| Parameter |
Value |
| Designation |
C/2014 C3 (NEOWISE) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2014-01-16T17:29:08.499840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:49Z |
| Obs used |
601 |
| NEO |
- |
| M1 |
15.000 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-03-28.0000000 |
| e |
0.98282842 |
| q (au) |
1.862025 |
| a (au) |
108.436469 |
| i (deg) |
151.784310 |
| Ω (om, deg) |
204.406943 |
| ω (w, deg) |
345.876795 |
| M (ma, deg) |
0.061337 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.486 + 3.306\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.486 |
| n |
3.306 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
1.033 |
| 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) |
| 2026-05-12 00:00 |
03:45:41.81 |
+38:14:01.9 |
HIP 17428 |
21.38 |
| 2026-05-12 12:00 |
03:45:46.59 |
+38:14:09.5 |
HIP 17428 |
22.20 |
| 2026-05-13 00:00 |
03:45:51.38 |
+38:14:17.4 |
HIP 17428 |
23.02 |
| 2026-05-13 12:00 |
03:45:56.17 |
+38:14:25.4 |
HIP 17428 |
23.86 |
| 2026-05-14 00:00 |
03:46:00.96 |
+38:14:33.5 |
HIP 17428 |
24.70 |
| 2026-05-14 12:00 |
03:46:05.76 |
+38:14:41.8 |
HIP 17428 |
25.55 |
| 2026-05-15 00:00 |
03:46:10.57 |
+38:14:50.3 |
HIP 17428 |
26.41 |
| 2026-05-15 12:00 |
03:46:15.37 |
+38:14:59.0 |
HIP 17558 |
26.66 |
| 2026-05-16 00:00 |
03:46:20.18 |
+38:15:07.8 |
HIP 17558 |
26.80 |
| 2026-05-16 12:00 |
03:46:24.99 |
+38:15:16.8 |
HIP 17558 |
26.97 |
| 2026-05-17 00:00 |
03:46:29.81 |
+38:15:25.9 |
HIP 17558 |
27.18 |
| 2026-05-17 12:00 |
03:46:34.62 |
+38:15:35.2 |
HIP 17558 |
27.41 |
| 2026-05-18 00:00 |
03:46:39.44 |
+38:15:44.6 |
HIP 17558 |
27.66 |
| 2026-05-18 12:00 |
03:46:44.26 |
+38:15:54.2 |
HIP 17558 |
27.95 |
| 2026-05-19 00:00 |
03:46:49.07 |
+38:16:04.0 |
HIP 17558 |
28.27 |
| 2026-05-19 12:00 |
03:46:53.89 |
+38:16:13.9 |
HIP 17558 |
28.61 |
| 2026-05-20 00:00 |
03:46:58.71 |
+38:16:23.9 |
HIP 17558 |
28.97 |
| 2026-05-20 12:00 |
03:47:03.53 |
+38:16:34.1 |
HIP 17558 |
29.36 |
| 2026-05-21 00:00 |
03:47:08.34 |
+38:16:44.5 |
HIP 17741 |
29.50 |
| 2026-05-21 12:00 |
03:47:13.16 |
+38:16:55.0 |
HIP 17741 |
29.36 |
| 2026-05-22 00:00 |
03:47:17.97 |
+38:17:05.7 |
HIP 17741 |
29.26 |
| 2026-05-22 12:00 |
03:47:22.78 |
+38:17:16.5 |
HIP 17741 |
29.20 |
| 2026-05-23 00:00 |
03:47:27.59 |
+38:17:27.4 |
HIP 17741 |
29.16 |
| 2026-05-23 12:00 |
03:47:32.40 |
+38:17:38.5 |
HIP 17741 |
29.17 |
| 2026-05-24 00:00 |
03:47:37.20 |
+38:17:49.8 |
HIP 17741 |
29.20 |
| 2026-05-24 12:00 |
03:47:42.01 |
+38:18:01.2 |
HIP 17741 |
29.27 |
| 2026-05-25 00:00 |
03:47:46.80 |
+38:18:12.7 |
HIP 17741 |
29.38 |
| 2026-05-25 12:00 |
03:47:51.60 |
+38:18:24.4 |
HIP 17741 |
29.52 |
| 2026-05-26 00:00 |
03:47:56.39 |
+38:18:36.2 |
HIP 17741 |
29.69 |
| 2026-05-26 12:00 |
03:48:01.17 |
+38:18:48.1 |
HIP 17741 |
29.89 |
| 2026-05-27 00:00 |
03:48:05.95 |
+38:19:00.2 |
HIP 17741 |
30.13 |
| 2026-05-27 12:00 |
03:48:10.73 |
+38:19:12.5 |
HIP 17741 |
30.39 |
| 2026-05-28 00:00 |
03:48:15.50 |
+38:19:24.8 |
HIP 17741 |
30.69 |
| 2026-05-28 12:00 |
03:48:20.26 |
+38:19:37.3 |
HIP 17741 |
31.01 |
| 2026-05-29 00:00 |
03:48:25.02 |
+38:19:49.9 |
HIP 17741 |
31.37 |
| 2026-05-29 12:00 |
03:48:29.77 |
+38:20:02.7 |
HIP 17741 |
31.75 |
| 2026-05-30 00:00 |
03:48:34.52 |
+38:20:15.6 |
HIP 17741 |
32.15 |
| 2026-05-30 12:00 |
03:48:39.26 |
+38:20:28.6 |
HIP 17930 |
32.56 |
| 2026-05-31 00:00 |
03:48:43.99 |
+38:20:41.8 |
HIP 17930 |
32.29 |
| 2026-05-31 12:00 |
03:48:48.72 |
+38:20:55.1 |
HIP 17930 |
32.05 |
| 2026-06-01 00:00 |
03:48:53.43 |
+38:21:08.5 |
HIP 17930 |
31.83 |
| 2026-06-01 12:00 |
03:48:58.14 |
+38:21:22.1 |
HIP 17930 |
31.65 |
| 2026-06-02 00:00 |
03:49:02.84 |
+38:21:35.7 |
HIP 17930 |
31.50 |