| Parameter |
Value |
| Designation |
C/2019 L2 (NEOWISE) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-04-02T01:58:42.522240Z |
| Orbit solution date (soln_date, UTC) |
2022-07-19T02:26:14Z |
| Obs used |
117 |
| NEO |
- |
| M1 |
10.400 |
| K1 |
27.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-06-11T18:48:21.312000Z |
| Discovery magnitude (MPC) |
18.00 R |
| Discovery observatory (MPC) |
C51 · WISE |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-07-05.0000000 |
| e |
0.93676409 |
| q (au) |
1.621540 |
| a (au) |
25.642708 |
| i (deg) |
152.187378 |
| Ω (om, deg) |
12.534296 |
| ω (w, deg) |
18.816880 |
| M (ma, deg) |
0.712861 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.141 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.141 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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) |
| 2026-06-01 00:00 |
13:16:16.06 |
-02:56:01.1 |
HIP 64721 |
11.69 |
| 2026-06-01 12:00 |
13:16:11.28 |
-02:55:44.4 |
HIP 64721 |
11.54 |
| 2026-06-02 00:00 |
13:16:06.54 |
-02:55:28.0 |
HIP 64721 |
11.51 |
| 2026-06-02 12:00 |
13:16:01.84 |
-02:55:12.0 |
HIP 64721 |
11.61 |
| 2026-06-03 00:00 |
13:15:57.19 |
-02:54:56.3 |
HIP 64721 |
11.82 |
| 2026-06-03 12:00 |
13:15:52.59 |
-02:54:40.9 |
HIP 64721 |
12.14 |
| 2026-06-04 00:00 |
13:15:48.04 |
-02:54:25.8 |
HIP 64721 |
12.56 |
| 2026-06-04 12:00 |
13:15:43.53 |
-02:54:11.1 |
HIP 64721 |
13.05 |
| 2026-06-05 00:00 |
13:15:39.07 |
-02:53:56.6 |
HIP 64721 |
13.62 |
| 2026-06-05 12:00 |
13:15:34.66 |
-02:53:42.5 |
HIP 64721 |
14.25 |
| 2026-06-06 00:00 |
13:15:30.29 |
-02:53:28.7 |
HIP 64721 |
14.92 |
| 2026-06-06 12:00 |
13:15:25.98 |
-02:53:15.2 |
HIP 64721 |
15.64 |
| 2026-06-07 00:00 |
13:15:21.71 |
-02:53:02.1 |
HIP 64721 |
16.38 |
| 2026-06-07 12:00 |
13:15:17.49 |
-02:52:49.3 |
HIP 64721 |
17.15 |
| 2026-06-08 00:00 |
13:15:13.33 |
-02:52:36.8 |
HIP 64569 |
17.71 |
| 2026-06-08 12:00 |
13:15:09.20 |
-02:52:24.6 |
HIP 64569 |
16.66 |
| 2026-06-09 00:00 |
13:15:05.13 |
-02:52:12.7 |
HIP 64569 |
15.63 |
| 2026-06-09 12:00 |
13:15:01.11 |
-02:52:01.2 |
HIP 64569 |
14.61 |
| 2026-06-10 00:00 |
13:14:57.14 |
-02:51:50.0 |
HIP 64569 |
13.60 |
| 2026-06-10 12:00 |
13:14:53.22 |
-02:51:39.1 |
HIP 64569 |
12.61 |
| 2026-06-11 00:00 |
13:14:49.35 |
-02:51:28.6 |
HIP 64569 |
11.63 |
| 2026-06-11 12:00 |
13:14:45.53 |
-02:51:18.4 |
HIP 64569 |
10.67 |
| 2026-06-12 00:00 |
13:14:41.76 |
-02:51:08.5 |
HIP 64569 |
9.72 |
| 2026-06-12 12:00 |
13:14:38.04 |
-02:50:59.0 |
HIP 64569 |
8.78 |
| 2026-06-13 00:00 |
13:14:34.37 |
-02:50:49.7 |
HIP 64569 |
7.86 |
| 2026-06-13 12:00 |
13:14:30.75 |
-02:50:40.9 |
HIP 64569 |
6.96 |
| 2026-06-14 00:00 |
13:14:27.18 |
-02:50:32.3 |
HIP 64569 |
6.07 |
| 2026-06-14 12:00 |
13:14:23.67 |
-02:50:24.1 |
HIP 64569 |
5.20 |
| 2026-06-15 00:00 |
13:14:20.20 |
-02:50:16.2 |
HIP 64569 |
4.36 |
| 2026-06-15 12:00 |
13:14:16.79 |
-02:50:08.6 |
HIP 64569 |
3.54 |
| 2026-06-16 00:00 |
13:14:13.43 |
-02:50:01.4 |
HIP 64569 |
2.77 |
| 2026-06-16 12:00 |
13:14:10.12 |
-02:49:54.5 |
HIP 64569 |
2.06 |
| 2026-06-17 00:00 |
13:14:06.87 |
-02:49:48.0 |
HIP 64569 |
1.51 |
| 2026-06-17 12:00 |
13:14:03.66 |
-02:49:41.7 |
HIP 64569 |
1.29 |
| 2026-06-18 00:00 |
13:14:00.51 |
-02:49:35.8 |
HIP 64569 |
1.53 |
| 2026-06-18 12:00 |
13:13:57.41 |
-02:49:30.3 |
HIP 64569 |
2.06 |
| 2026-06-19 00:00 |
13:13:54.37 |
-02:49:25.1 |
HIP 64569 |
2.70 |
| 2026-06-19 12:00 |
13:13:51.37 |
-02:49:20.2 |
HIP 64569 |
3.38 |
| 2026-06-20 00:00 |
13:13:48.43 |
-02:49:15.6 |
HIP 64569 |
4.08 |
| 2026-06-20 12:00 |
13:13:45.54 |
-02:49:11.4 |
HIP 64569 |
4.77 |
| 2026-06-21 00:00 |
13:13:42.71 |
-02:49:07.5 |
HIP 64569 |
5.46 |
| 2026-06-21 12:00 |
13:13:39.92 |
-02:49:03.9 |
HIP 64569 |
6.15 |
| 2026-06-22 00:00 |
13:13:37.19 |
-02:49:00.6 |
HIP 64569 |
6.82 |