| 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) |
| 2026-03-26 00:00 |
12:07:30.65 |
-17:01:07.0 |
HIP 59163 |
29.50 |
| 2026-03-26 12:00 |
12:07:24.43 |
-17:00:28.4 |
HIP 59163 |
30.50 |
| 2026-03-27 00:00 |
12:07:18.21 |
-16:59:49.5 |
HIP 59163 |
31.55 |
| 2026-03-27 12:00 |
12:07:11.99 |
-16:59:10.5 |
HIP 59163 |
32.65 |
| 2026-03-28 00:00 |
12:07:05.79 |
-16:58:31.4 |
HIP 58993 |
33.62 |
| 2026-03-28 12:00 |
12:06:59.58 |
-16:57:52.0 |
HIP 58993 |
32.23 |
| 2026-03-29 00:00 |
12:06:53.39 |
-16:57:12.4 |
HIP 58993 |
30.86 |
| 2026-03-29 12:00 |
12:06:47.20 |
-16:56:32.7 |
HIP 58993 |
29.52 |
| 2026-03-30 00:00 |
12:06:41.02 |
-16:55:52.8 |
HIP 58993 |
28.20 |
| 2026-03-30 12:00 |
12:06:34.85 |
-16:55:12.7 |
HIP 58993 |
26.92 |
| 2026-03-31 00:00 |
12:06:28.69 |
-16:54:32.4 |
HIP 58993 |
25.67 |
| 2026-03-31 12:00 |
12:06:22.54 |
-16:53:52.0 |
HIP 58993 |
24.46 |
| 2026-04-01 00:00 |
12:06:16.39 |
-16:53:11.4 |
HIP 58993 |
23.31 |
| 2026-04-01 12:00 |
12:06:10.26 |
-16:52:30.6 |
HIP 58993 |
22.20 |
| 2026-04-02 00:00 |
12:06:04.14 |
-16:51:49.7 |
HIP 58993 |
21.17 |
| 2026-04-02 12:00 |
12:05:58.02 |
-16:51:08.7 |
HIP 58993 |
20.20 |
| 2026-04-03 00:00 |
12:05:51.92 |
-16:50:27.5 |
HIP 58993 |
19.32 |
| 2026-04-03 12:00 |
12:05:45.83 |
-16:49:46.1 |
HIP 58993 |
18.54 |
| 2026-04-04 00:00 |
12:05:39.76 |
-16:49:04.6 |
HIP 58993 |
17.87 |
| 2026-04-04 12:00 |
12:05:33.69 |
-16:48:22.9 |
HIP 58993 |
17.32 |
| 2026-04-05 00:00 |
12:05:27.64 |
-16:47:41.1 |
HIP 58993 |
16.90 |
| 2026-04-05 12:00 |
12:05:21.61 |
-16:46:59.2 |
HIP 58993 |
16.63 |
| 2026-04-06 00:00 |
12:05:15.59 |
-16:46:17.2 |
HIP 58993 |
16.50 |
| 2026-04-06 12:00 |
12:05:09.58 |
-16:45:35.0 |
HIP 58993 |
16.52 |
| 2026-04-07 00:00 |
12:05:03.58 |
-16:44:52.7 |
HIP 58993 |
16.70 |
| 2026-04-07 12:00 |
12:04:57.61 |
-16:44:10.2 |
HIP 58993 |
17.02 |
| 2026-04-08 00:00 |
12:04:51.64 |
-16:43:27.7 |
HIP 58993 |
17.48 |
| 2026-04-08 12:00 |
12:04:45.70 |
-16:42:45.0 |
HIP 58817 |
17.17 |
| 2026-04-09 00:00 |
12:04:39.77 |
-16:42:02.2 |
HIP 58817 |
15.61 |
| 2026-04-09 12:00 |
12:04:33.86 |
-16:41:19.3 |
HIP 58817 |
14.07 |
| 2026-04-10 00:00 |
12:04:27.97 |
-16:40:36.3 |
HIP 58817 |
12.53 |
| 2026-04-10 12:00 |
12:04:22.09 |
-16:39:53.2 |
HIP 58817 |
11.02 |
| 2026-04-11 00:00 |
12:04:16.23 |
-16:39:10.0 |
HIP 58817 |
9.52 |
| 2026-04-11 12:00 |
12:04:10.39 |
-16:38:26.7 |
HIP 58817 |
8.06 |
| 2026-04-12 00:00 |
12:04:04.57 |
-16:37:43.3 |
HIP 58817 |
6.65 |
| 2026-04-12 12:00 |
12:03:58.78 |
-16:36:59.9 |
HIP 58817 |
5.34 |
| 2026-04-13 00:00 |
12:03:53.00 |
-16:36:16.3 |
HIP 58817 |
4.20 |
| 2026-04-13 12:00 |
12:03:47.24 |
-16:35:32.7 |
HIP 58817 |
3.41 |
| 2026-04-14 00:00 |
12:03:41.50 |
-16:34:49.0 |
HIP 58817 |
3.24 |
| 2026-04-14 12:00 |
12:03:35.79 |
-16:34:05.2 |
HIP 58817 |
3.76 |
| 2026-04-15 00:00 |
12:03:30.09 |
-16:33:21.3 |
HIP 58817 |
4.75 |
| 2026-04-15 12:00 |
12:03:24.42 |
-16:32:37.4 |
HIP 58817 |
5.97 |
| 2026-04-16 00:00 |
12:03:18.77 |
-16:31:53.4 |
HIP 58766 |
5.36 |