| 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) |
| 2026-07-29 00:00 |
20:43:45.42 |
-16:47:42.8 |
HIP 102178 |
27.89 |
| 2026-07-29 12:00 |
20:43:37.58 |
-16:48:12.4 |
HIP 102178 |
26.11 |
| 2026-07-30 00:00 |
20:43:29.74 |
-16:48:42.0 |
HIP 102178 |
24.36 |
| 2026-07-30 12:00 |
20:43:21.90 |
-16:49:11.6 |
HIP 102178 |
22.64 |
| 2026-07-31 00:00 |
20:43:14.05 |
-16:49:41.3 |
HIP 102178 |
20.95 |
| 2026-07-31 12:00 |
20:43:06.21 |
-16:50:11.0 |
HIP 102178 |
19.32 |
| 2026-08-01 00:00 |
20:42:58.36 |
-16:50:40.6 |
HIP 102178 |
17.74 |
| 2026-08-01 12:00 |
20:42:50.51 |
-16:51:10.3 |
HIP 102178 |
16.25 |
| 2026-08-02 00:00 |
20:42:42.66 |
-16:51:40.0 |
HIP 102178 |
14.85 |
| 2026-08-02 12:00 |
20:42:34.81 |
-16:52:09.7 |
HIP 102178 |
13.60 |
| 2026-08-03 00:00 |
20:42:26.96 |
-16:52:39.4 |
HIP 102178 |
12.52 |
| 2026-08-03 12:00 |
20:42:19.12 |
-16:53:09.1 |
HIP 102178 |
11.66 |
| 2026-08-04 00:00 |
20:42:11.28 |
-16:53:38.8 |
HIP 102178 |
11.08 |
| 2026-08-04 12:00 |
20:42:03.44 |
-16:54:08.5 |
HIP 102178 |
10.82 |
| 2026-08-05 00:00 |
20:41:55.61 |
-16:54:38.1 |
HIP 102178 |
10.91 |
| 2026-08-05 12:00 |
20:41:47.79 |
-16:55:07.8 |
HIP 102178 |
11.33 |
| 2026-08-06 00:00 |
20:41:39.97 |
-16:55:37.4 |
HIP 102178 |
12.05 |
| 2026-08-06 12:00 |
20:41:32.16 |
-16:56:07.0 |
HIP 102178 |
13.02 |
| 2026-08-07 00:00 |
20:41:24.35 |
-16:56:36.6 |
HIP 102178 |
14.18 |
| 2026-08-07 12:00 |
20:41:16.56 |
-16:57:06.2 |
HIP 102178 |
15.50 |
| 2026-08-08 00:00 |
20:41:08.77 |
-16:57:35.7 |
HIP 102178 |
16.93 |
| 2026-08-08 12:00 |
20:41:01.00 |
-16:58:05.2 |
HIP 102178 |
18.45 |
| 2026-08-09 00:00 |
20:40:53.24 |
-16:58:34.7 |
HIP 102178 |
20.03 |
| 2026-08-09 12:00 |
20:40:45.49 |
-16:59:04.1 |
HIP 102178 |
21.67 |
| 2026-08-10 00:00 |
20:40:37.75 |
-16:59:33.5 |
HIP 102178 |
23.35 |
| 2026-08-10 12:00 |
20:40:30.03 |
-17:00:02.8 |
HIP 102178 |
25.06 |
| 2026-08-11 00:00 |
20:40:22.33 |
-17:00:32.1 |
HIP 101879 |
24.10 |
| 2026-08-11 12:00 |
20:40:14.63 |
-17:01:01.4 |
HIP 101879 |
22.22 |
| 2026-08-12 00:00 |
20:40:06.96 |
-17:01:30.5 |
HIP 101879 |
20.33 |
| 2026-08-12 12:00 |
20:39:59.30 |
-17:01:59.7 |
HIP 101879 |
18.46 |
| 2026-08-13 00:00 |
20:39:51.67 |
-17:02:28.7 |
HIP 101879 |
16.60 |
| 2026-08-13 12:00 |
20:39:44.05 |
-17:02:57.7 |
HIP 101879 |
14.75 |
| 2026-08-14 00:00 |
20:39:36.45 |
-17:03:26.6 |
HIP 101879 |
12.91 |
| 2026-08-14 12:00 |
20:39:28.88 |
-17:03:55.5 |
HIP 101879 |
11.09 |
| 2026-08-15 00:00 |
20:39:21.32 |
-17:04:24.2 |
HIP 101879 |
9.29 |
| 2026-08-15 12:00 |
20:39:13.79 |
-17:04:52.9 |
HIP 101879 |
7.54 |
| 2026-08-16 00:00 |
20:39:06.28 |
-17:05:21.6 |
HIP 101879 |
5.87 |
| 2026-08-16 12:00 |
20:38:58.80 |
-17:05:50.1 |
HIP 101879 |
4.35 |
| 2026-08-17 00:00 |
20:38:51.34 |
-17:06:18.5 |
HIP 101879 |
3.20 |
| 2026-08-17 12:00 |
20:38:43.91 |
-17:06:46.9 |
HIP 101879 |
2.89 |
| 2026-08-18 00:00 |
20:38:36.50 |
-17:07:15.1 |
HIP 101879 |
3.63 |
| 2026-08-18 12:00 |
20:38:29.12 |
-17:07:43.3 |
HIP 101879 |
4.97 |
| 2026-08-19 00:00 |
20:38:21.78 |
-17:08:11.3 |
HIP 101879 |
6.54 |