417P/NEOWISE
| Parameter |
Value |
| Designation |
417P/NEOWISE |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-04-21T21:50:27.404160Z |
| Orbit solution date (soln_date, UTC) |
2025-04-09T14:06:24Z |
| Obs used |
277 |
| NEO |
- |
| M1 |
17.500 |
| K1 |
6.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-01-17T05:24:50.284800Z |
| Discovery magnitude (MPC) |
20.40 T |
| Discovery observatory (MPC) |
Z84 · Calar Alto-Schmidt |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-01-27.0000000 |
| e |
0.55459375 |
| q (au) |
1.492286 |
| a (au) |
3.350393 |
| i (deg) |
8.129115 |
| Ω (om, deg) |
111.357188 |
| ω (w, deg) |
129.397423 |
| M (ma, deg) |
228.869825 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.824 + 3.206\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.824 |
| n |
3.206 |
| gf |
0.800 |
| gb |
-0.673 |
| k |
0.914 |
| δ90 |
1.000 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
06:17:05.24 |
+25:25:46.2 |
HIP 29833 |
4.57 |
| 2026-02-03 12:00 |
06:16:46.74 |
+25:26:28.5 |
HIP 29833 |
3.77 |
| 2026-02-04 00:00 |
06:16:28.52 |
+25:27:10.3 |
HIP 29833 |
6.54 |
| 2026-02-04 12:00 |
06:16:10.57 |
+25:27:51.7 |
HIP 29833 |
10.24 |
| 2026-02-05 00:00 |
06:15:52.91 |
+25:28:32.6 |
HIP 29680 |
9.96 |
| 2026-02-05 12:00 |
06:15:35.52 |
+25:29:13.1 |
HIP 29680 |
6.16 |
| 2026-02-06 00:00 |
06:15:18.42 |
+25:29:53.2 |
HIP 29680 |
2.93 |
| 2026-02-06 12:00 |
06:15:01.61 |
+25:30:32.8 |
HIP 29680 |
3.11 |
| 2026-02-07 00:00 |
06:14:45.08 |
+25:31:12.0 |
HIP 29680 |
6.30 |
| 2026-02-07 12:00 |
06:14:28.85 |
+25:31:50.7 |
HIP 29680 |
9.85 |
| 2026-02-08 00:00 |
06:14:12.91 |
+25:32:29.1 |
HIP 29680 |
13.43 |
| 2026-02-08 12:00 |
06:13:57.27 |
+25:33:07.0 |
HIP 29680 |
16.97 |
| 2026-02-09 00:00 |
06:13:41.93 |
+25:33:44.5 |
HIP 29454 |
18.20 |
| 2026-02-09 12:00 |
06:13:26.89 |
+25:34:21.7 |
HIP 29454 |
14.95 |
| 2026-02-10 00:00 |
06:13:12.15 |
+25:34:58.4 |
HIP 29454 |
11.88 |
| 2026-02-10 12:00 |
06:12:57.72 |
+25:35:34.8 |
HIP 29454 |
9.08 |
| 2026-02-11 00:00 |
06:12:43.59 |
+25:36:10.8 |
HIP 29454 |
6.82 |
| 2026-02-11 12:00 |
06:12:29.77 |
+25:36:46.4 |
HIP 29454 |
5.63 |
| 2026-02-12 00:00 |
06:12:16.27 |
+25:37:21.6 |
HIP 29454 |
6.06 |
| 2026-02-12 12:00 |
06:12:03.07 |
+25:37:56.4 |
HIP 29454 |
7.77 |
| 2026-02-13 00:00 |
06:11:50.19 |
+25:38:30.9 |
HIP 29454 |
10.06 |
| 2026-02-13 12:00 |
06:11:37.63 |
+25:39:05.1 |
HIP 29338 |
8.35 |
| 2026-02-14 00:00 |
06:11:25.39 |
+25:39:38.9 |
HIP 29338 |
6.64 |
| 2026-02-14 12:00 |
06:11:13.46 |
+25:40:12.3 |
HIP 29338 |
5.88 |
| 2026-02-15 00:00 |
06:11:01.86 |
+25:40:45.5 |
HIP 29338 |
6.32 |
| 2026-02-15 12:00 |
06:10:50.57 |
+25:41:18.2 |
HIP 29338 |
7.67 |
| 2026-02-16 00:00 |
06:10:39.61 |
+25:41:50.7 |
HIP 29338 |
9.51 |
| 2026-02-16 12:00 |
06:10:28.98 |
+25:42:22.8 |
HIP 29338 |
11.55 |
| 2026-02-17 00:00 |
06:10:18.67 |
+25:42:54.6 |
HIP 29338 |
13.67 |
| 2026-02-17 12:00 |
06:10:08.68 |
+25:43:26.1 |
HIP 29338 |
15.80 |
| 2026-02-18 00:00 |
06:09:59.03 |
+25:43:57.3 |
HIP 29338 |
17.91 |
| 2026-02-18 12:00 |
06:09:49.70 |
+25:44:28.2 |
HIP 29158 |
17.37 |
| 2026-02-19 00:00 |
06:09:40.71 |
+25:44:58.8 |
HIP 29158 |
16.64 |
| 2026-02-19 12:00 |
06:09:32.04 |
+25:45:29.0 |
HIP 29158 |
16.17 |
| 2026-02-20 00:00 |
06:09:23.70 |
+25:45:59.0 |
HIP 29158 |
15.96 |
| 2026-02-20 12:00 |
06:09:15.70 |
+25:46:28.8 |
HIP 29123 |
15.70 |
| 2026-02-21 00:00 |
06:09:08.03 |
+25:46:58.2 |
HIP 29123 |
14.20 |
| 2026-02-21 12:00 |
06:09:00.69 |
+25:47:27.3 |
HIP 29123 |
12.82 |
| 2026-02-22 00:00 |
06:08:53.69 |
+25:47:56.2 |
HIP 29123 |
11.58 |
| 2026-02-22 12:00 |
06:08:47.01 |
+25:48:24.8 |
HIP 29123 |
10.47 |
| 2026-02-23 00:00 |
06:08:40.67 |
+25:48:53.2 |
HIP 29123 |
9.53 |
| 2026-02-23 12:00 |
06:08:34.67 |
+25:49:21.3 |
HIP 29123 |
8.77 |
| 2026-02-24 00:00 |
06:08:28.99 |
+25:49:49.1 |
HIP 29123 |
8.19 |