| Parameter |
Value |
| Designation |
C/2015 VL62 (Lemmon-Yeung-PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-08-28T14:12:57.562560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:17Z |
| Obs used |
2115 |
| NEO |
- |
| M1 |
11.400 |
| K1 |
5.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-03-17.0000000 |
| e |
1.00203088 |
| q (au) |
2.720271 |
| a (au) |
-1339.452215 |
| i (deg) |
165.614083 |
| Ω (om, deg) |
94.546143 |
| ω (w, deg) |
128.359439 |
| M (ma, deg) |
-0.003309 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.551 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.551 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.822 |
| k |
0.999 |
| 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 |
12:03:57.27 |
-15:13:54.1 |
HIP 58841 |
3.65 |
| 2026-09-20 12:00 |
12:04:01.61 |
-15:14:19.5 |
HIP 58841 |
2.80 |
| 2026-09-21 00:00 |
12:04:05.95 |
-15:14:45.0 |
HIP 58841 |
2.23 |
| 2026-09-21 12:00 |
12:04:10.30 |
-15:15:10.7 |
HIP 58841 |
2.15 |
| 2026-09-22 00:00 |
12:04:14.64 |
-15:15:36.5 |
HIP 58841 |
2.61 |
| 2026-09-22 12:00 |
12:04:18.99 |
-15:16:02.5 |
HIP 58841 |
3.41 |
| 2026-09-23 00:00 |
12:04:23.34 |
-15:16:28.7 |
HIP 58841 |
4.35 |
| 2026-09-23 12:00 |
12:04:27.69 |
-15:16:55.0 |
HIP 58841 |
5.37 |
| 2026-09-24 00:00 |
12:04:32.03 |
-15:17:21.5 |
HIP 58841 |
6.43 |
| 2026-09-24 12:00 |
12:04:36.38 |
-15:17:48.1 |
HIP 58841 |
7.52 |
| 2026-09-25 00:00 |
12:04:40.73 |
-15:18:14.9 |
HIP 58841 |
8.61 |
| 2026-09-25 12:00 |
12:04:45.07 |
-15:18:41.9 |
HIP 58841 |
9.72 |
| 2026-09-26 00:00 |
12:04:49.41 |
-15:19:09.0 |
HIP 58841 |
10.83 |
| 2026-09-26 12:00 |
12:04:53.76 |
-15:19:36.2 |
HIP 58841 |
11.95 |
| 2026-09-27 00:00 |
12:04:58.10 |
-15:20:03.6 |
HIP 58841 |
13.07 |
| 2026-09-27 12:00 |
12:05:02.43 |
-15:20:31.2 |
HIP 58841 |
14.20 |
| 2026-09-28 00:00 |
12:05:06.77 |
-15:20:58.9 |
HIP 58841 |
15.33 |
| 2026-09-28 12:00 |
12:05:11.10 |
-15:21:26.7 |
HIP 58841 |
16.46 |
| 2026-09-29 00:00 |
12:05:15.43 |
-15:21:54.6 |
HIP 58841 |
17.59 |
| 2026-09-29 12:00 |
12:05:19.75 |
-15:22:22.8 |
HIP 58841 |
18.72 |
| 2026-09-30 00:00 |
12:05:24.07 |
-15:22:51.0 |
HIP 58841 |
19.86 |
| 2026-09-30 12:00 |
12:05:28.39 |
-15:23:19.4 |
HIP 58841 |
20.99 |
| 2026-10-01 00:00 |
12:05:32.70 |
-15:23:47.9 |
HIP 58841 |
22.13 |
| 2026-10-01 12:00 |
12:05:37.01 |
-15:24:16.5 |
HIP 58841 |
23.26 |
| 2026-10-02 00:00 |
12:05:41.31 |
-15:24:45.3 |
HIP 58841 |
24.40 |
| 2026-10-02 12:00 |
12:05:45.61 |
-15:25:14.2 |
HIP 58841 |
25.53 |
| 2026-10-03 00:00 |
12:05:49.90 |
-15:25:43.2 |
HIP 58841 |
26.67 |
| 2026-10-03 12:00 |
12:05:54.19 |
-15:26:12.4 |
HIP 58841 |
27.80 |
| 2026-10-04 00:00 |
12:05:58.47 |
-15:26:41.6 |
HIP 58841 |
28.94 |
| 2026-10-04 12:00 |
12:06:02.74 |
-15:27:11.0 |
HIP 58841 |
30.07 |
| 2026-10-05 00:00 |
12:06:07.01 |
-15:27:40.5 |
HIP 58841 |
31.21 |
| 2026-10-05 12:00 |
12:06:11.27 |
-15:28:10.2 |
HIP 58841 |
32.34 |
| 2026-10-06 00:00 |
12:06:15.52 |
-15:28:39.9 |
HIP 58841 |
33.47 |
| 2026-10-06 12:00 |
12:06:19.77 |
-15:29:09.7 |
HIP 58841 |
34.60 |
| 2026-10-07 00:00 |
12:06:24.00 |
-15:29:39.7 |
HIP 58841 |
35.73 |
| 2026-10-07 12:00 |
12:06:28.23 |
-15:30:09.8 |
HIP 58841 |
36.86 |
| 2026-10-08 00:00 |
12:06:32.45 |
-15:30:39.9 |
HIP 58841 |
37.99 |
| 2026-10-08 12:00 |
12:06:36.66 |
-15:31:10.2 |
HIP 58841 |
39.12 |
| 2026-10-09 00:00 |
12:06:40.86 |
-15:31:40.6 |
HIP 58841 |
40.25 |
| 2026-10-09 12:00 |
12:06:45.05 |
-15:32:11.0 |
HIP 58841 |
41.37 |
| 2026-10-10 00:00 |
12:06:49.23 |
-15:32:41.6 |
HIP 58841 |
42.50 |
| 2026-10-10 12:00 |
12:06:53.40 |
-15:33:12.3 |
HIP 59139 |
42.90 |
| 2026-10-11 00:00 |
12:06:57.56 |
-15:33:43.0 |
HIP 59139 |
43.17 |