302P/Lemmon-PANSTARRS
| Parameter |
Value |
| Designation |
302P/Lemmon-PANSTARRS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2025-03-08T20:10:38.208000Z |
| Orbit solution date (soln_date, UTC) |
2026-01-13T08:12:54Z |
| Obs used |
964 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
16.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-07-22.0000000 |
| e |
0.23014027 |
| q (au) |
3.288915 |
| a (au) |
4.272097 |
| i (deg) |
6.033673 |
| Ω (om, deg) |
121.725541 |
| ω (w, deg) |
208.532055 |
| M (ma, deg) |
293.492190 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.350 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.350 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.904 |
| k |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2023-03-27 |
2024-12-03 |
+19.6054 |
-10.175 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
00:58:06.24 |
+00:19:43.5 |
HIP 4464 |
13.33 |
| 2026-02-03 12:00 |
00:58:34.83 |
+00:23:14.4 |
HIP 4464 |
20.62 |
| 2026-02-04 00:00 |
00:59:03.52 |
+00:26:45.7 |
HIP 4642 |
15.82 |
| 2026-02-04 12:00 |
00:59:32.32 |
+00:30:17.3 |
HIP 4642 |
10.02 |
| 2026-02-05 00:00 |
01:00:01.22 |
+00:33:49.2 |
HIP 4642 |
8.90 |
| 2026-02-05 12:00 |
01:00:30.23 |
+00:37:21.4 |
HIP 4642 |
13.71 |
| 2026-02-06 00:00 |
01:00:59.33 |
+00:40:54.0 |
HIP 4642 |
20.69 |
| 2026-02-06 12:00 |
01:01:28.54 |
+00:44:26.9 |
HIP 4642 |
28.29 |
| 2026-02-07 00:00 |
01:01:57.85 |
+00:48:00.0 |
HIP 4642 |
36.15 |
| 2026-02-07 12:00 |
01:02:27.25 |
+00:51:33.5 |
HIP 5017 |
31.22 |
| 2026-02-08 00:00 |
01:02:56.76 |
+00:55:07.3 |
HIP 5017 |
27.19 |
| 2026-02-08 12:00 |
01:03:26.36 |
+00:58:41.3 |
HIP 4979 |
24.00 |
| 2026-02-09 00:00 |
01:03:56.06 |
+01:02:15.6 |
HIP 4979 |
19.84 |
| 2026-02-09 12:00 |
01:04:25.86 |
+01:05:50.2 |
HIP 4979 |
18.63 |
| 2026-02-10 00:00 |
01:04:55.76 |
+01:09:25.0 |
HIP 5123 |
10.95 |
| 2026-02-10 12:00 |
01:05:25.74 |
+01:13:00.1 |
HIP 5123 |
3.27 |
| 2026-02-11 00:00 |
01:05:55.83 |
+01:16:35.4 |
HIP 5123 |
6.31 |
| 2026-02-11 12:00 |
01:06:26.00 |
+01:20:11.0 |
HIP 5257 |
11.76 |
| 2026-02-12 00:00 |
01:06:56.27 |
+01:23:46.8 |
HIP 5257 |
4.82 |
| 2026-02-12 12:00 |
01:07:26.63 |
+01:27:22.8 |
HIP 5257 |
6.98 |
| 2026-02-13 00:00 |
01:07:57.09 |
+01:30:59.1 |
HIP 5257 |
14.69 |
| 2026-02-13 12:00 |
01:08:27.63 |
+01:34:35.5 |
HIP 5257 |
22.93 |
| 2026-02-14 00:00 |
01:08:58.26 |
+01:38:12.2 |
HIP 5315 |
25.98 |
| 2026-02-14 12:00 |
01:09:28.98 |
+01:41:49.0 |
HIP 5448 |
28.58 |
| 2026-02-15 00:00 |
01:09:59.79 |
+01:45:26.1 |
HIP 5448 |
32.13 |
| 2026-02-15 12:00 |
01:10:30.69 |
+01:49:03.3 |
HIP 5448 |
37.33 |
| 2026-02-16 00:00 |
01:11:01.67 |
+01:52:40.7 |
HIP 5510 |
34.78 |
| 2026-02-16 12:00 |
01:11:32.73 |
+01:56:18.3 |
HIP 5510 |
33.84 |
| 2026-02-17 00:00 |
01:12:03.89 |
+01:59:56.0 |
HIP 5646 |
29.16 |
| 2026-02-17 12:00 |
01:12:35.12 |
+02:03:33.8 |
HIP 5646 |
24.77 |
| 2026-02-18 00:00 |
01:13:06.44 |
+02:07:11.9 |
HIP 5646 |
22.92 |
| 2026-02-18 12:00 |
01:13:37.84 |
+02:10:50.0 |
HIP 5818 |
17.15 |
| 2026-02-19 00:00 |
01:14:09.32 |
+02:14:28.3 |
HIP 5818 |
8.49 |
| 2026-02-19 12:00 |
01:14:40.89 |
+02:18:06.6 |
HIP 5818 |
0.21 |
| 2026-02-20 00:00 |
01:15:12.53 |
+02:21:45.1 |
HIP 5818 |
8.90 |
| 2026-02-20 12:00 |
01:15:44.25 |
+02:25:23.7 |
HIP 5818 |
17.62 |
| 2026-02-21 00:00 |
01:16:16.05 |
+02:29:02.4 |
HIP 5949 |
15.85 |
| 2026-02-21 12:00 |
01:16:47.92 |
+02:32:41.2 |
HIP 5949 |
11.79 |
| 2026-02-22 00:00 |
01:17:19.87 |
+02:36:20.1 |
HIP 5949 |
13.44 |
| 2026-02-22 12:00 |
01:17:51.90 |
+02:39:59.0 |
HIP 6096 |
9.10 |
| 2026-02-23 00:00 |
01:18:24.00 |
+02:43:38.0 |
HIP 6096 |
10.81 |
| 2026-02-23 12:00 |
01:18:56.17 |
+02:47:17.1 |
HIP 6096 |
17.50 |
| 2026-02-24 00:00 |
01:19:28.42 |
+02:50:56.2 |
HIP 6263 |
25.19 |