| 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) |
| 2026-05-12 00:00 |
19:50:50.14 |
-27:43:26.1 |
HIP 97684 |
15.76 |
| 2026-05-12 12:00 |
19:50:50.34 |
-27:44:20.7 |
HIP 97684 |
16.62 |
| 2026-05-13 00:00 |
19:50:50.24 |
-27:45:16.2 |
HIP 97684 |
17.52 |
| 2026-05-13 12:00 |
19:50:49.84 |
-27:46:12.4 |
HIP 97684 |
18.45 |
| 2026-05-14 00:00 |
19:50:49.15 |
-27:47:09.5 |
HIP 97684 |
19.41 |
| 2026-05-14 12:00 |
19:50:48.16 |
-27:48:07.4 |
HIP 97684 |
20.40 |
| 2026-05-15 00:00 |
19:50:46.87 |
-27:49:06.1 |
HIP 97684 |
21.42 |
| 2026-05-15 12:00 |
19:50:45.27 |
-27:50:05.6 |
HIP 97684 |
22.47 |
| 2026-05-16 00:00 |
19:50:43.38 |
-27:51:05.9 |
HIP 97684 |
23.54 |
| 2026-05-16 12:00 |
19:50:41.18 |
-27:52:07.0 |
HIP 97707 |
23.50 |
| 2026-05-17 00:00 |
19:50:38.67 |
-27:53:08.9 |
HIP 97707 |
22.81 |
| 2026-05-17 12:00 |
19:50:35.86 |
-27:54:11.6 |
HIP 97707 |
22.18 |
| 2026-05-18 00:00 |
19:50:32.75 |
-27:55:15.1 |
HIP 97707 |
21.62 |
| 2026-05-18 12:00 |
19:50:29.32 |
-27:56:19.3 |
HIP 97707 |
21.16 |
| 2026-05-19 00:00 |
19:50:25.59 |
-27:57:24.3 |
HIP 97707 |
20.80 |
| 2026-05-19 12:00 |
19:50:21.55 |
-27:58:30.1 |
HIP 97707 |
20.56 |
| 2026-05-20 00:00 |
19:50:17.20 |
-27:59:36.7 |
HIP 97707 |
20.46 |
| 2026-05-20 12:00 |
19:50:12.54 |
-28:00:44.0 |
HIP 97707 |
20.51 |
| 2026-05-21 00:00 |
19:50:07.56 |
-28:01:52.0 |
HIP 97707 |
20.72 |
| 2026-05-21 12:00 |
19:50:02.28 |
-28:03:00.8 |
HIP 97707 |
21.09 |
| 2026-05-22 00:00 |
19:49:56.68 |
-28:04:10.4 |
HIP 97707 |
21.65 |
| 2026-05-22 12:00 |
19:49:50.77 |
-28:05:20.6 |
HIP 97505 |
21.76 |
| 2026-05-23 00:00 |
19:49:44.54 |
-28:06:31.6 |
HIP 97505 |
20.09 |
| 2026-05-23 12:00 |
19:49:38.01 |
-28:07:43.3 |
HIP 97505 |
18.41 |
| 2026-05-24 00:00 |
19:49:31.15 |
-28:08:55.7 |
HIP 97505 |
16.73 |
| 2026-05-24 12:00 |
19:49:23.98 |
-28:10:08.7 |
HIP 97505 |
15.08 |
| 2026-05-25 00:00 |
19:49:16.50 |
-28:11:22.5 |
HIP 97505 |
13.50 |
| 2026-05-25 12:00 |
19:49:08.70 |
-28:12:36.9 |
HIP 97505 |
12.06 |
| 2026-05-26 00:00 |
19:49:00.58 |
-28:13:52.0 |
HIP 97505 |
10.83 |
| 2026-05-26 12:00 |
19:48:52.14 |
-28:15:07.8 |
HIP 97505 |
9.94 |
| 2026-05-27 00:00 |
19:48:43.39 |
-28:16:24.2 |
HIP 97505 |
9.53 |
| 2026-05-27 12:00 |
19:48:34.32 |
-28:17:41.2 |
HIP 97505 |
9.72 |
| 2026-05-28 00:00 |
19:48:24.93 |
-28:18:58.9 |
HIP 97505 |
10.51 |
| 2026-05-28 12:00 |
19:48:15.22 |
-28:20:17.2 |
HIP 97401 |
10.93 |
| 2026-05-29 00:00 |
19:48:05.20 |
-28:21:36.1 |
HIP 97401 |
8.71 |
| 2026-05-29 12:00 |
19:47:54.85 |
-28:22:55.6 |
HIP 97401 |
6.70 |
| 2026-05-30 00:00 |
19:47:44.18 |
-28:24:15.6 |
HIP 97401 |
5.29 |
| 2026-05-30 12:00 |
19:47:33.20 |
-28:25:36.3 |
HIP 97401 |
5.09 |
| 2026-05-31 00:00 |
19:47:21.89 |
-28:26:57.5 |
HIP 97401 |
6.31 |
| 2026-05-31 12:00 |
19:47:10.26 |
-28:28:19.2 |
HIP 97401 |
8.43 |
| 2026-06-01 00:00 |
19:46:58.31 |
-28:29:41.5 |
HIP 97401 |
10.97 |
| 2026-06-01 12:00 |
19:46:46.04 |
-28:31:04.3 |
HIP 97401 |
13.76 |
| 2026-06-02 00:00 |
19:46:33.45 |
-28:32:27.6 |
HIP 97401 |
16.70 |