| 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) |
| 2026-09-20 00:00 |
18:34:09.37 |
-29:37:00.8 |
HIP 90973 |
17.84 |
| 2026-09-20 12:00 |
18:34:15.95 |
-29:35:55.2 |
HIP 90973 |
19.54 |
| 2026-09-21 00:00 |
18:34:22.90 |
-29:34:49.4 |
HIP 90973 |
21.31 |
| 2026-09-21 12:00 |
18:34:30.22 |
-29:33:43.4 |
HIP 91172 |
21.10 |
| 2026-09-22 00:00 |
18:34:37.89 |
-29:32:37.2 |
HIP 91172 |
20.06 |
| 2026-09-22 12:00 |
18:34:45.93 |
-29:31:30.8 |
HIP 91172 |
19.12 |
| 2026-09-23 00:00 |
18:34:54.33 |
-29:30:24.1 |
HIP 91172 |
18.30 |
| 2026-09-23 12:00 |
18:35:03.09 |
-29:29:17.2 |
HIP 91172 |
17.65 |
| 2026-09-24 00:00 |
18:35:12.21 |
-29:28:10.1 |
HIP 91172 |
17.21 |
| 2026-09-24 12:00 |
18:35:21.68 |
-29:27:02.7 |
HIP 91172 |
17.03 |
| 2026-09-25 00:00 |
18:35:31.51 |
-29:25:55.2 |
HIP 91172 |
17.15 |
| 2026-09-25 12:00 |
18:35:41.69 |
-29:24:47.4 |
HIP 91172 |
17.59 |
| 2026-09-26 00:00 |
18:35:52.22 |
-29:23:39.4 |
HIP 91172 |
18.36 |
| 2026-09-26 12:00 |
18:36:03.10 |
-29:22:31.2 |
HIP 91282 |
16.79 |
| 2026-09-27 00:00 |
18:36:14.33 |
-29:21:22.8 |
HIP 91282 |
14.10 |
| 2026-09-27 12:00 |
18:36:25.91 |
-29:20:14.2 |
HIP 91282 |
11.35 |
| 2026-09-28 00:00 |
18:36:37.83 |
-29:19:05.3 |
HIP 91282 |
8.55 |
| 2026-09-28 12:00 |
18:36:50.10 |
-29:17:56.3 |
HIP 91282 |
5.72 |
| 2026-09-29 00:00 |
18:37:02.71 |
-29:16:47.0 |
HIP 91282 |
3.01 |
| 2026-09-29 12:00 |
18:37:15.66 |
-29:15:37.5 |
HIP 91282 |
1.84 |
| 2026-09-30 00:00 |
18:37:28.95 |
-29:14:27.7 |
HIP 91282 |
4.11 |
| 2026-09-30 12:00 |
18:37:42.58 |
-29:13:17.8 |
HIP 91282 |
7.14 |
| 2026-10-01 00:00 |
18:37:56.55 |
-29:12:07.6 |
HIP 91282 |
10.35 |
| 2026-10-01 12:00 |
18:38:10.85 |
-29:10:57.2 |
HIP 91282 |
13.65 |
| 2026-10-02 00:00 |
18:38:25.49 |
-29:09:46.5 |
HIP 91282 |
17.04 |
| 2026-10-02 12:00 |
18:38:40.46 |
-29:08:35.7 |
HIP 91514 |
18.90 |
| 2026-10-03 00:00 |
18:38:55.76 |
-29:07:24.6 |
HIP 91514 |
17.28 |
| 2026-10-03 12:00 |
18:39:11.40 |
-29:06:13.2 |
HIP 91514 |
16.26 |
| 2026-10-04 00:00 |
18:39:27.36 |
-29:05:01.6 |
HIP 91514 |
15.99 |
| 2026-10-04 12:00 |
18:39:43.66 |
-29:03:49.8 |
HIP 91514 |
16.56 |
| 2026-10-05 00:00 |
18:40:00.28 |
-29:02:37.7 |
HIP 91514 |
17.92 |
| 2026-10-05 12:00 |
18:40:17.22 |
-29:01:25.4 |
HIP 91640 |
17.90 |
| 2026-10-06 00:00 |
18:40:34.49 |
-29:00:12.8 |
HIP 91640 |
14.37 |
| 2026-10-06 12:00 |
18:40:52.09 |
-28:59:00.0 |
HIP 91640 |
11.08 |
| 2026-10-07 00:00 |
18:41:10.00 |
-28:57:46.9 |
HIP 91640 |
8.45 |
| 2026-10-07 12:00 |
18:41:28.24 |
-28:56:33.5 |
HIP 91640 |
7.34 |
| 2026-10-08 00:00 |
18:41:46.79 |
-28:55:19.9 |
HIP 91640 |
8.49 |
| 2026-10-08 12:00 |
18:42:05.67 |
-28:54:06.0 |
HIP 91640 |
11.30 |
| 2026-10-09 00:00 |
18:42:24.85 |
-28:52:51.8 |
HIP 91640 |
14.92 |
| 2026-10-09 12:00 |
18:42:44.36 |
-28:51:37.4 |
HIP 91640 |
18.93 |
| 2026-10-10 00:00 |
18:43:04.17 |
-28:50:22.6 |
HIP 91640 |
23.17 |
| 2026-10-10 12:00 |
18:43:24.30 |
-28:49:07.6 |
HIP 91640 |
27.57 |
| 2026-10-11 00:00 |
18:43:44.73 |
-28:47:52.3 |
HIP 91640 |
32.09 |