| 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) |
| 2026-05-12 00:00 |
11:59:05.65 |
-15:53:50.8 |
HIP 58526 |
43.99 |
| 2026-05-12 12:00 |
11:59:01.71 |
-15:53:08.6 |
HIP 58549 |
44.13 |
| 2026-05-13 00:00 |
11:58:57.80 |
-15:52:26.5 |
HIP 58549 |
43.93 |
| 2026-05-13 12:00 |
11:58:53.94 |
-15:51:44.5 |
HIP 58549 |
43.75 |
| 2026-05-14 00:00 |
11:58:50.11 |
-15:51:02.7 |
HIP 58549 |
43.61 |
| 2026-05-14 12:00 |
11:58:46.33 |
-15:50:21.0 |
HIP 58408 |
43.45 |
| 2026-05-15 00:00 |
11:58:42.58 |
-15:49:39.4 |
HIP 58408 |
42.70 |
| 2026-05-15 12:00 |
11:58:38.88 |
-15:48:58.0 |
HIP 58408 |
41.97 |
| 2026-05-16 00:00 |
11:58:35.22 |
-15:48:16.6 |
HIP 58408 |
41.27 |
| 2026-05-16 12:00 |
11:58:31.59 |
-15:47:35.5 |
HIP 58408 |
40.58 |
| 2026-05-17 00:00 |
11:58:28.01 |
-15:46:54.5 |
HIP 58408 |
39.92 |
| 2026-05-17 12:00 |
11:58:24.47 |
-15:46:13.6 |
HIP 58408 |
39.28 |
| 2026-05-18 00:00 |
11:58:20.98 |
-15:45:32.9 |
HIP 58408 |
38.66 |
| 2026-05-18 12:00 |
11:58:17.52 |
-15:44:52.4 |
HIP 58408 |
38.06 |
| 2026-05-19 00:00 |
11:58:14.11 |
-15:44:12.0 |
HIP 58408 |
37.48 |
| 2026-05-19 12:00 |
11:58:10.74 |
-15:43:31.7 |
HIP 58408 |
36.93 |
| 2026-05-20 00:00 |
11:58:07.41 |
-15:42:51.7 |
HIP 58408 |
36.40 |
| 2026-05-20 12:00 |
11:58:04.12 |
-15:42:11.8 |
HIP 58408 |
35.89 |
| 2026-05-21 00:00 |
11:58:00.88 |
-15:41:32.0 |
HIP 58408 |
35.41 |
| 2026-05-21 12:00 |
11:57:57.67 |
-15:40:52.5 |
HIP 58408 |
34.95 |
| 2026-05-22 00:00 |
11:57:54.51 |
-15:40:13.1 |
HIP 58408 |
34.51 |
| 2026-05-22 12:00 |
11:57:51.40 |
-15:39:33.9 |
HIP 58408 |
34.10 |
| 2026-05-23 00:00 |
11:57:48.33 |
-15:38:54.9 |
HIP 58408 |
33.71 |
| 2026-05-23 12:00 |
11:57:45.30 |
-15:38:16.0 |
HIP 58408 |
33.35 |
| 2026-05-24 00:00 |
11:57:42.31 |
-15:37:37.4 |
HIP 58408 |
33.01 |
| 2026-05-24 12:00 |
11:57:39.37 |
-15:36:58.9 |
HIP 58408 |
32.69 |
| 2026-05-25 00:00 |
11:57:36.47 |
-15:36:20.6 |
HIP 58408 |
32.40 |
| 2026-05-25 12:00 |
11:57:33.61 |
-15:35:42.6 |
HIP 58408 |
32.13 |
| 2026-05-26 00:00 |
11:57:30.80 |
-15:35:04.7 |
HIP 58408 |
31.89 |
| 2026-05-26 12:00 |
11:57:28.03 |
-15:34:27.0 |
HIP 58408 |
31.66 |
| 2026-05-27 00:00 |
11:57:25.30 |
-15:33:49.5 |
HIP 58408 |
31.46 |
| 2026-05-27 12:00 |
11:57:22.62 |
-15:33:12.2 |
HIP 58408 |
31.28 |
| 2026-05-28 00:00 |
11:57:19.98 |
-15:32:35.1 |
HIP 58408 |
31.12 |
| 2026-05-28 12:00 |
11:57:17.39 |
-15:31:58.2 |
HIP 58408 |
30.99 |
| 2026-05-29 00:00 |
11:57:14.84 |
-15:31:21.6 |
HIP 58408 |
30.87 |
| 2026-05-29 12:00 |
11:57:12.33 |
-15:30:45.1 |
HIP 58408 |
30.78 |
| 2026-05-30 00:00 |
11:57:09.87 |
-15:30:08.8 |
HIP 58408 |
30.70 |
| 2026-05-30 12:00 |
11:57:07.45 |
-15:29:32.8 |
HIP 58408 |
30.64 |
| 2026-05-31 00:00 |
11:57:05.08 |
-15:28:57.0 |
HIP 58408 |
30.60 |
| 2026-05-31 12:00 |
11:57:02.75 |
-15:28:21.4 |
HIP 58408 |
30.58 |
| 2026-06-01 00:00 |
11:57:00.46 |
-15:27:46.0 |
HIP 58408 |
30.58 |
| 2026-06-01 12:00 |
11:56:58.22 |
-15:27:10.8 |
HIP 58408 |
30.59 |
| 2026-06-02 00:00 |
11:56:56.02 |
-15:26:35.9 |
HIP 58408 |
30.61 |