| 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) |
| 2026-06-01 00:00 |
01:06:38.14 |
+35:06:30.2 |
HIP 5226 |
2.96 |
| 2026-06-01 12:00 |
01:06:42.31 |
+35:07:11.2 |
HIP 5226 |
1.90 |
| 2026-06-02 00:00 |
01:06:46.44 |
+35:07:52.2 |
HIP 5226 |
0.91 |
| 2026-06-02 12:00 |
01:06:50.53 |
+35:08:33.2 |
HIP 5226 |
0.62 |
| 2026-06-03 00:00 |
01:06:54.58 |
+35:09:14.2 |
HIP 5226 |
1.50 |
| 2026-06-03 12:00 |
01:06:58.60 |
+35:09:55.2 |
HIP 5226 |
2.53 |
| 2026-06-04 00:00 |
01:07:02.58 |
+35:10:36.3 |
HIP 5226 |
3.58 |
| 2026-06-04 12:00 |
01:07:06.52 |
+35:11:17.3 |
HIP 5226 |
4.62 |
| 2026-06-05 00:00 |
01:07:10.43 |
+35:11:58.3 |
HIP 5226 |
5.67 |
| 2026-06-05 12:00 |
01:07:14.30 |
+35:12:39.3 |
HIP 5226 |
6.71 |
| 2026-06-06 00:00 |
01:07:18.13 |
+35:13:20.4 |
HIP 5226 |
7.74 |
| 2026-06-06 12:00 |
01:07:21.92 |
+35:14:01.4 |
HIP 5226 |
8.77 |
| 2026-06-07 00:00 |
01:07:25.67 |
+35:14:42.4 |
HIP 5226 |
9.79 |
| 2026-06-07 12:00 |
01:07:29.38 |
+35:15:23.4 |
HIP 5226 |
10.81 |
| 2026-06-08 00:00 |
01:07:33.05 |
+35:16:04.3 |
HIP 5226 |
11.82 |
| 2026-06-08 12:00 |
01:07:36.69 |
+35:16:45.3 |
HIP 5226 |
12.83 |
| 2026-06-09 00:00 |
01:07:40.28 |
+35:17:26.2 |
HIP 5226 |
13.83 |
| 2026-06-09 12:00 |
01:07:43.84 |
+35:18:07.1 |
HIP 5226 |
14.82 |
| 2026-06-10 00:00 |
01:07:47.35 |
+35:18:48.0 |
HIP 5226 |
15.81 |
| 2026-06-10 12:00 |
01:07:50.82 |
+35:19:28.8 |
HIP 5226 |
16.79 |
| 2026-06-11 00:00 |
01:07:54.26 |
+35:20:09.6 |
HIP 5226 |
17.76 |
| 2026-06-11 12:00 |
01:07:57.65 |
+35:20:50.4 |
HIP 5226 |
18.73 |
| 2026-06-12 00:00 |
01:08:01.00 |
+35:21:31.1 |
HIP 5226 |
19.69 |
| 2026-06-12 12:00 |
01:08:04.31 |
+35:22:11.8 |
HIP 5223 |
19.89 |
| 2026-06-13 00:00 |
01:08:07.58 |
+35:22:52.4 |
HIP 5223 |
20.03 |
| 2026-06-13 12:00 |
01:08:10.80 |
+35:23:33.0 |
HIP 5223 |
20.20 |
| 2026-06-14 00:00 |
01:08:13.99 |
+35:24:13.6 |
HIP 5223 |
20.40 |
| 2026-06-14 12:00 |
01:08:17.13 |
+35:24:54.1 |
HIP 5223 |
20.64 |
| 2026-06-15 00:00 |
01:08:20.23 |
+35:25:34.5 |
HIP 5447 |
20.63 |
| 2026-06-15 12:00 |
01:08:23.28 |
+35:26:14.9 |
HIP 5447 |
19.73 |
| 2026-06-16 00:00 |
01:08:26.29 |
+35:26:55.2 |
HIP 5447 |
18.85 |
| 2026-06-16 12:00 |
01:08:29.26 |
+35:27:35.4 |
HIP 5447 |
17.98 |
| 2026-06-17 00:00 |
01:08:32.19 |
+35:28:15.6 |
HIP 5447 |
17.12 |
| 2026-06-17 12:00 |
01:08:35.07 |
+35:28:55.7 |
HIP 5447 |
16.27 |
| 2026-06-18 00:00 |
01:08:37.91 |
+35:29:35.7 |
HIP 5447 |
15.43 |
| 2026-06-18 12:00 |
01:08:40.70 |
+35:30:15.7 |
HIP 5447 |
14.61 |
| 2026-06-19 00:00 |
01:08:43.45 |
+35:30:55.5 |
HIP 5447 |
13.80 |
| 2026-06-19 12:00 |
01:08:46.16 |
+35:31:35.3 |
HIP 5447 |
13.02 |
| 2026-06-20 00:00 |
01:08:48.82 |
+35:32:15.0 |
HIP 5447 |
12.25 |
| 2026-06-20 12:00 |
01:08:51.44 |
+35:32:54.6 |
HIP 5447 |
11.50 |
| 2026-06-21 00:00 |
01:08:54.01 |
+35:33:34.2 |
HIP 5447 |
10.77 |
| 2026-06-21 12:00 |
01:08:56.54 |
+35:34:13.6 |
HIP 5447 |
10.07 |
| 2026-06-22 00:00 |
01:08:59.02 |
+35:34:52.9 |
HIP 5447 |
9.40 |