| Parameter |
Value |
| Designation |
302P/Lemmon-PANSTARRS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2025-03-08T21:15:53.916480Z |
| Orbit solution date (soln_date, UTC) |
2026-03-12T00:52:29Z |
| Obs used |
985 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
16.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-08-11.0000000 |
| e |
0.23012574 |
| q (au) |
3.288855 |
| a (au) |
4.271937 |
| i (deg) |
6.033718 |
| Ω (om, deg) |
121.724714 |
| ω (w, deg) |
208.540458 |
| M (ma, deg) |
295.715939 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.485 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.485 |
| n |
6.000 |
| gf |
0.906 |
| gb |
-0.910 |
| k |
1.000 |
| δ90 |
3.370 |
| 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 |
+19.3492 |
-9.991 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
01:53:31.52 |
+06:27:50.0 |
HIP 8951 |
26.59 |
| 2026-03-26 12:00 |
01:54:07.00 |
+06:31:21.2 |
HIP 8951 |
18.45 |
| 2026-03-27 00:00 |
01:54:42.53 |
+06:34:52.0 |
HIP 8951 |
12.40 |
| 2026-03-27 12:00 |
01:55:18.08 |
+06:38:22.5 |
HIP 8951 |
12.14 |
| 2026-03-28 00:00 |
01:55:53.67 |
+06:41:52.8 |
HIP 8951 |
17.93 |
| 2026-03-28 12:00 |
01:56:29.30 |
+06:45:22.6 |
HIP 9079 |
25.11 |
| 2026-03-29 00:00 |
01:57:04.95 |
+06:48:52.2 |
HIP 9079 |
27.97 |
| 2026-03-29 12:00 |
01:57:40.64 |
+06:52:21.4 |
HIP 9253 |
22.27 |
| 2026-03-30 00:00 |
01:58:16.36 |
+06:55:50.4 |
HIP 9253 |
18.33 |
| 2026-03-30 12:00 |
01:58:52.10 |
+06:59:18.9 |
HIP 9253 |
18.90 |
| 2026-03-31 00:00 |
01:59:27.88 |
+07:02:47.2 |
HIP 9355 |
13.53 |
| 2026-03-31 12:00 |
02:00:03.69 |
+07:06:15.0 |
HIP 9355 |
11.39 |
| 2026-04-01 00:00 |
02:00:39.53 |
+07:09:42.6 |
HIP 9355 |
16.07 |
| 2026-04-01 12:00 |
02:01:15.40 |
+07:13:09.8 |
HIP 9355 |
23.85 |
| 2026-04-02 00:00 |
02:01:51.30 |
+07:16:36.6 |
HIP 9355 |
32.58 |
| 2026-04-02 12:00 |
02:02:27.22 |
+07:20:03.1 |
HIP 9548 |
27.70 |
| 2026-04-03 00:00 |
02:03:03.18 |
+07:23:29.2 |
HIP 9548 |
24.55 |
| 2026-04-03 12:00 |
02:03:39.16 |
+07:26:54.9 |
HIP 9706 |
24.77 |
| 2026-04-04 00:00 |
02:04:15.17 |
+07:30:20.3 |
HIP 9706 |
16.41 |
| 2026-04-04 12:00 |
02:04:51.20 |
+07:33:45.3 |
HIP 9706 |
10.38 |
| 2026-04-05 00:00 |
02:05:27.26 |
+07:37:09.9 |
HIP 9706 |
11.38 |
| 2026-04-05 12:00 |
02:06:03.35 |
+07:40:34.2 |
HIP 9706 |
18.28 |
| 2026-04-06 00:00 |
02:06:39.46 |
+07:43:58.0 |
HIP 9920 |
20.62 |
| 2026-04-06 12:00 |
02:07:15.60 |
+07:47:21.5 |
HIP 9920 |
12.12 |
| 2026-04-07 00:00 |
02:07:51.77 |
+07:50:44.6 |
HIP 9920 |
7.19 |
| 2026-04-07 12:00 |
02:08:27.95 |
+07:54:07.2 |
HIP 9920 |
11.83 |
| 2026-04-08 00:00 |
02:09:04.17 |
+07:57:29.5 |
HIP 10107 |
17.88 |
| 2026-04-08 12:00 |
02:09:40.40 |
+08:00:51.4 |
HIP 10107 |
14.78 |
| 2026-04-09 00:00 |
02:10:16.66 |
+08:04:12.8 |
HIP 10107 |
17.35 |
| 2026-04-09 12:00 |
02:10:52.94 |
+08:07:33.9 |
HIP 10171 |
14.59 |
| 2026-04-10 00:00 |
02:11:29.25 |
+08:10:54.5 |
HIP 10171 |
14.94 |
| 2026-04-10 12:00 |
02:12:05.57 |
+08:14:14.7 |
HIP 10171 |
20.44 |
| 2026-04-11 00:00 |
02:12:41.92 |
+08:17:34.4 |
HIP 10212 |
25.99 |
| 2026-04-11 12:00 |
02:13:18.29 |
+08:20:53.8 |
HIP 10411 |
22.72 |
| 2026-04-12 00:00 |
02:13:54.67 |
+08:24:12.7 |
HIP 10411 |
22.37 |
| 2026-04-12 12:00 |
02:14:31.08 |
+08:27:31.1 |
HIP 10411 |
25.85 |
| 2026-04-13 00:00 |
02:15:07.51 |
+08:30:49.2 |
HIP 10411 |
31.94 |
| 2026-04-13 12:00 |
02:15:43.96 |
+08:34:06.7 |
HIP 10411 |
39.44 |
| 2026-04-14 00:00 |
02:16:20.42 |
+08:37:23.8 |
HIP 10737 |
35.93 |
| 2026-04-14 12:00 |
02:16:56.91 |
+08:40:40.5 |
HIP 10737 |
27.11 |
| 2026-04-15 00:00 |
02:17:33.41 |
+08:43:56.7 |
HIP 10737 |
19.07 |
| 2026-04-15 12:00 |
02:18:09.93 |
+08:47:12.4 |
HIP 10737 |
13.27 |
| 2026-04-16 00:00 |
02:18:46.46 |
+08:50:27.7 |
HIP 10737 |
13.15 |