| Parameter |
Value |
| Designation |
457P/Lemmon-PANSTARRS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2020-05-04T06:45:39.692160Z |
| Orbit solution date (soln_date, UTC) |
2025-01-02T20:13:03Z |
| Obs used |
136 |
| NEO |
- |
| M1 |
6.800 |
| K1 |
36.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2016-07-03T13:38:06.950400Z |
| Discovery magnitude (MPC) |
23.20 T |
| Discovery observatory (MPC) |
T09 · Subaru Telescope, Maunakea |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-04-13.0000000 |
| e |
0.11977371 |
| q (au) |
2.329381 |
| a (au) |
2.646344 |
| i (deg) |
5.222268 |
| Ω (om, deg) |
176.012536 |
| ω (w, deg) |
104.953942 |
| M (ma, deg) |
355.127619 |
Magnitude
Scatter + Global Linear
$$
M_a = (20.000 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
20.000 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.721 |
| k |
0.978 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
06:25:09.51 |
+19:14:29.5 |
HIP 30496 |
28.73 |
| 2026-07-29 12:00 |
06:25:55.43 |
+19:13:47.3 |
HIP 30734 |
25.05 |
| 2026-07-30 00:00 |
06:26:41.28 |
+19:13:04.1 |
HIP 30734 |
17.66 |
| 2026-07-30 12:00 |
06:27:27.08 |
+19:12:20.0 |
HIP 30734 |
15.22 |
| 2026-07-31 00:00 |
06:28:12.82 |
+19:11:34.9 |
HIP 30734 |
19.65 |
| 2026-07-31 12:00 |
06:28:58.49 |
+19:10:48.9 |
HIP 31014 |
22.24 |
| 2026-08-01 00:00 |
06:29:44.11 |
+19:10:02.0 |
HIP 31014 |
12.73 |
| 2026-08-01 12:00 |
06:30:29.66 |
+19:09:14.2 |
HIP 31014 |
7.90 |
| 2026-08-02 00:00 |
06:31:15.16 |
+19:08:25.5 |
HIP 31014 |
13.98 |
| 2026-08-02 12:00 |
06:32:00.58 |
+19:07:35.9 |
HIP 31014 |
23.66 |
| 2026-08-03 00:00 |
06:32:45.95 |
+19:06:45.3 |
HIP 31261 |
21.20 |
| 2026-08-03 12:00 |
06:33:31.25 |
+19:05:53.9 |
HIP 31261 |
18.52 |
| 2026-08-04 00:00 |
06:34:16.49 |
+19:05:01.5 |
HIP 31368 |
21.41 |
| 2026-08-04 12:00 |
06:35:01.66 |
+19:04:08.2 |
HIP 31368 |
22.24 |
| 2026-08-05 00:00 |
06:35:46.76 |
+19:03:14.1 |
HIP 31618 |
18.89 |
| 2026-08-05 12:00 |
06:36:31.80 |
+19:02:19.0 |
HIP 31618 |
10.21 |
| 2026-08-06 00:00 |
06:37:16.77 |
+19:01:23.1 |
HIP 31618 |
8.94 |
| 2026-08-06 12:00 |
06:38:01.67 |
+19:00:26.3 |
HIP 31618 |
16.82 |
| 2026-08-07 00:00 |
06:38:46.51 |
+18:59:28.6 |
HIP 31618 |
26.69 |
| 2026-08-07 12:00 |
06:39:31.27 |
+18:58:30.0 |
HIP 32023 |
26.51 |
| 2026-08-08 00:00 |
06:40:15.96 |
+18:57:30.6 |
HIP 32023 |
15.90 |
| 2026-08-08 12:00 |
06:41:00.58 |
+18:56:30.2 |
HIP 32023 |
5.30 |
| 2026-08-09 00:00 |
06:41:45.12 |
+18:55:29.1 |
HIP 32023 |
5.28 |
| 2026-08-09 12:00 |
06:42:29.59 |
+18:54:27.0 |
HIP 32023 |
15.85 |
| 2026-08-10 00:00 |
06:43:13.99 |
+18:53:24.1 |
HIP 32238 |
16.10 |
| 2026-08-10 12:00 |
06:43:58.31 |
+18:52:20.4 |
HIP 32238 |
13.25 |
| 2026-08-11 00:00 |
06:44:42.55 |
+18:51:15.8 |
HIP 32238 |
17.70 |
| 2026-08-11 12:00 |
06:45:26.72 |
+18:50:10.4 |
HIP 32451 |
12.87 |
| 2026-08-12 00:00 |
06:46:10.81 |
+18:49:04.1 |
HIP 32451 |
2.71 |
| 2026-08-12 12:00 |
06:46:54.81 |
+18:47:57.0 |
HIP 32451 |
8.31 |
| 2026-08-13 00:00 |
06:47:38.74 |
+18:46:49.1 |
HIP 32554 |
9.78 |
| 2026-08-13 12:00 |
06:48:22.58 |
+18:45:40.3 |
HIP 32554 |
15.90 |
| 2026-08-14 00:00 |
06:49:06.35 |
+18:44:30.8 |
HIP 32797 |
16.37 |
| 2026-08-14 12:00 |
06:49:50.02 |
+18:43:20.4 |
HIP 32797 |
7.27 |
| 2026-08-15 00:00 |
06:50:33.62 |
+18:42:09.3 |
HIP 32797 |
7.37 |
| 2026-08-15 12:00 |
06:51:17.13 |
+18:40:57.3 |
HIP 32797 |
16.47 |
| 2026-08-16 00:00 |
06:52:00.55 |
+18:39:44.5 |
HIP 32983 |
22.53 |
| 2026-08-16 12:00 |
06:52:43.89 |
+18:38:31.0 |
HIP 32983 |
21.98 |
| 2026-08-17 00:00 |
06:53:27.14 |
+18:37:16.7 |
HIP 33067 |
20.49 |
| 2026-08-17 12:00 |
06:54:10.30 |
+18:36:01.6 |
HIP 33067 |
23.25 |
| 2026-08-18 00:00 |
06:54:53.37 |
+18:34:45.7 |
HIP 33326 |
15.18 |
| 2026-08-18 12:00 |
06:55:36.35 |
+18:33:29.1 |
HIP 33326 |
5.68 |
| 2026-08-19 00:00 |
06:56:19.24 |
+18:32:11.7 |
HIP 33326 |
6.68 |