| 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) |
| 2026-03-26 00:00 |
08:04:17.02 |
+31:23:59.8 |
HIP 39605 |
17.63 |
| 2026-03-26 12:00 |
08:04:15.01 |
+31:23:48.5 |
HIP 39605 |
17.99 |
| 2026-03-27 00:00 |
08:04:13.03 |
+31:23:37.2 |
HIP 39605 |
18.35 |
| 2026-03-27 12:00 |
08:04:11.09 |
+31:23:25.7 |
HIP 39605 |
18.71 |
| 2026-03-28 00:00 |
08:04:09.18 |
+31:23:14.1 |
HIP 39605 |
19.06 |
| 2026-03-28 12:00 |
08:04:07.30 |
+31:23:02.4 |
HIP 39605 |
19.41 |
| 2026-03-29 00:00 |
08:04:05.46 |
+31:22:50.5 |
HIP 39605 |
19.75 |
| 2026-03-29 12:00 |
08:04:03.66 |
+31:22:38.6 |
HIP 39605 |
20.09 |
| 2026-03-30 00:00 |
08:04:01.89 |
+31:22:26.5 |
HIP 39605 |
20.43 |
| 2026-03-30 12:00 |
08:04:00.16 |
+31:22:14.3 |
HIP 39605 |
20.76 |
| 2026-03-31 00:00 |
08:03:58.46 |
+31:22:02.1 |
HIP 39605 |
21.09 |
| 2026-03-31 12:00 |
08:03:56.79 |
+31:21:49.7 |
HIP 39605 |
21.41 |
| 2026-04-01 00:00 |
08:03:55.16 |
+31:21:37.1 |
HIP 39605 |
21.73 |
| 2026-04-01 12:00 |
08:03:53.57 |
+31:21:24.5 |
HIP 39605 |
22.04 |
| 2026-04-02 00:00 |
08:03:52.01 |
+31:21:11.8 |
HIP 39605 |
22.35 |
| 2026-04-02 12:00 |
08:03:50.49 |
+31:20:58.9 |
HIP 39605 |
22.66 |
| 2026-04-03 00:00 |
08:03:49.00 |
+31:20:46.0 |
HIP 39605 |
22.96 |
| 2026-04-03 12:00 |
08:03:47.55 |
+31:20:32.9 |
HIP 39605 |
23.25 |
| 2026-04-04 00:00 |
08:03:46.13 |
+31:20:19.8 |
HIP 39605 |
23.54 |
| 2026-04-04 12:00 |
08:03:44.75 |
+31:20:06.5 |
HIP 39605 |
23.82 |
| 2026-04-05 00:00 |
08:03:43.40 |
+31:19:53.1 |
HIP 39605 |
24.10 |
| 2026-04-05 12:00 |
08:03:42.09 |
+31:19:39.6 |
HIP 39605 |
24.37 |
| 2026-04-06 00:00 |
08:03:40.82 |
+31:19:26.1 |
HIP 39605 |
24.64 |
| 2026-04-06 12:00 |
08:03:39.58 |
+31:19:12.4 |
HIP 39605 |
24.90 |
| 2026-04-07 00:00 |
08:03:38.37 |
+31:18:58.6 |
HIP 39605 |
25.16 |
| 2026-04-07 12:00 |
08:03:37.20 |
+31:18:44.7 |
HIP 39605 |
25.41 |
| 2026-04-08 00:00 |
08:03:36.07 |
+31:18:30.7 |
HIP 39605 |
25.65 |
| 2026-04-08 12:00 |
08:03:34.98 |
+31:18:16.6 |
HIP 39259 |
25.36 |
| 2026-04-09 00:00 |
08:03:33.92 |
+31:18:02.4 |
HIP 39259 |
25.07 |
| 2026-04-09 12:00 |
08:03:32.89 |
+31:17:48.1 |
HIP 39259 |
24.79 |
| 2026-04-10 00:00 |
08:03:31.90 |
+31:17:33.7 |
HIP 39259 |
24.52 |
| 2026-04-10 12:00 |
08:03:30.95 |
+31:17:19.2 |
HIP 39259 |
24.26 |
| 2026-04-11 00:00 |
08:03:30.03 |
+31:17:04.6 |
HIP 39259 |
24.00 |
| 2026-04-11 12:00 |
08:03:29.15 |
+31:16:49.9 |
HIP 39259 |
23.75 |
| 2026-04-12 00:00 |
08:03:28.30 |
+31:16:35.1 |
HIP 39259 |
23.51 |
| 2026-04-12 12:00 |
08:03:27.49 |
+31:16:20.3 |
HIP 39259 |
23.28 |
| 2026-04-13 00:00 |
08:03:26.72 |
+31:16:05.3 |
HIP 39259 |
23.06 |
| 2026-04-13 12:00 |
08:03:25.98 |
+31:15:50.2 |
HIP 39259 |
22.84 |
| 2026-04-14 00:00 |
08:03:25.28 |
+31:15:35.1 |
HIP 39259 |
22.64 |
| 2026-04-14 12:00 |
08:03:24.62 |
+31:15:19.8 |
HIP 39259 |
22.44 |
| 2026-04-15 00:00 |
08:03:23.99 |
+31:15:04.5 |
HIP 39259 |
22.26 |
| 2026-04-15 12:00 |
08:03:23.39 |
+31:14:49.0 |
HIP 39259 |
22.08 |
| 2026-04-16 00:00 |
08:03:22.83 |
+31:14:33.5 |
HIP 39259 |
21.91 |