| 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) |
| 2026-03-26 00:00 |
13:31:16.25 |
-04:08:13.2 |
HIP 65940 |
3.15 |
| 2026-03-26 12:00 |
13:31:09.14 |
-04:07:33.5 |
HIP 65940 |
1.43 |
| 2026-03-27 00:00 |
13:31:02.01 |
-04:06:53.8 |
HIP 65940 |
1.17 |
| 2026-03-27 12:00 |
13:30:54.86 |
-04:06:14.1 |
HIP 65940 |
2.81 |
| 2026-03-28 00:00 |
13:30:47.69 |
-04:05:34.3 |
HIP 65940 |
4.66 |
| 2026-03-28 12:00 |
13:30:40.51 |
-04:04:54.5 |
HIP 65940 |
6.55 |
| 2026-03-29 00:00 |
13:30:33.31 |
-04:04:14.7 |
HIP 65940 |
8.45 |
| 2026-03-29 12:00 |
13:30:26.10 |
-04:03:34.8 |
HIP 65940 |
10.36 |
| 2026-03-30 00:00 |
13:30:18.87 |
-04:02:55.0 |
HIP 65940 |
12.27 |
| 2026-03-30 12:00 |
13:30:11.62 |
-04:02:15.1 |
HIP 65940 |
14.20 |
| 2026-03-31 00:00 |
13:30:04.36 |
-04:01:35.3 |
HIP 65940 |
16.12 |
| 2026-03-31 12:00 |
13:29:57.09 |
-04:00:55.4 |
HIP 65940 |
18.05 |
| 2026-04-01 00:00 |
13:29:49.80 |
-04:00:15.6 |
HIP 65940 |
19.98 |
| 2026-04-01 12:00 |
13:29:42.50 |
-03:59:35.7 |
HIP 65940 |
21.92 |
| 2026-04-02 00:00 |
13:29:35.19 |
-03:58:55.9 |
HIP 65940 |
23.86 |
| 2026-04-02 12:00 |
13:29:27.86 |
-03:58:16.0 |
HIP 65940 |
25.80 |
| 2026-04-03 00:00 |
13:29:20.53 |
-03:57:36.2 |
HIP 65940 |
27.75 |
| 2026-04-03 12:00 |
13:29:13.18 |
-03:56:56.4 |
HIP 65940 |
29.70 |
| 2026-04-04 00:00 |
13:29:05.83 |
-03:56:16.6 |
HIP 65940 |
31.65 |
| 2026-04-04 12:00 |
13:28:58.46 |
-03:55:36.9 |
HIP 65751 |
32.57 |
| 2026-04-05 00:00 |
13:28:51.09 |
-03:54:57.2 |
HIP 65751 |
33.05 |
| 2026-04-05 12:00 |
13:28:43.71 |
-03:54:17.5 |
HIP 65751 |
33.64 |
| 2026-04-06 00:00 |
13:28:36.32 |
-03:53:37.8 |
HIP 65751 |
34.34 |
| 2026-04-06 12:00 |
13:28:28.92 |
-03:52:58.2 |
HIP 65751 |
35.12 |
| 2026-04-07 00:00 |
13:28:21.52 |
-03:52:18.6 |
HIP 65540 |
35.47 |
| 2026-04-07 12:00 |
13:28:14.11 |
-03:51:39.1 |
HIP 65540 |
33.51 |
| 2026-04-08 00:00 |
13:28:06.70 |
-03:50:59.6 |
HIP 65540 |
31.55 |
| 2026-04-08 12:00 |
13:27:59.28 |
-03:50:20.1 |
HIP 65540 |
29.58 |
| 2026-04-09 00:00 |
13:27:51.85 |
-03:49:40.8 |
HIP 65540 |
27.62 |
| 2026-04-09 12:00 |
13:27:44.43 |
-03:49:01.4 |
HIP 65540 |
25.66 |
| 2026-04-10 00:00 |
13:27:37.00 |
-03:48:22.2 |
HIP 65540 |
23.69 |
| 2026-04-10 12:00 |
13:27:29.57 |
-03:47:43.0 |
HIP 65540 |
21.73 |
| 2026-04-11 00:00 |
13:27:22.13 |
-03:47:03.9 |
HIP 65540 |
19.76 |
| 2026-04-11 12:00 |
13:27:14.70 |
-03:46:24.8 |
HIP 65540 |
17.80 |
| 2026-04-12 00:00 |
13:27:07.26 |
-03:45:45.9 |
HIP 65540 |
15.84 |
| 2026-04-12 12:00 |
13:26:59.83 |
-03:45:07.0 |
HIP 65540 |
13.88 |
| 2026-04-13 00:00 |
13:26:52.39 |
-03:44:28.2 |
HIP 65540 |
11.92 |
| 2026-04-13 12:00 |
13:26:44.96 |
-03:43:49.4 |
HIP 65540 |
9.96 |
| 2026-04-14 00:00 |
13:26:37.53 |
-03:43:10.8 |
HIP 65540 |
8.01 |
| 2026-04-14 12:00 |
13:26:30.10 |
-03:42:32.3 |
HIP 65540 |
6.07 |
| 2026-04-15 00:00 |
13:26:22.67 |
-03:41:53.8 |
HIP 65540 |
4.14 |
| 2026-04-15 12:00 |
13:26:15.25 |
-03:41:15.5 |
HIP 65540 |
2.29 |
| 2026-04-16 00:00 |
13:26:07.83 |
-03:40:37.3 |
HIP 65540 |
0.98 |