| Parameter |
Value |
| Designation |
C/2001 OG108 (LONEOS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2002-03-15T04:56:44.543040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:10Z |
| Obs used |
882 |
| NEO |
Yes |
| M1 |
13.300 |
| K1 |
11.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2001-12-05.0000000 |
| e |
0.92526008 |
| q (au) |
0.994048 |
| a (au) |
13.300093 |
| i (deg) |
80.245059 |
| Ω (om, deg) |
10.555290 |
| ω (w, deg) |
116.419511 |
| M (ma, deg) |
357.963820 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.668 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.668 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.831 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2001-08-27 |
2002-03-15 |
+6.7648 |
-0.411 |
| 2002-03-15 |
2002-04-29 |
+26.2855 |
-0.105 |
| 2002-04-29 |
2002-06-05 |
-11.8897 |
+2.380 |
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 |
02:00:49.79 |
-55:06:03.7 |
HIP 9439 |
4.34 |
| 2026-03-26 12:00 |
02:00:56.23 |
-55:05:22.6 |
HIP 9439 |
4.17 |
| 2026-03-27 00:00 |
02:01:02.69 |
-55:04:41.9 |
HIP 9439 |
4.30 |
| 2026-03-27 12:00 |
02:01:09.18 |
-55:04:01.6 |
HIP 9439 |
4.71 |
| 2026-03-28 00:00 |
02:01:15.69 |
-55:03:21.8 |
HIP 9439 |
5.33 |
| 2026-03-28 12:00 |
02:01:22.22 |
-55:02:42.4 |
HIP 9439 |
6.09 |
| 2026-03-29 00:00 |
02:01:28.78 |
-55:02:03.5 |
HIP 9439 |
6.96 |
| 2026-03-29 12:00 |
02:01:35.37 |
-55:01:24.9 |
HIP 9439 |
7.89 |
| 2026-03-30 00:00 |
02:01:41.97 |
-55:00:46.9 |
HIP 9439 |
8.86 |
| 2026-03-30 12:00 |
02:01:48.60 |
-55:00:09.2 |
HIP 9439 |
9.87 |
| 2026-03-31 00:00 |
02:01:55.25 |
-54:59:32.0 |
HIP 9439 |
10.89 |
| 2026-03-31 12:00 |
02:02:01.92 |
-54:58:55.3 |
HIP 9439 |
11.93 |
| 2026-04-01 00:00 |
02:02:08.62 |
-54:58:19.0 |
HIP 9439 |
12.99 |
| 2026-04-01 12:00 |
02:02:15.33 |
-54:57:43.1 |
HIP 9439 |
14.05 |
| 2026-04-02 00:00 |
02:02:22.07 |
-54:57:07.7 |
HIP 9439 |
15.12 |
| 2026-04-02 12:00 |
02:02:28.83 |
-54:56:32.7 |
HIP 9439 |
16.20 |
| 2026-04-03 00:00 |
02:02:35.60 |
-54:55:58.2 |
HIP 9439 |
17.27 |
| 2026-04-03 12:00 |
02:02:42.40 |
-54:55:24.1 |
HIP 9685 |
16.38 |
| 2026-04-04 00:00 |
02:02:49.21 |
-54:54:50.5 |
HIP 9685 |
15.34 |
| 2026-04-04 12:00 |
02:02:56.04 |
-54:54:17.4 |
HIP 9685 |
14.30 |
| 2026-04-05 00:00 |
02:03:02.89 |
-54:53:44.7 |
HIP 9685 |
13.28 |
| 2026-04-05 12:00 |
02:03:09.76 |
-54:53:12.5 |
HIP 9685 |
12.27 |
| 2026-04-06 00:00 |
02:03:16.65 |
-54:52:40.7 |
HIP 9685 |
11.28 |
| 2026-04-06 12:00 |
02:03:23.55 |
-54:52:09.4 |
HIP 9685 |
10.31 |
| 2026-04-07 00:00 |
02:03:30.47 |
-54:51:38.6 |
HIP 9685 |
9.37 |
| 2026-04-07 12:00 |
02:03:37.40 |
-54:51:08.2 |
HIP 9685 |
8.48 |
| 2026-04-08 00:00 |
02:03:44.35 |
-54:50:38.3 |
HIP 9685 |
7.64 |
| 2026-04-08 12:00 |
02:03:51.32 |
-54:50:08.9 |
HIP 9685 |
6.87 |
| 2026-04-09 00:00 |
02:03:58.30 |
-54:49:39.9 |
HIP 9685 |
6.20 |
| 2026-04-09 12:00 |
02:04:05.29 |
-54:49:11.4 |
HIP 9685 |
5.66 |
| 2026-04-10 00:00 |
02:04:12.30 |
-54:48:43.4 |
HIP 9685 |
5.30 |
| 2026-04-10 12:00 |
02:04:19.32 |
-54:48:15.9 |
HIP 9685 |
5.16 |
| 2026-04-11 00:00 |
02:04:26.36 |
-54:47:48.9 |
HIP 9685 |
5.23 |
| 2026-04-11 12:00 |
02:04:33.40 |
-54:47:22.3 |
HIP 9685 |
5.53 |
| 2026-04-12 00:00 |
02:04:40.46 |
-54:46:56.2 |
HIP 9685 |
6.01 |
| 2026-04-12 12:00 |
02:04:47.53 |
-54:46:30.6 |
HIP 9685 |
6.64 |
| 2026-04-13 00:00 |
02:04:54.62 |
-54:46:05.5 |
HIP 9685 |
7.37 |
| 2026-04-13 12:00 |
02:05:01.71 |
-54:45:40.9 |
HIP 9685 |
8.17 |
| 2026-04-14 00:00 |
02:05:08.81 |
-54:45:16.8 |
HIP 9685 |
9.04 |
| 2026-04-14 12:00 |
02:05:15.93 |
-54:44:53.1 |
HIP 9685 |
9.94 |
| 2026-04-15 00:00 |
02:05:23.05 |
-54:44:30.0 |
HIP 9685 |
10.88 |
| 2026-04-15 12:00 |
02:05:30.18 |
-54:44:07.3 |
HIP 9685 |
11.84 |
| 2026-04-16 00:00 |
02:05:37.32 |
-54:43:45.2 |
HIP 9685 |
12.81 |