| 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
$$
M_a = (9.944 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.944 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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) |
| 2026-07-29 00:00 |
08:11:05.94 |
+30:10:19.2 |
HIP 39939 |
24.38 |
| 2026-07-29 12:00 |
08:11:09.51 |
+30:10:03.6 |
HIP 39939 |
25.19 |
| 2026-07-30 00:00 |
08:11:13.07 |
+30:09:48.1 |
HIP 39939 |
26.00 |
| 2026-07-30 12:00 |
08:11:16.63 |
+30:09:32.7 |
HIP 39939 |
26.80 |
| 2026-07-31 00:00 |
08:11:20.19 |
+30:09:17.3 |
HIP 40226 |
27.08 |
| 2026-07-31 12:00 |
08:11:23.74 |
+30:09:02.0 |
HIP 40226 |
26.67 |
| 2026-08-01 00:00 |
08:11:27.29 |
+30:08:46.8 |
HIP 40226 |
26.27 |
| 2026-08-01 12:00 |
08:11:30.83 |
+30:08:31.7 |
HIP 40226 |
25.88 |
| 2026-08-02 00:00 |
08:11:34.37 |
+30:08:16.7 |
HIP 40226 |
25.52 |
| 2026-08-02 12:00 |
08:11:37.90 |
+30:08:01.7 |
HIP 40226 |
25.18 |
| 2026-08-03 00:00 |
08:11:41.43 |
+30:07:46.8 |
HIP 40226 |
24.86 |
| 2026-08-03 12:00 |
08:11:44.95 |
+30:07:32.0 |
HIP 40226 |
24.56 |
| 2026-08-04 00:00 |
08:11:48.47 |
+30:07:17.3 |
HIP 40226 |
24.28 |
| 2026-08-04 12:00 |
08:11:51.98 |
+30:07:02.7 |
HIP 40226 |
24.03 |
| 2026-08-05 00:00 |
08:11:55.48 |
+30:06:48.2 |
HIP 40226 |
23.80 |
| 2026-08-05 12:00 |
08:11:58.98 |
+30:06:33.7 |
HIP 40226 |
23.59 |
| 2026-08-06 00:00 |
08:12:02.47 |
+30:06:19.4 |
HIP 40226 |
23.41 |
| 2026-08-06 12:00 |
08:12:05.96 |
+30:06:05.1 |
HIP 40226 |
23.25 |
| 2026-08-07 00:00 |
08:12:09.43 |
+30:05:50.9 |
HIP 40226 |
23.12 |
| 2026-08-07 12:00 |
08:12:12.90 |
+30:05:36.8 |
HIP 40226 |
23.01 |
| 2026-08-08 00:00 |
08:12:16.36 |
+30:05:22.8 |
HIP 40226 |
22.93 |
| 2026-08-08 12:00 |
08:12:19.82 |
+30:05:08.9 |
HIP 40226 |
22.87 |
| 2026-08-09 00:00 |
08:12:23.26 |
+30:04:55.1 |
HIP 40226 |
22.84 |
| 2026-08-09 12:00 |
08:12:26.70 |
+30:04:41.4 |
HIP 40226 |
22.84 |
| 2026-08-10 00:00 |
08:12:30.12 |
+30:04:27.7 |
HIP 40226 |
22.86 |
| 2026-08-10 12:00 |
08:12:33.54 |
+30:04:14.2 |
HIP 40226 |
22.91 |
| 2026-08-11 00:00 |
08:12:36.95 |
+30:04:00.7 |
HIP 40226 |
22.98 |
| 2026-08-11 12:00 |
08:12:40.35 |
+30:03:47.4 |
HIP 40226 |
23.07 |
| 2026-08-12 00:00 |
08:12:43.74 |
+30:03:34.1 |
HIP 40226 |
23.19 |
| 2026-08-12 12:00 |
08:12:47.12 |
+30:03:20.9 |
HIP 40226 |
23.33 |
| 2026-08-13 00:00 |
08:12:50.49 |
+30:03:07.9 |
HIP 40226 |
23.50 |
| 2026-08-13 12:00 |
08:12:53.84 |
+30:02:54.9 |
HIP 40226 |
23.68 |
| 2026-08-14 00:00 |
08:12:57.19 |
+30:02:42.0 |
HIP 40240 |
23.44 |
| 2026-08-14 12:00 |
08:13:00.53 |
+30:02:29.3 |
HIP 40240 |
23.16 |
| 2026-08-15 00:00 |
08:13:03.85 |
+30:02:16.6 |
HIP 40240 |
22.91 |
| 2026-08-15 12:00 |
08:13:07.17 |
+30:02:04.0 |
HIP 40240 |
22.67 |
| 2026-08-16 00:00 |
08:13:10.47 |
+30:01:51.5 |
HIP 40240 |
22.47 |
| 2026-08-16 12:00 |
08:13:13.75 |
+30:01:39.1 |
HIP 40240 |
22.28 |
| 2026-08-17 00:00 |
08:13:17.03 |
+30:01:26.9 |
HIP 40240 |
22.12 |
| 2026-08-17 12:00 |
08:13:20.29 |
+30:01:14.7 |
HIP 40240 |
21.99 |
| 2026-08-18 00:00 |
08:13:23.54 |
+30:01:02.6 |
HIP 40240 |
21.88 |
| 2026-08-18 12:00 |
08:13:26.78 |
+30:00:50.6 |
HIP 40240 |
21.80 |
| 2026-08-19 00:00 |
08:13:30.01 |
+30:00:38.8 |
HIP 40240 |
21.74 |