| Parameter |
Value |
| Designation |
C/2016 B1 (NEOWISE) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-12-04T17:12:22.285440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:22Z |
| Obs used |
522 |
| NEO |
- |
| M1 |
10.500 |
| K1 |
8.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-03-28.0000000 |
| e |
0.99239477 |
| q (au) |
3.206199 |
| a (au) |
421.578150 |
| i (deg) |
50.476159 |
| Ω (om, deg) |
231.954169 |
| ω (w, deg) |
8.559465 |
| M (ma, deg) |
0.012899 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.995 + 3.769\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.995 |
| n |
3.769 |
| gf |
1.000 |
| gb |
-0.935 |
| 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) |
| 2026-07-29 00:00 |
01:09:50.21 |
+36:15:52.0 |
HIP 5595 |
24.59 |
| 2026-07-29 12:00 |
01:09:49.05 |
+36:16:16.6 |
HIP 5595 |
24.67 |
| 2026-07-30 00:00 |
01:09:47.85 |
+36:16:41.0 |
HIP 5595 |
24.76 |
| 2026-07-30 12:00 |
01:09:46.60 |
+36:17:05.0 |
HIP 5595 |
24.88 |
| 2026-07-31 00:00 |
01:09:45.30 |
+36:17:28.8 |
HIP 5595 |
25.01 |
| 2026-07-31 12:00 |
01:09:43.95 |
+36:17:52.2 |
HIP 5595 |
25.17 |
| 2026-08-01 00:00 |
01:09:42.56 |
+36:18:15.4 |
HIP 5595 |
25.34 |
| 2026-08-01 12:00 |
01:09:41.11 |
+36:18:38.2 |
HIP 5595 |
25.53 |
| 2026-08-02 00:00 |
01:09:39.62 |
+36:19:00.7 |
HIP 5595 |
25.74 |
| 2026-08-02 12:00 |
01:09:38.08 |
+36:19:23.0 |
HIP 5595 |
25.96 |
| 2026-08-03 00:00 |
01:09:36.49 |
+36:19:44.9 |
HIP 5595 |
26.21 |
| 2026-08-03 12:00 |
01:09:34.85 |
+36:20:06.5 |
HIP 5595 |
26.47 |
| 2026-08-04 00:00 |
01:09:33.16 |
+36:20:27.8 |
HIP 5595 |
26.74 |
| 2026-08-04 12:00 |
01:09:31.43 |
+36:20:48.8 |
HIP 5595 |
27.04 |
| 2026-08-05 00:00 |
01:09:29.65 |
+36:21:09.5 |
HIP 5595 |
27.35 |
| 2026-08-05 12:00 |
01:09:27.82 |
+36:21:29.8 |
HIP 5595 |
27.67 |
| 2026-08-06 00:00 |
01:09:25.94 |
+36:21:49.9 |
HIP 5595 |
28.01 |
| 2026-08-06 12:00 |
01:09:24.01 |
+36:22:09.6 |
HIP 5595 |
28.37 |
| 2026-08-07 00:00 |
01:09:22.04 |
+36:22:28.9 |
HIP 5595 |
28.74 |
| 2026-08-07 12:00 |
01:09:20.02 |
+36:22:48.0 |
HIP 5595 |
29.12 |
| 2026-08-08 00:00 |
01:09:17.96 |
+36:23:06.7 |
HIP 5595 |
29.52 |
| 2026-08-08 12:00 |
01:09:15.84 |
+36:23:25.1 |
HIP 5595 |
29.93 |
| 2026-08-09 00:00 |
01:09:13.68 |
+36:23:43.1 |
HIP 5595 |
30.35 |
| 2026-08-09 12:00 |
01:09:11.47 |
+36:24:00.8 |
HIP 5595 |
30.79 |
| 2026-08-10 00:00 |
01:09:09.22 |
+36:24:18.1 |
HIP 5595 |
31.24 |
| 2026-08-10 12:00 |
01:09:06.92 |
+36:24:35.2 |
HIP 5595 |
31.70 |
| 2026-08-11 00:00 |
01:09:04.57 |
+36:24:51.8 |
HIP 5595 |
32.17 |
| 2026-08-11 12:00 |
01:09:02.18 |
+36:25:08.1 |
HIP 5595 |
32.65 |
| 2026-08-12 00:00 |
01:08:59.74 |
+36:25:24.1 |
HIP 5595 |
33.15 |
| 2026-08-12 12:00 |
01:08:57.25 |
+36:25:39.7 |
HIP 5595 |
33.66 |
| 2026-08-13 00:00 |
01:08:54.72 |
+36:25:55.0 |
HIP 5595 |
34.17 |
| 2026-08-13 12:00 |
01:08:52.15 |
+36:26:09.9 |
HIP 5595 |
34.70 |
| 2026-08-14 00:00 |
01:08:49.53 |
+36:26:24.4 |
HIP 5595 |
35.24 |
| 2026-08-14 12:00 |
01:08:46.86 |
+36:26:38.6 |
HIP 5595 |
35.79 |
| 2026-08-15 00:00 |
01:08:44.15 |
+36:26:52.4 |
HIP 5595 |
36.34 |
| 2026-08-15 12:00 |
01:08:41.40 |
+36:27:05.8 |
HIP 5595 |
36.91 |
| 2026-08-16 00:00 |
01:08:38.60 |
+36:27:18.9 |
HIP 5595 |
37.49 |
| 2026-08-16 12:00 |
01:08:35.75 |
+36:27:31.6 |
HIP 5595 |
38.07 |
| 2026-08-17 00:00 |
01:08:32.87 |
+36:27:44.0 |
HIP 5595 |
38.67 |
| 2026-08-17 12:00 |
01:08:29.94 |
+36:27:56.0 |
HIP 5595 |
39.27 |
| 2026-08-18 00:00 |
01:08:26.96 |
+36:28:07.6 |
HIP 5595 |
39.88 |
| 2026-08-18 12:00 |
01:08:23.95 |
+36:28:18.8 |
HIP 5595 |
40.50 |
| 2026-08-19 00:00 |
01:08:20.89 |
+36:28:29.7 |
HIP 5595 |
41.13 |