| Parameter |
Value |
| Designation |
C/2017 E5 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-06-10T21:21:43.948800Z |
| Orbit solution date (soln_date, UTC) |
2022-06-20T23:12:32Z |
| Obs used |
112 |
| NEO |
- |
| M1 |
15.900 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-01-12.0000000 |
| e |
0.99563963 |
| q (au) |
1.783311 |
| a (au) |
408.982042 |
| i (deg) |
122.637072 |
| Ω (om, deg) |
206.191666 |
| ω (w, deg) |
306.771175 |
| M (ma, deg) |
0.025634 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.408 + 3.382\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.408 |
| n |
3.382 |
| gf |
0.980 |
| gb |
-0.863 |
| k |
0.800 |
| 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) |
| 2026-06-01 00:00 |
08:22:41.11 |
+77:01:23.7 |
HIP 41239 |
8.22 |
| 2026-06-01 12:00 |
08:22:51.86 |
+77:00:32.0 |
HIP 41239 |
7.32 |
| 2026-06-02 00:00 |
08:23:02.72 |
+76:59:40.5 |
HIP 41239 |
6.47 |
| 2026-06-02 12:00 |
08:23:13.69 |
+76:58:49.2 |
HIP 41239 |
5.68 |
| 2026-06-03 00:00 |
08:23:24.76 |
+76:57:58.2 |
HIP 41239 |
4.99 |
| 2026-06-03 12:00 |
08:23:35.95 |
+76:57:07.4 |
HIP 41239 |
4.43 |
| 2026-06-04 00:00 |
08:23:47.23 |
+76:56:16.8 |
HIP 41239 |
4.06 |
| 2026-06-04 12:00 |
08:23:58.62 |
+76:55:26.5 |
HIP 41239 |
3.94 |
| 2026-06-05 00:00 |
08:24:10.12 |
+76:54:36.5 |
HIP 41239 |
4.09 |
| 2026-06-05 12:00 |
08:24:21.72 |
+76:53:46.7 |
HIP 41239 |
4.48 |
| 2026-06-06 00:00 |
08:24:33.42 |
+76:52:57.2 |
HIP 41239 |
5.06 |
| 2026-06-06 12:00 |
08:24:45.22 |
+76:52:08.0 |
HIP 41239 |
5.78 |
| 2026-06-07 00:00 |
08:24:57.12 |
+76:51:19.0 |
HIP 41239 |
6.58 |
| 2026-06-07 12:00 |
08:25:09.11 |
+76:50:30.2 |
HIP 41239 |
7.44 |
| 2026-06-08 00:00 |
08:25:21.21 |
+76:49:41.8 |
HIP 41239 |
8.35 |
| 2026-06-08 12:00 |
08:25:33.40 |
+76:48:53.6 |
HIP 41239 |
9.28 |
| 2026-06-09 00:00 |
08:25:45.69 |
+76:48:05.6 |
HIP 41239 |
10.24 |
| 2026-06-09 12:00 |
08:25:58.07 |
+76:47:18.0 |
HIP 41239 |
11.21 |
| 2026-06-10 00:00 |
08:26:10.55 |
+76:46:30.6 |
HIP 41239 |
12.20 |
| 2026-06-10 12:00 |
08:26:23.12 |
+76:45:43.5 |
HIP 41239 |
13.19 |
| 2026-06-11 00:00 |
08:26:35.78 |
+76:44:56.6 |
HIP 41239 |
14.20 |
| 2026-06-11 12:00 |
08:26:48.53 |
+76:44:10.1 |
HIP 41239 |
15.21 |
| 2026-06-12 00:00 |
08:27:01.37 |
+76:43:23.8 |
HIP 41239 |
16.22 |
| 2026-06-12 12:00 |
08:27:14.30 |
+76:42:37.9 |
HIP 41239 |
17.24 |
| 2026-06-13 00:00 |
08:27:27.32 |
+76:41:52.2 |
HIP 41239 |
18.27 |
| 2026-06-13 12:00 |
08:27:40.42 |
+76:41:06.8 |
HIP 41239 |
19.29 |
| 2026-06-14 00:00 |
08:27:53.61 |
+76:40:21.7 |
HIP 41239 |
20.32 |
| 2026-06-14 12:00 |
08:28:06.88 |
+76:39:36.9 |
HIP 41608 |
21.34 |
| 2026-06-15 00:00 |
08:28:20.24 |
+76:38:52.4 |
HIP 41608 |
20.51 |
| 2026-06-15 12:00 |
08:28:33.67 |
+76:38:08.2 |
HIP 41608 |
19.71 |
| 2026-06-16 00:00 |
08:28:47.19 |
+76:37:24.2 |
HIP 41608 |
18.94 |
| 2026-06-16 12:00 |
08:29:00.79 |
+76:36:40.7 |
HIP 41608 |
18.21 |
| 2026-06-17 00:00 |
08:29:14.47 |
+76:35:57.4 |
HIP 41608 |
17.52 |
| 2026-06-17 12:00 |
08:29:28.22 |
+76:35:14.4 |
HIP 41608 |
16.88 |
| 2026-06-18 00:00 |
08:29:42.06 |
+76:34:31.7 |
HIP 41608 |
16.28 |
| 2026-06-18 12:00 |
08:29:55.96 |
+76:33:49.4 |
HIP 41608 |
15.75 |
| 2026-06-19 00:00 |
08:30:09.94 |
+76:33:07.3 |
HIP 41608 |
15.28 |
| 2026-06-19 12:00 |
08:30:24.00 |
+76:32:25.6 |
HIP 41608 |
14.88 |
| 2026-06-20 00:00 |
08:30:38.12 |
+76:31:44.2 |
HIP 41608 |
14.56 |
| 2026-06-20 12:00 |
08:30:52.32 |
+76:31:03.1 |
HIP 41608 |
14.31 |
| 2026-06-21 00:00 |
08:31:06.59 |
+76:30:22.3 |
HIP 41608 |
14.16 |
| 2026-06-21 12:00 |
08:31:20.92 |
+76:29:41.9 |
HIP 41608 |
14.09 |
| 2026-06-22 00:00 |
08:31:35.33 |
+76:29:01.8 |
HIP 41608 |
14.11 |