57 |
+00:44:42.4 |
HIP 70022 |
21.65 |
| 2026-04-06 12:00 |
14:19:17.41 |
+00:45:59.6 |
HIP 70022 |
23.68 |
| 2026-04-07 00:00 |
14:18:55.09 |
+00:47:15.9 |
HIP 69884 |
24.68 |
| 2026-04-07 12:00 |
14:18:32.62 |
+00:48:31.3 |
HIP 69884 |
21.26 |
| 2026-04-08 00:00 |
14:18:10.00 |
+00:49:45.9 |
HIP 69884 |
19.01 |
| 2026-04-08 12:00 |
14:17:47.24 |
+00:50:59.5 |
HIP 69884 |
18.40 |
| 2026-04-09 00:00 |
14:17:24.35 |
+00:52:12.2 |
HIP 69884 |
19.62 |
| 2026-04-09 12:00 |
14:17:01.33 |
+00:53:23.9 |
HIP 69884 |
22.39 |
| 2026-04-10 00:00 |
14:16:38.18 |
+00:54:34.6 |
HIP 69632 |
23.74 |
| 2026-04-10 12:00 |
14:16:14.91 |
+00:55:44.3 |
HIP 69632 |
17.83 |
| 2026-04-11 00:00 |
14:15:51.54 |
+00:56:53.0 |
HIP 69632 |
11.90 |
| 2026-04-11 12:00 |
14:15:28.05 |
+00:58:00.5 |
HIP 69632 |
6.01 |
| 2026-04-12 00:00 |
14:15:04.46 |
+00:59:06.9 |
HIP 69632 |
1.44 |
| 2026-04-12 12:00 |
14:14:40.78 |
+01:00:12.2 |
HIP 69632 |
6.33 |
| 2026-04-13 00:00 |
14:14:17.01 |
+01:01:16.4 |
HIP 69632 |
12.29 |
| 2026-04-13 12:00 |
14:13:53.16 |
+01:02:19.3 |
HIP 69632 |
18.31 |
| 2026-04-14 00:00 |
14:13:29.22 |
+01:03:21.0 |
HIP 69497 |
20.91 |
| 2026-04-14 12:00 |
14:13:05.22 |
+01:04:21.4 |
HIP 69497 |
23.53 |
| 2026-04-15 00:00 |
14:12:41.15 |
+01:05:20.5 |
HIP 69340 |
23.96 |
| 2026-04-15 12:00 |
14:12:17.02 |
+01:06:18.4 |
HIP 69340 |
19.21 |
| 2026-04-16 00:00 |
14:11:52.84 |
+01:07:14.9 |
HIP 69340 |
15.46 |