| Parameter |
Value |
| Designation |
P/2015 B4 (Lemmon-PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-02-17T15:37:40.232640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:05Z |
| Obs used |
77 |
| NEO |
- |
| M1 |
15.200 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-11-20.0000000 |
| e |
0.56891192 |
| q (au) |
3.755337 |
| a (au) |
8.711300 |
| i (deg) |
1.742618 |
| Ω (om, deg) |
266.651081 |
| ω (w, deg) |
227.778528 |
| M (ma, deg) |
10.555113 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.526 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.526 |
| n |
2.000 |
| gf |
0.947 |
| gb |
-0.830 |
| k |
0.993 |
| δ90 |
1.000 |
| 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) |
| 2026-06-01 00:00 |
20:55:11.27 |
-16:06:16.9 |
HIP 103386 |
27.34 |
| 2026-06-01 12:00 |
20:55:08.55 |
-16:06:24.9 |
HIP 103386 |
27.96 |
| 2026-06-02 00:00 |
20:55:05.76 |
-16:06:33.1 |
HIP 103386 |
28.60 |
| 2026-06-02 12:00 |
20:55:02.89 |
-16:06:41.7 |
HIP 103386 |
29.25 |
| 2026-06-03 00:00 |
20:54:59.96 |
-16:06:50.6 |
HIP 103386 |
29.93 |
| 2026-06-03 12:00 |
20:54:56.96 |
-16:06:59.7 |
HIP 103386 |
30.62 |
| 2026-06-04 00:00 |
20:54:53.89 |
-16:07:09.2 |
HIP 103059 |
29.97 |
| 2026-06-04 12:00 |
20:54:50.74 |
-16:07:18.9 |
HIP 103059 |
29.20 |
| 2026-06-05 00:00 |
20:54:47.53 |
-16:07:28.9 |
HIP 103059 |
28.42 |
| 2026-06-05 12:00 |
20:54:44.25 |
-16:07:39.3 |
HIP 103059 |
27.62 |
| 2026-06-06 00:00 |
20:54:40.90 |
-16:07:49.9 |
HIP 103059 |
26.80 |
| 2026-06-06 12:00 |
20:54:37.48 |
-16:08:00.8 |
HIP 103059 |
25.97 |
| 2026-06-07 00:00 |
20:54:33.99 |
-16:08:12.0 |
HIP 103059 |
25.12 |
| 2026-06-07 12:00 |
20:54:30.44 |
-16:08:23.5 |
HIP 103059 |
24.25 |
| 2026-06-08 00:00 |
20:54:26.81 |
-16:08:35.2 |
HIP 103059 |
23.37 |
| 2026-06-08 12:00 |
20:54:23.12 |
-16:08:47.3 |
HIP 103059 |
22.48 |
| 2026-06-09 00:00 |
20:54:19.36 |
-16:08:59.7 |
HIP 103059 |
21.57 |
| 2026-06-09 12:00 |
20:54:15.53 |
-16:09:12.3 |
HIP 103059 |
20.64 |
| 2026-06-10 00:00 |
20:54:11.64 |
-16:09:25.2 |
HIP 103059 |
19.70 |
| 2026-06-10 12:00 |
20:54:07.67 |
-16:09:38.4 |
HIP 103059 |
18.74 |
| 2026-06-11 00:00 |
20:54:03.65 |
-16:09:51.9 |
HIP 103059 |
17.77 |
| 2026-06-11 12:00 |
20:53:59.55 |
-16:10:05.6 |
HIP 103059 |
16.79 |
| 2026-06-12 00:00 |
20:53:55.39 |
-16:10:19.7 |
HIP 103059 |
15.80 |
| 2026-06-12 12:00 |
20:53:51.17 |
-16:10:34.0 |
HIP 103059 |
14.79 |
| 2026-06-13 00:00 |
20:53:46.88 |
-16:10:48.6 |
HIP 103059 |
13.78 |
| 2026-06-13 12:00 |
20:53:42.52 |
-16:11:03.4 |
HIP 103059 |
12.75 |
| 2026-06-14 00:00 |
20:53:38.10 |
-16:11:18.6 |
HIP 103059 |
11.72 |
| 2026-06-14 12:00 |
20:53:33.62 |
-16:11:34.0 |
HIP 103059 |
10.69 |
| 2026-06-15 00:00 |
20:53:29.08 |
-16:11:49.6 |
HIP 103059 |
9.66 |
| 2026-06-15 12:00 |
20:53:24.47 |
-16:12:05.6 |
HIP 103059 |
8.64 |
| 2026-06-16 00:00 |
20:53:19.79 |
-16:12:21.8 |
HIP 103059 |
7.65 |
| 2026-06-16 12:00 |
20:53:15.06 |
-16:12:38.2 |
HIP 103059 |
6.69 |
| 2026-06-17 00:00 |
20:53:10.26 |
-16:12:55.0 |
HIP 103059 |
5.79 |
| 2026-06-17 12:00 |
20:53:05.41 |
-16:13:11.9 |
HIP 103059 |
5.02 |
| 2026-06-18 00:00 |
20:53:00.49 |
-16:13:29.2 |
HIP 103059 |
4.43 |
| 2026-06-18 12:00 |
20:52:55.51 |
-16:13:46.7 |
HIP 103059 |
4.12 |
| 2026-06-19 00:00 |
20:52:50.47 |
-16:14:04.4 |
HIP 103059 |
4.17 |
| 2026-06-19 12:00 |
20:52:45.38 |
-16:14:22.4 |
HIP 103059 |
4.58 |
| 2026-06-20 00:00 |
20:52:40.22 |
-16:14:40.7 |
HIP 103059 |
5.28 |
| 2026-06-20 12:00 |
20:52:35.01 |
-16:14:59.2 |
HIP 103059 |
6.17 |
| 2026-06-21 00:00 |
20:52:29.74 |
-16:15:17.9 |
HIP 103059 |
7.20 |
| 2026-06-21 12:00 |
20:52:24.41 |
-16:15:36.9 |
HIP 103059 |
8.32 |
| 2026-06-22 00:00 |
20:52:19.03 |
-16:15:56.1 |
HIP 103059 |
9.50 |