| 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) |
| 2026-09-25 00:00 |
03:54:34.75 |
+39:28:19.9 |
HIP 18313 |
23.60 |
| 2026-09-25 12:00 |
03:54:31.51 |
+39:28:28.5 |
HIP 18313 |
23.58 |
| 2026-09-26 00:00 |
03:54:28.24 |
+39:28:36.9 |
HIP 18313 |
23.58 |
| 2026-09-26 12:00 |
03:54:24.92 |
+39:28:45.2 |
HIP 18313 |
23.60 |
| 2026-09-27 00:00 |
03:54:21.57 |
+39:28:53.2 |
HIP 18313 |
23.64 |
| 2026-09-27 12:00 |
03:54:18.17 |
+39:29:01.0 |
HIP 18313 |
23.70 |
| 2026-09-28 00:00 |
03:54:14.74 |
+39:29:08.7 |
HIP 18313 |
23.80 |
| 2026-09-28 12:00 |
03:54:11.26 |
+39:29:16.1 |
HIP 18313 |
23.91 |
| 2026-09-29 00:00 |
03:54:07.74 |
+39:29:23.4 |
HIP 18313 |
24.05 |
| 2026-09-29 12:00 |
03:54:04.19 |
+39:29:30.5 |
HIP 18313 |
24.21 |
| 2026-09-30 00:00 |
03:54:00.59 |
+39:29:37.3 |
HIP 18313 |
24.40 |
| 2026-09-30 12:00 |
03:53:56.95 |
+39:29:44.0 |
HIP 18313 |
24.62 |
| 2026-10-01 00:00 |
03:53:53.28 |
+39:29:50.5 |
HIP 18313 |
24.86 |
| 2026-10-01 12:00 |
03:53:49.57 |
+39:29:56.7 |
HIP 18313 |
25.12 |
| 2026-10-02 00:00 |
03:53:45.81 |
+39:30:02.8 |
HIP 18313 |
25.41 |
| 2026-10-02 12:00 |
03:53:42.02 |
+39:30:08.6 |
HIP 18313 |
25.72 |
| 2026-10-03 00:00 |
03:53:38.19 |
+39:30:14.3 |
HIP 18074 |
25.28 |
| 2026-10-03 12:00 |
03:53:34.33 |
+39:30:19.8 |
HIP 18074 |
24.61 |
| 2026-10-04 00:00 |
03:53:30.42 |
+39:30:25.0 |
HIP 18074 |
23.95 |
| 2026-10-04 12:00 |
03:53:26.48 |
+39:30:30.0 |
HIP 18074 |
23.29 |
| 2026-10-05 00:00 |
03:53:22.50 |
+39:30:34.9 |
HIP 18074 |
22.64 |
| 2026-10-05 12:00 |
03:53:18.48 |
+39:30:39.5 |
HIP 18074 |
21.99 |
| 2026-10-06 00:00 |
03:53:14.43 |
+39:30:43.9 |
HIP 18074 |
21.34 |
| 2026-10-06 12:00 |
03:53:10.34 |
+39:30:48.1 |
HIP 18074 |
20.70 |
| 2026-10-07 00:00 |
03:53:06.21 |
+39:30:52.1 |
HIP 18074 |
20.07 |
| 2026-10-07 12:00 |
03:53:02.05 |
+39:30:55.8 |
HIP 18074 |
19.45 |
| 2026-10-08 00:00 |
03:52:57.85 |
+39:30:59.4 |
HIP 18074 |
18.84 |
| 2026-10-08 12:00 |
03:52:53.61 |
+39:31:02.7 |
HIP 18074 |
18.24 |
| 2026-10-09 00:00 |
03:52:49.34 |
+39:31:05.8 |
HIP 18074 |
17.66 |
| 2026-10-09 12:00 |
03:52:45.03 |
+39:31:08.7 |
HIP 18074 |
17.10 |
| 2026-10-10 00:00 |
03:52:40.69 |
+39:31:11.4 |
HIP 18074 |
16.56 |
| 2026-10-10 12:00 |
03:52:36.32 |
+39:31:13.9 |
HIP 18074 |
16.05 |
| 2026-10-11 00:00 |
03:52:31.91 |
+39:31:16.1 |
HIP 18074 |
15.56 |
| 2026-10-11 12:00 |
03:52:27.47 |
+39:31:18.1 |
HIP 18074 |
15.11 |
| 2026-10-12 00:00 |
03:52:22.99 |
+39:31:19.9 |
HIP 18074 |
14.69 |
| 2026-10-12 12:00 |
03:52:18.49 |
+39:31:21.5 |
HIP 18074 |
14.32 |
| 2026-10-13 00:00 |
03:52:13.94 |
+39:31:22.8 |
HIP 18074 |
13.98 |
| 2026-10-13 12:00 |
03:52:09.37 |
+39:31:23.9 |
HIP 18074 |
13.70 |
| 2026-10-14 00:00 |
03:52:04.77 |
+39:31:24.8 |
HIP 18074 |
13.48 |
| 2026-10-14 12:00 |
03:52:00.13 |
+39:31:25.5 |
HIP 18074 |
13.31 |
| 2026-10-15 00:00 |
03:51:55.46 |
+39:31:26.0 |
HIP 18074 |
13.20 |
| 2026-10-15 12:00 |
03:51:50.76 |
+39:31:26.2 |
HIP 18074 |
13.16 |
| 2026-10-16 00:00 |
03:51:46.03 |
+39:31:26.2 |
HIP 18074 |
13.18 |