| Parameter |
Value |
| Designation |
C/2014 W7 (Christensen) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2014-12-31T14:55:39.754560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:03Z |
| Obs used |
46 |
| NEO |
- |
| M1 |
16.300 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-12-11.0000000 |
| e |
0.86930062 |
| q (au) |
1.488259 |
| a (au) |
11.386888 |
| i (deg) |
98.313749 |
| Ω (om, deg) |
151.260997 |
| ω (w, deg) |
33.240158 |
| M (ma, deg) |
359.471035 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.710 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.710 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.988 |
| 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) |
| 2026-05-12 00:00 |
22:48:09.67 |
-31:01:26.0 |
HIP 112668 |
14.71 |
| 2026-05-12 12:00 |
22:48:12.11 |
-31:01:57.6 |
HIP 112668 |
14.69 |
| 2026-05-13 00:00 |
22:48:14.50 |
-31:02:29.6 |
HIP 112668 |
14.72 |
| 2026-05-13 12:00 |
22:48:16.83 |
-31:03:02.0 |
HIP 112668 |
14.80 |
| 2026-05-14 00:00 |
22:48:19.12 |
-31:03:34.8 |
HIP 112668 |
14.93 |
| 2026-05-14 12:00 |
22:48:21.35 |
-31:04:08.0 |
HIP 112692 |
14.39 |
| 2026-05-15 00:00 |
22:48:23.53 |
-31:04:41.6 |
HIP 112692 |
13.69 |
| 2026-05-15 12:00 |
22:48:25.66 |
-31:05:15.5 |
HIP 112692 |
13.01 |
| 2026-05-16 00:00 |
22:48:27.73 |
-31:05:49.8 |
HIP 112692 |
12.33 |
| 2026-05-16 12:00 |
22:48:29.75 |
-31:06:24.5 |
HIP 112692 |
11.66 |
| 2026-05-17 00:00 |
22:48:31.72 |
-31:06:59.5 |
HIP 112692 |
11.01 |
| 2026-05-17 12:00 |
22:48:33.64 |
-31:07:34.9 |
HIP 112692 |
10.37 |
| 2026-05-18 00:00 |
22:48:35.50 |
-31:08:10.7 |
HIP 112692 |
9.75 |
| 2026-05-18 12:00 |
22:48:37.30 |
-31:08:46.9 |
HIP 112692 |
9.16 |
| 2026-05-19 00:00 |
22:48:39.06 |
-31:09:23.4 |
HIP 112692 |
8.59 |
| 2026-05-19 12:00 |
22:48:40.76 |
-31:10:00.3 |
HIP 112692 |
8.06 |
| 2026-05-20 00:00 |
22:48:42.40 |
-31:10:37.6 |
HIP 112692 |
7.57 |
| 2026-05-20 12:00 |
22:48:43.99 |
-31:11:15.2 |
HIP 112692 |
7.13 |
| 2026-05-21 00:00 |
22:48:45.53 |
-31:11:53.2 |
HIP 112692 |
6.74 |
| 2026-05-21 12:00 |
22:48:47.01 |
-31:12:31.5 |
HIP 112692 |
6.42 |
| 2026-05-22 00:00 |
22:48:48.44 |
-31:13:10.2 |
HIP 112692 |
6.18 |
| 2026-05-22 12:00 |
22:48:49.81 |
-31:13:49.3 |
HIP 112692 |
6.03 |
| 2026-05-23 00:00 |
22:48:51.12 |
-31:14:28.7 |
HIP 112692 |
5.98 |
| 2026-05-23 12:00 |
22:48:52.38 |
-31:15:08.4 |
HIP 112692 |
6.02 |
| 2026-05-24 00:00 |
22:48:53.59 |
-31:15:48.5 |
HIP 112692 |
6.16 |
| 2026-05-24 12:00 |
22:48:54.74 |
-31:16:29.0 |
HIP 112692 |
6.39 |
| 2026-05-25 00:00 |
22:48:55.84 |
-31:17:09.7 |
HIP 112692 |
6.70 |
| 2026-05-25 12:00 |
22:48:56.88 |
-31:17:50.9 |
HIP 112692 |
7.09 |
| 2026-05-26 00:00 |
22:48:57.86 |
-31:18:32.3 |
HIP 112692 |
7.53 |
| 2026-05-26 12:00 |
22:48:58.79 |
-31:19:14.1 |
HIP 112692 |
8.03 |
| 2026-05-27 00:00 |
22:48:59.66 |
-31:19:56.2 |
HIP 112692 |
8.56 |
| 2026-05-27 12:00 |
22:49:00.48 |
-31:20:38.7 |
HIP 112692 |
9.14 |
| 2026-05-28 00:00 |
22:49:01.24 |
-31:21:21.5 |
HIP 112692 |
9.74 |
| 2026-05-28 12:00 |
22:49:01.94 |
-31:22:04.6 |
HIP 112692 |
10.37 |
| 2026-05-29 00:00 |
22:49:02.59 |
-31:22:48.0 |
HIP 112692 |
11.02 |
| 2026-05-29 12:00 |
22:49:03.18 |
-31:23:31.8 |
HIP 112692 |
11.69 |
| 2026-05-30 00:00 |
22:49:03.72 |
-31:24:15.9 |
HIP 112692 |
12.38 |
| 2026-05-30 12:00 |
22:49:04.20 |
-31:25:00.3 |
HIP 112692 |
13.08 |
| 2026-05-31 00:00 |
22:49:04.62 |
-31:25:45.0 |
HIP 112692 |
13.79 |
| 2026-05-31 12:00 |
22:49:04.99 |
-31:26:30.1 |
HIP 112692 |
14.51 |
| 2026-06-01 00:00 |
22:49:05.30 |
-31:27:15.4 |
HIP 112692 |
15.25 |
| 2026-06-01 12:00 |
22:49:05.55 |
-31:28:01.1 |
HIP 112692 |
15.99 |
| 2026-06-02 00:00 |
22:49:05.74 |
-31:28:47.0 |
HIP 112692 |
16.74 |