| 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) |
| 2026-09-20 00:00 |
20:32:01.72 |
-17:32:50.9 |
HIP 101244 |
26.45 |
| 2026-09-20 12:00 |
20:31:57.63 |
-17:33:07.6 |
HIP 101244 |
26.36 |
| 2026-09-21 00:00 |
20:31:53.61 |
-17:33:24.0 |
HIP 101244 |
26.31 |
| 2026-09-21 12:00 |
20:31:49.66 |
-17:33:40.2 |
HIP 101244 |
26.30 |
| 2026-09-22 00:00 |
20:31:45.78 |
-17:33:56.2 |
HIP 101244 |
26.33 |
| 2026-09-22 12:00 |
20:31:41.96 |
-17:34:11.9 |
HIP 101244 |
26.39 |
| 2026-09-23 00:00 |
20:31:38.22 |
-17:34:27.3 |
HIP 101244 |
26.49 |
| 2026-09-23 12:00 |
20:31:34.54 |
-17:34:42.6 |
HIP 101244 |
26.61 |
| 2026-09-24 00:00 |
20:31:30.93 |
-17:34:57.5 |
HIP 101244 |
26.76 |
| 2026-09-24 12:00 |
20:31:27.40 |
-17:35:12.3 |
HIP 101244 |
26.94 |
| 2026-09-25 00:00 |
20:31:23.94 |
-17:35:26.8 |
HIP 101244 |
27.14 |
| 2026-09-25 12:00 |
20:31:20.54 |
-17:35:41.0 |
HIP 101244 |
27.37 |
| 2026-09-26 00:00 |
20:31:17.22 |
-17:35:55.0 |
HIP 101244 |
27.61 |
| 2026-09-26 12:00 |
20:31:13.97 |
-17:36:08.8 |
HIP 101244 |
27.87 |
| 2026-09-27 00:00 |
20:31:10.79 |
-17:36:22.3 |
HIP 101244 |
28.14 |
| 2026-09-27 12:00 |
20:31:07.68 |
-17:36:35.5 |
HIP 101244 |
28.43 |
| 2026-09-28 00:00 |
20:31:04.65 |
-17:36:48.5 |
HIP 101249 |
28.50 |
| 2026-09-28 12:00 |
20:31:01.68 |
-17:37:01.3 |
HIP 101249 |
28.41 |
| 2026-09-29 00:00 |
20:30:58.79 |
-17:37:13.8 |
HIP 101249 |
28.35 |
| 2026-09-29 12:00 |
20:30:55.98 |
-17:37:26.0 |
HIP 101249 |
28.30 |
| 2026-09-30 00:00 |
20:30:53.23 |
-17:37:38.0 |
HIP 101249 |
28.27 |
| 2026-09-30 12:00 |
20:30:50.56 |
-17:37:49.7 |
HIP 101249 |
28.26 |
| 2026-10-01 00:00 |
20:30:47.97 |
-17:38:01.2 |
HIP 101249 |
28.26 |
| 2026-10-01 12:00 |
20:30:45.45 |
-17:38:12.4 |
HIP 101036 |
28.13 |
| 2026-10-02 00:00 |
20:30:43.00 |
-17:38:23.4 |
HIP 101036 |
27.68 |
| 2026-10-02 12:00 |
20:30:40.63 |
-17:38:34.1 |
HIP 101036 |
27.26 |
| 2026-10-03 00:00 |
20:30:38.33 |
-17:38:44.5 |
HIP 101036 |
26.86 |
| 2026-10-03 12:00 |
20:30:36.11 |
-17:38:54.7 |
HIP 101036 |
26.47 |
| 2026-10-04 00:00 |
20:30:33.96 |
-17:39:04.6 |
HIP 101040 |
25.95 |
| 2026-10-04 12:00 |
20:30:31.89 |
-17:39:14.3 |
HIP 101040 |
25.45 |
| 2026-10-05 00:00 |
20:30:29.89 |
-17:39:23.7 |
HIP 101040 |
24.96 |
| 2026-10-05 12:00 |
20:30:27.97 |
-17:39:32.8 |
HIP 101040 |
24.49 |
| 2026-10-06 00:00 |
20:30:26.13 |
-17:39:41.7 |
HIP 101040 |
24.04 |
| 2026-10-06 12:00 |
20:30:24.36 |
-17:39:50.3 |
HIP 101040 |
23.61 |
| 2026-10-07 00:00 |
20:30:22.67 |
-17:39:58.6 |
HIP 101040 |
23.20 |
| 2026-10-07 12:00 |
20:30:21.06 |
-17:40:06.7 |
HIP 101040 |
22.80 |
| 2026-10-08 00:00 |
20:30:19.52 |
-17:40:14.4 |
HIP 101040 |
22.42 |
| 2026-10-08 12:00 |
20:30:18.07 |
-17:40:22.0 |
HIP 101040 |
22.07 |
| 2026-10-09 00:00 |
20:30:16.69 |
-17:40:29.2 |
HIP 101040 |
21.73 |
| 2026-10-09 12:00 |
20:30:15.38 |
-17:40:36.2 |
HIP 101040 |
21.40 |
| 2026-10-10 00:00 |
20:30:14.16 |
-17:40:42.9 |
HIP 101040 |
21.10 |
| 2026-10-10 12:00 |
20:30:13.01 |
-17:40:49.3 |
HIP 101040 |
20.81 |
| 2026-10-11 00:00 |
20:30:11.94 |
-17:40:55.4 |
HIP 101040 |
20.54 |