C/2001 OG108 (LONEOS)

Metadata

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

C/2001 OG108 (LONEOS) · Magnitude (Full range)

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 +6.7643 -0.411
2002-03-15 2002-04-29 +26.2855 -0.105
2002-04-29 2002-06-05 -11.8899 +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)
2026-07-29 00:00 02:22:46.07 -56:16:23.7 HIP 11123 16.59
2026-07-29 12:00 02:22:46.12 -56:17:25.4 HIP 11123 15.58
2026-07-30 00:00 02:22:46.10 -56:18:27.2 HIP 11123 14.57
2026-07-30 12:00 02:22:46.01 -56:19:29.0 HIP 11123 13.57
2026-07-31 00:00 02:22:45.86 -56:20:31.0 HIP 11123 12.58
2026-07-31 12:00 02:22:45.64 -56:21:33.0 HIP 11123 11.59
2026-08-01 00:00 02:22:45.35 -56:22:35.2 HIP 11123 10.61
2026-08-01 12:00 02:22:45.00 -56:23:37.3 HIP 11123 9.65
2026-08-02 00:00 02:22:44.58 -56:24:39.6 HIP 11123 8.70
2026-08-02 12:00 02:22:44.09 -56:25:41.9 HIP 11123 7.78
2026-08-03 00:00 02:22:43.54 -56:26:44.3 HIP 11123 6.90
2026-08-03 12:00 02:22:42.91 -56:27:46.8 HIP 11123 6.08
2026-08-04 00:00 02:22:42.22 -56:28:49.3 HIP 11123 5.35
2026-08-04 12:00 02:22:41.46 -56:29:51.8 HIP 11123 4.73
2026-08-05 00:00 02:22:40.64 -56:30:54.4 HIP 11123 4.30
2026-08-05 12:00 02:22:39.74 -56:31:57.1 HIP 11123 4.11
2026-08-06 00:00 02:22:38.78 -56:32:59.7 HIP 11123 4.19
2026-08-06 12:00 02:22:37.75 -56:34:02.4 HIP 11123 4.52
2026-08-07 00:00 02:22:36.65 -56:35:05.1 HIP 11123 5.07
2026-08-07 12:00 02:22:35.48 -56:36:07.9 HIP 11123 5.77
2026-08-08 00:00 02:22:34.24 -56:37:10.6 HIP 11123 6.58
2026-08-08 12:00 02:22:32.94 -56:38:13.4 HIP 11123 7.45
2026-08-09 00:00 02:22:31.56 -56:39:16.1 HIP 11123 8.37
2026-08-09 12:00 02:22:30.12 -56:40:18.9 HIP 11123 9.33
2026-08-10 00:00 02:22:28.61 -56:41:21.6 HIP 11123 10.31
2026-08-10 12:00 02:22:27.03 -56:42:24.4 HIP 11145 10.08
2026-08-11 00:00 02:22:25.38 -56:43:27.1 HIP 11145 9.64
2026-08-11 12:00 02:22:23.66 -56:44:29.8 HIP 11145 9.31
2026-08-12 00:00 02:22:21.87 -56:45:32.4 HIP 11145 9.10
2026-08-12 12:00 02:22:20.01 -56:46:35.1 HIP 11145 9.02
2026-08-13 00:00 02:22:18.08 -56:47:37.6 HIP 11145 9.08
2026-08-13 12:00 02:22:16.09 -56:48:40.2 HIP 11145 9.28
2026-08-14 00:00 02:22:14.02 -56:49:42.7 HIP 11145 9.60
2026-08-14 12:00 02:22:11.88 -56:50:45.1 HIP 11145 10.04
2026-08-15 00:00 02:22:09.68 -56:51:47.5 HIP 11145 10.58
2026-08-15 12:00 02:22:07.41 -56:52:49.8 HIP 11145 11.21
2026-08-16 00:00 02:22:05.06 -56:53:52.0 HIP 11145 11.91
2026-08-16 12:00 02:22:02.65 -56:54:54.1 HIP 11145 12.67
2026-08-17 00:00 02:22:00.17 -56:55:56.2 HIP 11145 13.48
2026-08-17 12:00 02:21:57.62 -56:56:58.1 HIP 11145 14.34
2026-08-18 00:00 02:21:55.01 -56:58:00.0 HIP 11145 15.23
2026-08-18 12:00 02:21:52.32 -56:59:01.8 HIP 11145 16.15
2026-08-19 00:00 02:21:49.57 -57:00:03.4 HIP 11145 17.10