| Parameter |
Value |
| Designation |
C/2016 X1 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-04-29T21:10:40.776960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:28Z |
| Obs used |
289 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
9.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-09-28.0000000 |
| e |
0.99625285 |
| q (au) |
7.564181 |
| a (au) |
2018.648757 |
| i (deg) |
26.455050 |
| Ω (om, deg) |
256.425245 |
| ω (w, deg) |
224.569464 |
| M (ma, deg) |
359.997676 |
Magnitude
Scatter + Global Linear
$$
M_a = (0.331 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
0.331 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.740 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
13:59:28.14 |
-28:52:48.3 |
HIP 68176 |
27.54 |
| 2026-09-20 12:00 |
13:59:35.87 |
-28:53:00.3 |
HIP 68176 |
29.23 |
| 2026-09-21 00:00 |
13:59:43.62 |
-28:53:12.6 |
HIP 68176 |
30.93 |
| 2026-09-21 12:00 |
13:59:51.40 |
-28:53:25.3 |
HIP 68176 |
32.64 |
| 2026-09-22 00:00 |
13:59:59.20 |
-28:53:38.3 |
HIP 68176 |
34.36 |
| 2026-09-22 12:00 |
14:00:07.04 |
-28:53:51.6 |
HIP 68176 |
36.08 |
| 2026-09-23 00:00 |
14:00:14.90 |
-28:54:05.2 |
HIP 68176 |
37.81 |
| 2026-09-23 12:00 |
14:00:22.79 |
-28:54:19.1 |
HIP 68176 |
39.55 |
| 2026-09-24 00:00 |
14:00:30.71 |
-28:54:33.4 |
HIP 68176 |
41.29 |
| 2026-09-24 12:00 |
14:00:38.65 |
-28:54:48.0 |
HIP 68613 |
40.41 |
| 2026-09-25 00:00 |
14:00:46.62 |
-28:55:02.9 |
HIP 68613 |
39.05 |
| 2026-09-25 12:00 |
14:00:54.61 |
-28:55:18.0 |
HIP 68613 |
37.70 |
| 2026-09-26 00:00 |
14:01:02.63 |
-28:55:33.5 |
HIP 68613 |
36.39 |
| 2026-09-26 12:00 |
14:01:10.67 |
-28:55:49.4 |
HIP 68613 |
35.10 |
| 2026-09-27 00:00 |
14:01:18.74 |
-28:56:05.5 |
HIP 68613 |
33.86 |
| 2026-09-27 12:00 |
14:01:26.83 |
-28:56:21.9 |
HIP 68613 |
32.66 |
| 2026-09-28 00:00 |
14:01:34.95 |
-28:56:38.6 |
HIP 68613 |
31.50 |
| 2026-09-28 12:00 |
14:01:43.09 |
-28:56:55.6 |
HIP 68711 |
30.00 |
| 2026-09-29 00:00 |
14:01:51.25 |
-28:57:13.0 |
HIP 68711 |
28.25 |
| 2026-09-29 12:00 |
14:01:59.43 |
-28:57:30.6 |
HIP 68711 |
26.50 |
| 2026-09-30 00:00 |
14:02:07.64 |
-28:57:48.5 |
HIP 68711 |
24.76 |
| 2026-09-30 12:00 |
14:02:15.87 |
-28:58:06.8 |
HIP 68711 |
23.03 |
| 2026-10-01 00:00 |
14:02:24.12 |
-28:58:25.3 |
HIP 68711 |
21.31 |
| 2026-10-01 12:00 |
14:02:32.39 |
-28:58:44.1 |
HIP 68711 |
19.60 |
| 2026-10-02 00:00 |
14:02:40.68 |
-28:59:03.2 |
HIP 68711 |
17.92 |
| 2026-10-02 12:00 |
14:02:49.00 |
-28:59:22.6 |
HIP 68711 |
16.27 |
| 2026-10-03 00:00 |
14:02:57.33 |
-28:59:42.3 |
HIP 68711 |
14.67 |
| 2026-10-03 12:00 |
14:03:05.68 |
-29:00:02.3 |
HIP 68711 |
13.13 |
| 2026-10-04 00:00 |
14:03:14.06 |
-29:00:22.6 |
HIP 68711 |
11.69 |
| 2026-10-04 12:00 |
14:03:22.45 |
-29:00:43.1 |
HIP 68711 |
10.38 |
| 2026-10-05 00:00 |
14:03:30.86 |
-29:01:03.9 |
HIP 68711 |
9.26 |
| 2026-10-05 12:00 |
14:03:39.29 |
-29:01:25.1 |
HIP 68711 |
8.41 |
| 2026-10-06 00:00 |
14:03:47.74 |
-29:01:46.5 |
HIP 68711 |
7.93 |
| 2026-10-06 12:00 |
14:03:56.20 |
-29:02:08.2 |
HIP 68760 |
6.84 |
| 2026-10-07 00:00 |
14:04:04.68 |
-29:02:30.1 |
HIP 68760 |
4.95 |
| 2026-10-07 12:00 |
14:04:13.18 |
-29:02:52.4 |
HIP 68760 |
3.07 |
| 2026-10-08 00:00 |
14:04:21.70 |
-29:03:14.9 |
HIP 68760 |
1.19 |
| 2026-10-08 12:00 |
14:04:30.23 |
-29:03:37.7 |
HIP 68760 |
0.80 |
| 2026-10-09 00:00 |
14:04:38.78 |
-29:04:00.7 |
HIP 68760 |
2.67 |
| 2026-10-09 12:00 |
14:04:47.34 |
-29:04:24.1 |
HIP 68760 |
4.58 |
| 2026-10-10 00:00 |
14:04:55.91 |
-29:04:47.7 |
HIP 68760 |
6.49 |
| 2026-10-10 12:00 |
14:05:04.51 |
-29:05:11.5 |
HIP 68760 |
8.40 |
| 2026-10-11 00:00 |
14:05:13.11 |
-29:05:35.7 |
HIP 68760 |
10.32 |