| Parameter |
Value |
| Designation |
201P/LONEOS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-01-14T08:01:42.346560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:27:52Z |
| Obs used |
865 |
| NEO |
- |
| M1 |
13.000 |
| K1 |
15.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-05-08.0000000 |
| e |
0.61286098 |
| q (au) |
1.339984 |
| a (au) |
3.461247 |
| i (deg) |
7.036519 |
| Ω (om, deg) |
35.285668 |
| ω (w, deg) |
24.953960 |
| M (ma, deg) |
209.799179 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.450 + 5.551\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.450 |
| n |
5.551 |
| gf |
1.000 |
| gb |
-0.662 |
| 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 |
| 2014-07-08 |
2014-10-02 |
+4.5177 |
-1.113 |
| 2014-10-02 |
2015-01-13 |
-5.8786 |
+1.035 |
| 2015-01-16 |
2015-04-16 |
+15.3215 |
-2.697 |
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 |
18:57:18.42 |
-30:42:53.6 |
HIP 93114 |
12.27 |
| 2026-07-29 12:00 |
18:56:49.26 |
-30:43:06.1 |
HIP 92976 |
11.34 |
| 2026-07-30 00:00 |
18:56:20.27 |
-30:43:17.3 |
HIP 92976 |
10.65 |
| 2026-07-30 12:00 |
18:55:51.46 |
-30:43:27.1 |
HIP 92976 |
13.25 |
| 2026-07-31 00:00 |
18:55:22.84 |
-30:43:35.6 |
HIP 92976 |
17.71 |
| 2026-07-31 12:00 |
18:54:54.40 |
-30:43:42.8 |
HIP 92976 |
22.94 |
| 2026-08-01 00:00 |
18:54:26.16 |
-30:43:48.6 |
HIP 92735 |
20.10 |
| 2026-08-01 12:00 |
18:53:58.11 |
-30:43:53.2 |
HIP 92649 |
16.42 |
| 2026-08-02 00:00 |
18:53:30.27 |
-30:43:56.4 |
HIP 92649 |
10.44 |
| 2026-08-02 12:00 |
18:53:02.65 |
-30:43:58.4 |
HIP 92649 |
4.50 |
| 2026-08-03 00:00 |
18:52:35.24 |
-30:43:59.0 |
HIP 92649 |
1.39 |
| 2026-08-03 12:00 |
18:52:08.05 |
-30:43:58.4 |
HIP 92649 |
7.23 |
| 2026-08-04 00:00 |
18:51:41.08 |
-30:43:56.6 |
HIP 92649 |
13.02 |
| 2026-08-04 12:00 |
18:51:14.35 |
-30:43:53.4 |
HIP 92485 |
14.24 |
| 2026-08-05 00:00 |
18:50:47.86 |
-30:43:49.0 |
HIP 92485 |
14.03 |
| 2026-08-05 12:00 |
18:50:21.60 |
-30:43:43.4 |
HIP 92485 |
15.99 |
| 2026-08-06 00:00 |
18:49:55.60 |
-30:43:36.6 |
HIP 92485 |
19.42 |
| 2026-08-06 12:00 |
18:49:29.84 |
-30:43:28.5 |
HIP 92485 |
23.65 |
| 2026-08-07 00:00 |
18:49:04.35 |
-30:43:19.2 |
HIP 92184 |
24.38 |
| 2026-08-07 12:00 |
18:48:39.11 |
-30:43:08.8 |
HIP 92184 |
19.46 |
| 2026-08-08 00:00 |
18:48:14.14 |
-30:42:57.1 |
HIP 92184 |
14.94 |
| 2026-08-08 12:00 |
18:47:49.45 |
-30:42:44.3 |
HIP 92184 |
11.26 |
| 2026-08-09 00:00 |
18:47:25.03 |
-30:42:30.3 |
HIP 92184 |
9.33 |
| 2026-08-09 12:00 |
18:47:00.89 |
-30:42:15.2 |
HIP 92184 |
10.12 |
| 2026-08-10 00:00 |
18:46:37.04 |
-30:41:58.9 |
HIP 92184 |
13.07 |
| 2026-08-10 12:00 |
18:46:13.47 |
-30:41:41.5 |
HIP 92184 |
17.05 |
| 2026-08-11 00:00 |
18:45:50.21 |
-30:41:22.9 |
HIP 92184 |
21.45 |
| 2026-08-11 12:00 |
18:45:27.24 |
-30:41:03.3 |
HIP 92184 |
26.01 |
| 2026-08-12 00:00 |
18:45:04.58 |
-30:40:42.6 |
HIP 92184 |
30.64 |
| 2026-08-12 12:00 |
18:44:42.22 |
-30:40:20.8 |
HIP 92184 |
35.28 |
| 2026-08-13 00:00 |
18:44:20.17 |
-30:39:58.0 |
HIP 91753 |
35.39 |
| 2026-08-13 12:00 |
18:43:58.45 |
-30:39:34.1 |
HIP 91753 |
32.33 |
| 2026-08-14 00:00 |
18:43:37.04 |
-30:39:09.2 |
HIP 91753 |
29.70 |
| 2026-08-14 12:00 |
18:43:15.95 |
-30:38:43.2 |
HIP 91753 |
27.62 |
| 2026-08-15 00:00 |
18:42:55.19 |
-30:38:16.3 |
HIP 91612 |
25.55 |
| 2026-08-15 12:00 |
18:42:34.76 |
-30:37:48.4 |
HIP 91612 |
21.19 |
| 2026-08-16 00:00 |
18:42:14.67 |
-30:37:19.5 |
HIP 91612 |
16.93 |
| 2026-08-16 12:00 |
18:41:54.91 |
-30:36:49.6 |
HIP 91612 |
12.78 |
| 2026-08-17 00:00 |
18:41:35.49 |
-30:36:18.8 |
HIP 91612 |
8.82 |
| 2026-08-17 12:00 |
18:41:16.41 |
-30:35:47.1 |
HIP 91612 |
5.31 |
| 2026-08-18 00:00 |
18:40:57.67 |
-30:35:14.5 |
HIP 91612 |
3.55 |
| 2026-08-18 12:00 |
18:40:39.29 |
-30:34:40.9 |
HIP 91612 |
5.42 |
| 2026-08-19 00:00 |
18:40:21.25 |
-30:34:06.5 |
HIP 91612 |
8.76 |