C/2001 G1 (LONEOS)

Metadata

Parameter Value
Designation C/2001 G1 (LONEOS)
Type C
Perihelion (tp_cal, UTC) 2001-10-09T05:10:18.793920Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:30:08Z
Obs used 134
NEO -
M1 9.800
K1 4.500
PC -
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2002-01-12.0000000
e 1.00280088
q (au) 8.235531
a (au) -2940.336115
i (deg) 45.364449
Ω (om, deg) 203.891133
ω (w, deg) 343.281547
M (ma, deg) 0.000586

Magnitude

C/2001 G1 (LONEOS) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (8.467 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 8.467
n 2.000
gf 1.000
gb -0.502
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

Residuals (Piecewise)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

Start (UTC) End (UTC) a b
2002-04-04 2004-05-28 -40.2814 +37.563

log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)

Ephemeris

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-06-01 00:00 20:45:02.90 +26:07:06.8 HIP 102442 5.95
2026-06-01 12:00 20:45:01.62 +26:07:28.1 HIP 102442 6.29
2026-06-02 00:00 20:45:00.32 +26:07:49.3 HIP 102442 6.65
2026-06-02 12:00 20:44:58.99 +26:08:10.3 HIP 102442 7.02
2026-06-03 00:00 20:44:57.65 +26:08:31.1 HIP 102442 7.41
2026-06-03 12:00 20:44:56.28 +26:08:51.7 HIP 102442 7.81
2026-06-04 00:00 20:44:54.89 +26:09:12.1 HIP 102442 8.21
2026-06-04 12:00 20:44:53.47 +26:09:32.4 HIP 102442 8.63
2026-06-05 00:00 20:44:52.04 +26:09:52.4 HIP 102442 9.06
2026-06-05 12:00 20:44:50.58 +26:10:12.2 HIP 102442 9.49
2026-06-06 00:00 20:44:49.10 +26:10:31.9 HIP 102442 9.92
2026-06-06 12:00 20:44:47.60 +26:10:51.3 HIP 102442 10.37
2026-06-07 00:00 20:44:46.08 +26:11:10.5 HIP 102442 10.81
2026-06-07 12:00 20:44:44.54 +26:11:29.5 HIP 102442 11.27
2026-06-08 00:00 20:44:42.97 +26:11:48.3 HIP 102442 11.72
2026-06-08 12:00 20:44:41.39 +26:12:07.0 HIP 102442 12.18
2026-06-09 00:00 20:44:39.78 +26:12:25.4 HIP 102442 12.64
2026-06-09 12:00 20:44:38.16 +26:12:43.6 HIP 102442 13.11
2026-06-10 00:00 20:44:36.51 +26:13:01.5 HIP 102442 13.58
2026-06-10 12:00 20:44:34.84 +26:13:19.3 HIP 102442 14.05
2026-06-11 00:00 20:44:33.15 +26:13:36.9 HIP 102442 14.52
2026-06-11 12:00 20:44:31.44 +26:13:54.2 HIP 102442 15.00
2026-06-12 00:00 20:44:29.71 +26:14:11.3 HIP 102442 15.48
2026-06-12 12:00 20:44:27.96 +26:14:28.2 HIP 102442 15.96
2026-06-13 00:00 20:44:26.20 +26:14:44.9 HIP 102442 16.44
2026-06-13 12:00 20:44:24.41 +26:15:01.3 HIP 102442 16.93
2026-06-14 00:00 20:44:22.60 +26:15:17.6 HIP 102442 17.41
2026-06-14 12:00 20:44:20.77 +26:15:33.6 HIP 102442 17.90
2026-06-15 00:00 20:44:18.92 +26:15:49.4 HIP 102442 18.39
2026-06-15 12:00 20:44:17.06 +26:16:04.9 HIP 102442 18.89
2026-06-16 00:00 20:44:15.17 +26:16:20.2 HIP 102442 19.38
2026-06-16 12:00 20:44:13.27 +26:16:35.3 HIP 102442 19.87
2026-06-17 00:00 20:44:11.35 +26:16:50.2 HIP 102442 20.37
2026-06-17 12:00 20:44:09.41 +26:17:04.8 HIP 102442 20.87
2026-06-18 00:00 20:44:07.45 +26:17:19.2 HIP 102442 21.37
2026-06-18 12:00 20:44:05.47 +26:17:33.4 HIP 102442 21.87
2026-06-19 00:00 20:44:03.48 +26:17:47.3 HIP 102442 22.37
2026-06-19 12:00 20:44:01.46 +26:18:01.0 HIP 102442 22.88
2026-06-20 00:00 20:43:59.44 +26:18:14.4 HIP 102442 23.38
2026-06-20 12:00 20:43:57.39 +26:18:27.6 HIP 102442 23.89
2026-06-21 00:00 20:43:55.32 +26:18:40.6 HIP 102442 24.40
2026-06-21 12:00 20:43:53.24 +26:18:53.3 HIP 102442 24.91
2026-06-22 00:00 20:43:51.15 +26:19:05.8 HIP 102442 25.42