| 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) |
| 2026-07-29 00:00 |
03:55:49.73 |
+38:56:44.7 |
HIP 18238 |
31.53 |
| 2026-07-29 12:00 |
03:55:51.57 |
+38:57:05.3 |
HIP 18565 |
31.37 |
| 2026-07-30 00:00 |
03:55:53.37 |
+38:57:25.8 |
HIP 18565 |
31.11 |
| 2026-07-30 12:00 |
03:55:55.14 |
+38:57:46.4 |
HIP 18565 |
30.85 |
| 2026-07-31 00:00 |
03:55:56.86 |
+38:58:06.9 |
HIP 18565 |
30.61 |
| 2026-07-31 12:00 |
03:55:58.54 |
+38:58:27.4 |
HIP 18565 |
30.38 |
| 2026-08-01 00:00 |
03:56:00.19 |
+38:58:47.8 |
HIP 18565 |
30.16 |
| 2026-08-01 12:00 |
03:56:01.79 |
+38:59:08.3 |
HIP 18565 |
29.96 |
| 2026-08-02 00:00 |
03:56:03.35 |
+38:59:28.7 |
HIP 18565 |
29.77 |
| 2026-08-02 12:00 |
03:56:04.88 |
+38:59:49.1 |
HIP 18565 |
29.59 |
| 2026-08-03 00:00 |
03:56:06.36 |
+39:00:09.5 |
HIP 18565 |
29.43 |
| 2026-08-03 12:00 |
03:56:07.81 |
+39:00:29.8 |
HIP 18565 |
29.28 |
| 2026-08-04 00:00 |
03:56:09.21 |
+39:00:50.1 |
HIP 18565 |
29.14 |
| 2026-08-04 12:00 |
03:56:10.57 |
+39:01:10.4 |
HIP 18565 |
29.01 |
| 2026-08-05 00:00 |
03:56:11.90 |
+39:01:30.6 |
HIP 18565 |
28.90 |
| 2026-08-05 12:00 |
03:56:13.18 |
+39:01:50.9 |
HIP 18565 |
28.80 |
| 2026-08-06 00:00 |
03:56:14.42 |
+39:02:11.0 |
HIP 18565 |
28.72 |
| 2026-08-06 12:00 |
03:56:15.61 |
+39:02:31.2 |
HIP 18565 |
28.64 |
| 2026-08-07 00:00 |
03:56:16.77 |
+39:02:51.3 |
HIP 18565 |
28.58 |
| 2026-08-07 12:00 |
03:56:17.88 |
+39:03:11.3 |
HIP 18565 |
28.53 |
| 2026-08-08 00:00 |
03:56:18.96 |
+39:03:31.3 |
HIP 18565 |
28.50 |
| 2026-08-08 12:00 |
03:56:19.99 |
+39:03:51.3 |
HIP 18565 |
28.48 |
| 2026-08-09 00:00 |
03:56:20.98 |
+39:04:11.2 |
HIP 18565 |
28.47 |
| 2026-08-09 12:00 |
03:56:21.92 |
+39:04:31.1 |
HIP 18565 |
28.47 |
| 2026-08-10 00:00 |
03:56:22.83 |
+39:04:51.0 |
HIP 18565 |
28.48 |
| 2026-08-10 12:00 |
03:56:23.69 |
+39:05:10.7 |
HIP 18565 |
28.50 |
| 2026-08-11 00:00 |
03:56:24.50 |
+39:05:30.5 |
HIP 18565 |
28.54 |
| 2026-08-11 12:00 |
03:56:25.28 |
+39:05:50.2 |
HIP 18565 |
28.59 |
| 2026-08-12 00:00 |
03:56:26.01 |
+39:06:09.8 |
HIP 18565 |
28.64 |
| 2026-08-12 12:00 |
03:56:26.69 |
+39:06:29.3 |
HIP 18565 |
28.71 |
| 2026-08-13 00:00 |
03:56:27.34 |
+39:06:48.8 |
HIP 18565 |
28.79 |
| 2026-08-13 12:00 |
03:56:27.94 |
+39:07:08.3 |
HIP 18552 |
28.75 |
| 2026-08-14 00:00 |
03:56:28.50 |
+39:07:27.7 |
HIP 18552 |
28.45 |
| 2026-08-14 12:00 |
03:56:29.01 |
+39:07:47.0 |
HIP 18552 |
28.15 |
| 2026-08-15 00:00 |
03:56:29.48 |
+39:08:06.3 |
HIP 18552 |
27.86 |
| 2026-08-15 12:00 |
03:56:29.90 |
+39:08:25.5 |
HIP 18552 |
27.58 |
| 2026-08-16 00:00 |
03:56:30.28 |
+39:08:44.6 |
HIP 18552 |
27.31 |
| 2026-08-16 12:00 |
03:56:30.62 |
+39:09:03.6 |
HIP 18552 |
27.05 |
| 2026-08-17 00:00 |
03:56:30.91 |
+39:09:22.6 |
HIP 18552 |
26.79 |
| 2026-08-17 12:00 |
03:56:31.16 |
+39:09:41.5 |
HIP 18552 |
26.55 |
| 2026-08-18 00:00 |
03:56:31.36 |
+39:10:00.4 |
HIP 18552 |
26.31 |
| 2026-08-18 12:00 |
03:56:31.52 |
+39:10:19.1 |
HIP 18552 |
26.08 |
| 2026-08-19 00:00 |
03:56:31.63 |
+39:10:37.8 |
HIP 18552 |
25.86 |