| 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) |
| 2026-09-20 00:00 |
20:36:28.10 |
+25:48:55.4 |
HIP 101641 |
6.00 |
| 2026-09-20 12:00 |
20:36:26.47 |
+25:48:27.0 |
HIP 101641 |
6.08 |
| 2026-09-21 00:00 |
20:36:24.87 |
+25:47:58.4 |
HIP 101641 |
6.22 |
| 2026-09-21 12:00 |
20:36:23.30 |
+25:47:29.8 |
HIP 101641 |
6.42 |
| 2026-09-22 00:00 |
20:36:21.74 |
+25:47:01.0 |
HIP 101641 |
6.66 |
| 2026-09-22 12:00 |
20:36:20.20 |
+25:46:32.2 |
HIP 101641 |
6.95 |
| 2026-09-23 00:00 |
20:36:18.69 |
+25:46:03.2 |
HIP 101641 |
7.29 |
| 2026-09-23 12:00 |
20:36:17.20 |
+25:45:34.2 |
HIP 101641 |
7.65 |
| 2026-09-24 00:00 |
20:36:15.73 |
+25:45:05.1 |
HIP 101641 |
8.05 |
| 2026-09-24 12:00 |
20:36:14.28 |
+25:44:35.8 |
HIP 101641 |
8.47 |
| 2026-09-25 00:00 |
20:36:12.85 |
+25:44:06.5 |
HIP 101641 |
8.91 |
| 2026-09-25 12:00 |
20:36:11.45 |
+25:43:37.1 |
HIP 101641 |
9.36 |
| 2026-09-26 00:00 |
20:36:10.07 |
+25:43:07.6 |
HIP 101641 |
9.84 |
| 2026-09-26 12:00 |
20:36:08.71 |
+25:42:38.1 |
HIP 101641 |
10.32 |
| 2026-09-27 00:00 |
20:36:07.37 |
+25:42:08.4 |
HIP 101641 |
10.82 |
| 2026-09-27 12:00 |
20:36:06.06 |
+25:41:38.7 |
HIP 101641 |
11.32 |
| 2026-09-28 00:00 |
20:36:04.77 |
+25:41:08.9 |
HIP 101641 |
11.84 |
| 2026-09-28 12:00 |
20:36:03.50 |
+25:40:39.0 |
HIP 101627 |
12.12 |
| 2026-09-29 00:00 |
20:36:02.26 |
+25:40:09.1 |
HIP 101627 |
11.58 |
| 2026-09-29 12:00 |
20:36:01.04 |
+25:39:39.1 |
HIP 101627 |
11.05 |
| 2026-09-30 00:00 |
20:35:59.84 |
+25:39:09.0 |
HIP 101627 |
10.51 |
| 2026-09-30 12:00 |
20:35:58.66 |
+25:38:38.9 |
HIP 101627 |
9.98 |
| 2026-10-01 00:00 |
20:35:57.51 |
+25:38:08.7 |
HIP 101627 |
9.46 |
| 2026-10-01 12:00 |
20:35:56.39 |
+25:37:38.4 |
HIP 101627 |
8.93 |
| 2026-10-02 00:00 |
20:35:55.28 |
+25:37:08.1 |
HIP 101627 |
8.42 |
| 2026-10-02 12:00 |
20:35:54.20 |
+25:36:37.7 |
HIP 101627 |
7.91 |
| 2026-10-03 00:00 |
20:35:53.15 |
+25:36:07.2 |
HIP 101627 |
7.40 |
| 2026-10-03 12:00 |
20:35:52.12 |
+25:35:36.8 |
HIP 101627 |
6.90 |
| 2026-10-04 00:00 |
20:35:51.11 |
+25:35:06.2 |
HIP 101627 |
6.41 |
| 2026-10-04 12:00 |
20:35:50.13 |
+25:34:35.6 |
HIP 101627 |
5.93 |
| 2026-10-05 00:00 |
20:35:49.17 |
+25:34:05.0 |
HIP 101627 |
5.47 |
| 2026-10-05 12:00 |
20:35:48.23 |
+25:33:34.3 |
HIP 101627 |
5.02 |
| 2026-10-06 00:00 |
20:35:47.32 |
+25:33:03.6 |
HIP 101627 |
4.59 |
| 2026-10-06 12:00 |
20:35:46.44 |
+25:32:32.9 |
HIP 101627 |
4.18 |
| 2026-10-07 00:00 |
20:35:45.58 |
+25:32:02.1 |
HIP 101627 |
3.81 |
| 2026-10-07 12:00 |
20:35:44.74 |
+25:31:31.3 |
HIP 101627 |
3.48 |
| 2026-10-08 00:00 |
20:35:43.93 |
+25:31:00.4 |
HIP 101627 |
3.21 |
| 2026-10-08 12:00 |
20:35:43.15 |
+25:30:29.6 |
HIP 101627 |
3.01 |
| 2026-10-09 00:00 |
20:35:42.39 |
+25:29:58.7 |
HIP 101627 |
2.89 |
| 2026-10-09 12:00 |
20:35:41.66 |
+25:29:27.8 |
HIP 101627 |
2.87 |
| 2026-10-10 00:00 |
20:35:40.95 |
+25:28:56.8 |
HIP 101627 |
2.94 |
| 2026-10-10 12:00 |
20:35:40.27 |
+25:28:25.9 |
HIP 101627 |
3.10 |
| 2026-10-11 00:00 |
20:35:39.61 |
+25:27:54.9 |
HIP 101627 |
3.33 |