| 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
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) |
| 2026-07-29 00:00 |
20:40:43.05 |
+26:22:35.4 |
HIP 101959 |
14.76 |
| 2026-07-29 12:00 |
20:40:40.27 |
+26:22:28.3 |
HIP 101959 |
14.13 |
| 2026-07-30 00:00 |
20:40:37.48 |
+26:22:20.9 |
HIP 101959 |
13.49 |
| 2026-07-30 12:00 |
20:40:34.70 |
+26:22:13.3 |
HIP 101959 |
12.86 |
| 2026-07-31 00:00 |
20:40:31.92 |
+26:22:05.4 |
HIP 101959 |
12.22 |
| 2026-07-31 12:00 |
20:40:29.13 |
+26:21:57.2 |
HIP 101959 |
11.59 |
| 2026-08-01 00:00 |
20:40:26.35 |
+26:21:48.8 |
HIP 101959 |
10.95 |
| 2026-08-01 12:00 |
20:40:23.57 |
+26:21:40.2 |
HIP 101959 |
10.31 |
| 2026-08-02 00:00 |
20:40:20.78 |
+26:21:31.2 |
HIP 101959 |
9.67 |
| 2026-08-02 12:00 |
20:40:18.00 |
+26:21:22.1 |
HIP 101959 |
9.03 |
| 2026-08-03 00:00 |
20:40:15.22 |
+26:21:12.6 |
HIP 101959 |
8.39 |
| 2026-08-03 12:00 |
20:40:12.44 |
+26:21:02.9 |
HIP 101959 |
7.75 |
| 2026-08-04 00:00 |
20:40:09.66 |
+26:20:53.0 |
HIP 101959 |
7.11 |
| 2026-08-04 12:00 |
20:40:06.89 |
+26:20:42.8 |
HIP 101959 |
6.47 |
| 2026-08-05 00:00 |
20:40:04.11 |
+26:20:32.3 |
HIP 101959 |
5.82 |
| 2026-08-05 12:00 |
20:40:01.34 |
+26:20:21.6 |
HIP 101959 |
5.18 |
| 2026-08-06 00:00 |
20:39:58.57 |
+26:20:10.6 |
HIP 101959 |
4.54 |
| 2026-08-06 12:00 |
20:39:55.80 |
+26:19:59.4 |
HIP 101959 |
3.89 |
| 2026-08-07 00:00 |
20:39:53.04 |
+26:19:47.9 |
HIP 101959 |
3.25 |
| 2026-08-07 12:00 |
20:39:50.28 |
+26:19:36.2 |
HIP 101959 |
2.60 |
| 2026-08-08 00:00 |
20:39:47.52 |
+26:19:24.2 |
HIP 101959 |
1.96 |
| 2026-08-08 12:00 |
20:39:44.77 |
+26:19:12.0 |
HIP 101959 |
1.32 |
| 2026-08-09 00:00 |
20:39:42.02 |
+26:18:59.5 |
HIP 101959 |
0.70 |
| 2026-08-09 12:00 |
20:39:39.27 |
+26:18:46.8 |
HIP 101959 |
0.29 |
| 2026-08-10 00:00 |
20:39:36.53 |
+26:18:33.8 |
HIP 101959 |
0.72 |
| 2026-08-10 12:00 |
20:39:33.80 |
+26:18:20.6 |
HIP 101959 |
1.35 |
| 2026-08-11 00:00 |
20:39:31.06 |
+26:18:07.1 |
HIP 101959 |
1.99 |
| 2026-08-11 12:00 |
20:39:28.34 |
+26:17:53.4 |
HIP 101959 |
2.63 |
| 2026-08-12 00:00 |
20:39:25.62 |
+26:17:39.4 |
HIP 101959 |
3.28 |
| 2026-08-12 12:00 |
20:39:22.90 |
+26:17:25.2 |
HIP 101959 |
3.93 |
| 2026-08-13 00:00 |
20:39:20.19 |
+26:17:10.8 |
HIP 101959 |
4.58 |
| 2026-08-13 12:00 |
20:39:17.49 |
+26:16:56.1 |
HIP 101959 |
5.23 |
| 2026-08-14 00:00 |
20:39:14.79 |
+26:16:41.2 |
HIP 101959 |
5.88 |
| 2026-08-14 12:00 |
20:39:12.10 |
+26:16:26.0 |
HIP 101959 |
6.54 |
| 2026-08-15 00:00 |
20:39:09.42 |
+26:16:10.6 |
HIP 101959 |
7.19 |
| 2026-08-15 12:00 |
20:39:06.74 |
+26:15:54.9 |
HIP 101959 |
7.84 |
| 2026-08-16 00:00 |
20:39:04.07 |
+26:15:39.1 |
HIP 101959 |
8.49 |
| 2026-08-16 12:00 |
20:39:01.41 |
+26:15:23.0 |
HIP 101959 |
9.15 |
| 2026-08-17 00:00 |
20:38:58.76 |
+26:15:06.6 |
HIP 101959 |
9.80 |
| 2026-08-17 12:00 |
20:38:56.11 |
+26:14:50.0 |
HIP 101959 |
10.45 |
| 2026-08-18 00:00 |
20:38:53.47 |
+26:14:33.2 |
HIP 101959 |
11.10 |
| 2026-08-18 12:00 |
20:38:50.84 |
+26:14:16.2 |
HIP 101959 |
11.75 |
| 2026-08-19 00:00 |
20:38:48.22 |
+26:13:59.0 |
HIP 101930 |
12.25 |