| Parameter |
Value |
| Designation |
C/2007 F1 (LONEOS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2007-10-28T18:14:50.939520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:06Z |
| Obs used |
197 |
| NEO |
- |
| M1 |
10.800 |
| K1 |
11.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2007-06-09.0000000 |
| e |
1.00008815 |
| q (au) |
0.402375 |
| a (au) |
-4564.775911 |
| i (deg) |
116.082089 |
| Ω (om, deg) |
172.886668 |
| ω (w, deg) |
153.710777 |
| M (ma, deg) |
-0.000453 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.307 + 5.138\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.307 |
| n |
5.138 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2007-03-19 |
2007-07-21 |
-2.6597 |
+1.473 |
| 2007-07-21 |
2007-10-03 |
+5.6634 |
-0.925 |
| 2007-10-03 |
2007-10-08 |
-17.3460 |
-3.750 |
| 2007-10-08 |
2007-10-16 |
-8.7273 |
-2.562 |
| 2007-10-16 |
2007-10-20 |
-2.9495 |
-0.609 |
| 2007-10-20 |
2007-10-28 |
-22.4473 |
-7.211 |
| 2007-11-03 |
2007-12-02 |
-8.8732 |
-1.511 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
11:41:14.45 |
-35:53:36.7 |
HIP 57016 |
17.47 |
| 2026-03-26 12:00 |
11:41:10.97 |
-35:53:16.3 |
HIP 57016 |
17.21 |
| 2026-03-27 00:00 |
11:41:07.48 |
-35:52:55.7 |
HIP 57016 |
16.98 |
| 2026-03-27 12:00 |
11:41:04.01 |
-35:52:34.8 |
HIP 57016 |
16.79 |
| 2026-03-28 00:00 |
11:41:00.54 |
-35:52:13.8 |
HIP 57016 |
16.62 |
| 2026-03-28 12:00 |
11:40:57.07 |
-35:51:52.5 |
HIP 57016 |
16.49 |
| 2026-03-29 00:00 |
11:40:53.62 |
-35:51:31.0 |
HIP 57016 |
16.38 |
| 2026-03-29 12:00 |
11:40:50.17 |
-35:51:09.3 |
HIP 57016 |
16.32 |
| 2026-03-30 00:00 |
11:40:46.73 |
-35:50:47.4 |
HIP 57016 |
16.28 |
| 2026-03-30 12:00 |
11:40:43.30 |
-35:50:25.2 |
HIP 57016 |
16.28 |
| 2026-03-31 00:00 |
11:40:39.88 |
-35:50:02.9 |
HIP 57016 |
16.32 |
| 2026-03-31 12:00 |
11:40:36.47 |
-35:49:40.3 |
HIP 57016 |
16.38 |
| 2026-04-01 00:00 |
11:40:33.06 |
-35:49:17.6 |
HIP 57016 |
16.49 |
| 2026-04-01 12:00 |
11:40:29.67 |
-35:48:54.6 |
HIP 57016 |
16.62 |
| 2026-04-02 00:00 |
11:40:26.28 |
-35:48:31.4 |
HIP 57016 |
16.79 |
| 2026-04-02 12:00 |
11:40:22.91 |
-35:48:08.1 |
HIP 57016 |
16.99 |
| 2026-04-03 00:00 |
11:40:19.54 |
-35:47:44.5 |
HIP 57016 |
17.22 |
| 2026-04-03 12:00 |
11:40:16.19 |
-35:47:20.7 |
HIP 57016 |
17.47 |
| 2026-04-04 00:00 |
11:40:12.84 |
-35:46:56.8 |
HIP 57016 |
17.76 |
| 2026-04-04 12:00 |
11:40:09.51 |
-35:46:32.6 |
HIP 57016 |
18.07 |
| 2026-04-05 00:00 |
11:40:06.19 |
-35:46:08.3 |
HIP 57016 |
18.41 |
| 2026-04-05 12:00 |
11:40:02.88 |
-35:45:43.7 |
HIP 57016 |
18.77 |
| 2026-04-06 00:00 |
11:39:59.58 |
-35:45:19.0 |
HIP 57016 |
19.15 |
| 2026-04-06 12:00 |
11:39:56.29 |
-35:44:54.1 |
HIP 57016 |
19.55 |
| 2026-04-07 00:00 |
11:39:53.01 |
-35:44:29.0 |
HIP 57016 |
19.97 |
| 2026-04-07 12:00 |
11:39:49.75 |
-35:44:03.7 |
HIP 57016 |
20.41 |
| 2026-04-08 00:00 |
11:39:46.50 |
-35:43:38.2 |
HIP 57016 |
20.87 |
| 2026-04-08 12:00 |
11:39:43.26 |
-35:43:12.6 |
HIP 57016 |
21.34 |
| 2026-04-09 00:00 |
11:39:40.04 |
-35:42:46.8 |
HIP 56737 |
20.96 |
| 2026-04-09 12:00 |
11:39:36.83 |
-35:42:20.8 |
HIP 56737 |
20.25 |
| 2026-04-10 00:00 |
11:39:33.63 |
-35:41:54.6 |
HIP 56737 |
19.55 |
| 2026-04-10 12:00 |
11:39:30.44 |
-35:41:28.3 |
HIP 56737 |
18.87 |
| 2026-04-11 00:00 |
11:39:27.27 |
-35:41:01.7 |
HIP 56737 |
18.19 |
| 2026-04-11 12:00 |
11:39:24.12 |
-35:40:35.1 |
HIP 56737 |
17.52 |
| 2026-04-12 00:00 |
11:39:20.98 |
-35:40:08.2 |
HIP 56737 |
16.87 |
| 2026-04-12 12:00 |
11:39:17.85 |
-35:39:41.2 |
HIP 56737 |
16.23 |
| 2026-04-13 00:00 |
11:39:14.74 |
-35:39:14.1 |
HIP 56737 |
15.61 |
| 2026-04-13 12:00 |
11:39:11.64 |
-35:38:46.7 |
HIP 56737 |
15.00 |
| 2026-04-14 00:00 |
11:39:08.56 |
-35:38:19.3 |
HIP 56737 |
14.42 |
| 2026-04-14 12:00 |
11:39:05.50 |
-35:37:51.6 |
HIP 56737 |
13.85 |
| 2026-04-15 00:00 |
11:39:02.45 |
-35:37:23.9 |
HIP 56737 |
13.31 |
| 2026-04-15 12:00 |
11:38:59.42 |
-35:36:55.9 |
HIP 56737 |
12.80 |
| 2026-04-16 00:00 |
11:38:56.40 |
-35:36:27.8 |
HIP 56737 |
12.32 |