| Parameter |
Value |
| Designation |
C/2007 K1 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2007-05-07T15:34:22.368000Z |
| Orbit solution date (soln_date, UTC) |
2022-06-20T23:12:31Z |
| Obs used |
141 |
| NEO |
- |
| M1 |
11.000 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2007-06-26.0000000 |
| e |
0.97872535 |
| q (au) |
9.239049 |
| a (au) |
434.274942 |
| i (deg) |
108.433102 |
| Ω (om, deg) |
294.661115 |
| ω (w, deg) |
51.970917 |
| M (ma, deg) |
0.005375 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.857 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.857 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
08:03:41.57 |
+30:59:25.7 |
HIP 39459 |
25.23 |
| 2026-05-12 12:00 |
08:03:42.80 |
+30:59:06.8 |
HIP 39459 |
24.89 |
| 2026-05-13 00:00 |
08:03:44.06 |
+30:58:47.7 |
HIP 39459 |
24.55 |
| 2026-05-13 12:00 |
08:03:45.36 |
+30:58:28.7 |
HIP 39459 |
24.20 |
| 2026-05-14 00:00 |
08:03:46.68 |
+30:58:09.6 |
HIP 39459 |
23.86 |
| 2026-05-14 12:00 |
08:03:48.04 |
+30:57:50.4 |
HIP 39459 |
23.52 |
| 2026-05-15 00:00 |
08:03:49.42 |
+30:57:31.2 |
HIP 39459 |
23.18 |
| 2026-05-15 12:00 |
08:03:50.84 |
+30:57:12.0 |
HIP 39459 |
22.85 |
| 2026-05-16 00:00 |
08:03:52.28 |
+30:56:52.8 |
HIP 39459 |
22.51 |
| 2026-05-16 12:00 |
08:03:53.76 |
+30:56:33.5 |
HIP 39459 |
22.18 |
| 2026-05-17 00:00 |
08:03:55.26 |
+30:56:14.1 |
HIP 39459 |
21.86 |
| 2026-05-17 12:00 |
08:03:56.80 |
+30:55:54.8 |
HIP 39459 |
21.54 |
| 2026-05-18 00:00 |
08:03:58.36 |
+30:55:35.4 |
HIP 39459 |
21.22 |
| 2026-05-18 12:00 |
08:03:59.96 |
+30:55:16.0 |
HIP 39459 |
20.91 |
| 2026-05-19 00:00 |
08:04:01.58 |
+30:54:56.5 |
HIP 39459 |
20.60 |
| 2026-05-19 12:00 |
08:04:03.23 |
+30:54:37.0 |
HIP 39459 |
20.30 |
| 2026-05-20 00:00 |
08:04:04.91 |
+30:54:17.5 |
HIP 39459 |
20.01 |
| 2026-05-20 12:00 |
08:04:06.62 |
+30:53:57.9 |
HIP 39459 |
19.73 |
| 2026-05-21 00:00 |
08:04:08.36 |
+30:53:38.4 |
HIP 39459 |
19.45 |
| 2026-05-21 12:00 |
08:04:10.12 |
+30:53:18.8 |
HIP 39459 |
19.19 |
| 2026-05-22 00:00 |
08:04:11.92 |
+30:52:59.1 |
HIP 39459 |
18.93 |
| 2026-05-22 12:00 |
08:04:13.74 |
+30:52:39.5 |
HIP 39459 |
18.69 |
| 2026-05-23 00:00 |
08:04:15.59 |
+30:52:19.8 |
HIP 39459 |
18.45 |
| 2026-05-23 12:00 |
08:04:17.46 |
+30:52:00.1 |
HIP 39459 |
18.23 |
| 2026-05-24 00:00 |
08:04:19.36 |
+30:51:40.4 |
HIP 39459 |
18.03 |
| 2026-05-24 12:00 |
08:04:21.29 |
+30:51:20.7 |
HIP 39459 |
17.84 |
| 2026-05-25 00:00 |
08:04:23.25 |
+30:51:00.9 |
HIP 39459 |
17.66 |
| 2026-05-25 12:00 |
08:04:25.23 |
+30:50:41.1 |
HIP 39459 |
17.50 |
| 2026-05-26 00:00 |
08:04:27.24 |
+30:50:21.3 |
HIP 39459 |
17.36 |
| 2026-05-26 12:00 |
08:04:29.27 |
+30:50:01.5 |
HIP 39459 |
17.23 |
| 2026-05-27 00:00 |
08:04:31.33 |
+30:49:41.7 |
HIP 39459 |
17.13 |
| 2026-05-27 12:00 |
08:04:33.42 |
+30:49:21.8 |
HIP 39459 |
17.04 |
| 2026-05-28 00:00 |
08:04:35.53 |
+30:49:01.9 |
HIP 39459 |
16.97 |
| 2026-05-28 12:00 |
08:04:37.67 |
+30:48:42.1 |
HIP 39459 |
16.93 |
| 2026-05-29 00:00 |
08:04:39.83 |
+30:48:22.2 |
HIP 39459 |
16.91 |
| 2026-05-29 12:00 |
08:04:42.02 |
+30:48:02.3 |
HIP 39459 |
16.91 |
| 2026-05-30 00:00 |
08:04:44.23 |
+30:47:42.4 |
HIP 39459 |
16.93 |
| 2026-05-30 12:00 |
08:04:46.47 |
+30:47:22.4 |
HIP 39459 |
16.97 |
| 2026-05-31 00:00 |
08:04:48.73 |
+30:47:02.5 |
HIP 39459 |
17.04 |
| 2026-05-31 12:00 |
08:04:51.01 |
+30:46:42.5 |
HIP 39459 |
17.13 |
| 2026-06-01 00:00 |
08:04:53.32 |
+30:46:22.6 |
HIP 39459 |
17.25 |
| 2026-06-01 12:00 |
08:04:55.66 |
+30:46:02.6 |
HIP 39459 |
17.39 |
| 2026-06-02 00:00 |
08:04:58.01 |
+30:45:42.7 |
HIP 39459 |
17.55 |