| Parameter |
Value |
| Designation |
349P/Lemmon |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2017-08-26T12:49:38.985600Z |
| Orbit solution date (soln_date, UTC) |
2024-06-14T15:42:23Z |
| Obs used |
209 |
| NEO |
- |
| M1 |
10.800 |
| K1 |
17.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-08-10.0000000 |
| e |
0.29990139 |
| q (au) |
2.499745 |
| a (au) |
3.570561 |
| i (deg) |
5.492271 |
| Ω (om, deg) |
331.761163 |
| ω (w, deg) |
255.998978 |
| M (ma, deg) |
104.225129 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.373 + 3.703\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.373 |
| n |
3.703 |
| gf |
0.996 |
| gb |
-0.646 |
| k |
0.914 |
| δ90 |
9.995 |
| 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) |
| 2026-03-26 00:00 |
23:47:40.95 |
+00:36:22.3 |
HIP 117260 |
17.19 |
| 2026-03-26 12:00 |
23:48:11.93 |
+00:40:00.4 |
HIP 117457 |
17.90 |
| 2026-03-27 00:00 |
23:48:42.87 |
+00:43:38.5 |
HIP 117457 |
17.76 |
| 2026-03-27 12:00 |
23:49:13.79 |
+00:47:16.4 |
HIP 117491 |
17.63 |
| 2026-03-28 00:00 |
23:49:44.67 |
+00:50:54.2 |
HIP 117491 |
14.33 |
| 2026-03-28 12:00 |
23:50:15.52 |
+00:54:31.9 |
HIP 117491 |
15.65 |
| 2026-03-29 00:00 |
23:50:46.34 |
+00:58:09.4 |
HIP 117491 |
20.73 |
| 2026-03-29 12:00 |
23:51:17.12 |
+01:01:46.8 |
HIP 117491 |
27.55 |
| 2026-03-30 00:00 |
23:51:47.87 |
+01:05:24.1 |
HIP 117704 |
25.56 |
| 2026-03-30 12:00 |
23:52:18.59 |
+01:09:01.2 |
HIP 117704 |
20.90 |
| 2026-03-31 00:00 |
23:52:49.28 |
+01:12:38.2 |
HIP 117704 |
19.09 |
| 2026-03-31 12:00 |
23:53:19.93 |
+01:16:15.0 |
HIP 117704 |
20.87 |
| 2026-04-01 00:00 |
23:53:50.54 |
+01:19:51.7 |
HIP 117805 |
22.77 |
| 2026-04-01 12:00 |
23:54:21.12 |
+01:23:28.2 |
HIP 117805 |
22.29 |
| 2026-04-02 00:00 |
23:54:51.67 |
+01:27:04.6 |
HIP 117805 |
24.85 |
| 2026-04-02 12:00 |
23:55:22.18 |
+01:30:40.8 |
HIP 118035 |
23.57 |
| 2026-04-03 00:00 |
23:55:52.65 |
+01:34:16.8 |
HIP 118035 |
21.68 |
| 2026-04-03 12:00 |
23:56:23.09 |
+01:37:52.7 |
HIP 118030 |
17.34 |
| 2026-04-04 00:00 |
23:56:53.49 |
+01:41:28.3 |
HIP 118030 |
14.79 |
| 2026-04-04 12:00 |
23:57:23.85 |
+01:45:03.9 |
HIP 118030 |
16.67 |
| 2026-04-05 00:00 |
23:57:54.18 |
+01:48:39.2 |
HIP 118030 |
21.85 |
| 2026-04-05 12:00 |
23:58:24.46 |
+01:52:14.4 |
HIP 118030 |
28.58 |
| 2026-04-06 00:00 |
23:58:54.71 |
+01:55:49.3 |
HIP 118030 |
36.00 |
| 2026-04-06 12:00 |
23:59:24.92 |
+01:59:24.1 |
HIP 31 |
43.66 |
| 2026-04-07 00:00 |
23:59:55.09 |
+02:02:58.7 |
HIP 31 |
38.22 |
| 2026-04-07 12:00 |
00:00:25.23 |
+02:06:33.1 |
HIP 31 |
33.98 |
| 2026-04-08 00:00 |
00:00:55.32 |
+02:10:07.3 |
HIP 223 |
28.03 |
| 2026-04-08 12:00 |
00:01:25.37 |
+02:13:41.3 |
HIP 223 |
21.25 |
| 2026-04-09 00:00 |
00:01:55.38 |
+02:17:15.1 |
HIP 223 |
16.00 |
| 2026-04-09 12:00 |
00:02:25.34 |
+02:20:48.7 |
HIP 223 |
14.08 |
| 2026-04-10 00:00 |
00:02:55.27 |
+02:24:22.0 |
HIP 223 |
16.67 |
| 2026-04-10 12:00 |
00:03:25.15 |
+02:27:55.1 |
HIP 223 |
22.23 |
| 2026-04-11 00:00 |
00:03:54.99 |
+02:31:28.0 |
HIP 429 |
20.27 |
| 2026-04-11 12:00 |
00:04:24.78 |
+02:35:00.7 |
HIP 429 |
15.91 |
| 2026-04-12 00:00 |
00:04:54.54 |
+02:38:33.2 |
HIP 429 |
15.22 |
| 2026-04-12 12:00 |
00:05:24.24 |
+02:42:05.4 |
HIP 489 |
7.87 |
| 2026-04-13 00:00 |
00:05:53.90 |
+02:45:37.3 |
HIP 489 |
0.57 |
| 2026-04-13 12:00 |
00:06:23.52 |
+02:49:09.1 |
HIP 489 |
8.55 |
| 2026-04-14 00:00 |
00:06:53.09 |
+02:52:40.5 |
HIP 489 |
16.73 |
| 2026-04-14 12:00 |
00:07:22.61 |
+02:56:11.7 |
HIP 489 |
24.90 |
| 2026-04-15 00:00 |
00:07:52.08 |
+02:59:42.7 |
HIP 675 |
27.76 |
| 2026-04-15 12:00 |
00:08:21.51 |
+03:03:13.4 |
HIP 675 |
23.22 |
| 2026-04-16 00:00 |
00:08:50.89 |
+03:06:43.8 |
HIP 675 |
20.98 |