| Parameter |
Value |
| Designation |
164P/Christensen |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-05-31T09:43:32.286720Z |
| Orbit solution date (soln_date, UTC) |
2026-05-06T14:50:18Z |
| Obs used |
1821 |
| NEO |
- |
| M1 |
14.300 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-07-05.0000000 |
| e |
0.53972883 |
| q (au) |
1.685248 |
| a (au) |
3.661424 |
| i (deg) |
16.252846 |
| Ω (om, deg) |
88.305871 |
| ω (w, deg) |
325.929222 |
| M (ma, deg) |
4.866754 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.376 + 2.183\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.376 |
| n |
2.183 |
| gf |
0.991 |
| gb |
-0.586 |
| k |
0.909 |
| δ90 |
9.999 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
10:33:17.48 |
+28:07:17.4 |
HIP 51664 |
20.77 |
| 2026-05-12 12:00 |
10:33:29.81 |
+28:03:42.6 |
HIP 51664 |
17.42 |
| 2026-05-13 00:00 |
10:33:42.38 |
+28:00:07.0 |
HIP 51664 |
14.71 |
| 2026-05-13 12:00 |
10:33:55.19 |
+27:56:30.6 |
HIP 51781 |
12.15 |
| 2026-05-14 00:00 |
10:34:08.23 |
+27:52:53.4 |
HIP 51781 |
10.39 |
| 2026-05-14 12:00 |
10:34:21.49 |
+27:49:15.5 |
HIP 51781 |
10.53 |
| 2026-05-15 00:00 |
10:34:34.99 |
+27:45:36.8 |
HIP 51781 |
12.54 |
| 2026-05-15 12:00 |
10:34:48.71 |
+27:41:57.4 |
HIP 51781 |
15.75 |
| 2026-05-16 00:00 |
10:35:02.65 |
+27:38:17.3 |
HIP 51781 |
19.62 |
| 2026-05-16 12:00 |
10:35:16.82 |
+27:34:36.5 |
HIP 51823 |
20.52 |
| 2026-05-17 00:00 |
10:35:31.21 |
+27:30:55.0 |
HIP 51893 |
15.94 |
| 2026-05-17 12:00 |
10:35:45.81 |
+27:27:12.8 |
HIP 51893 |
11.14 |
| 2026-05-18 00:00 |
10:36:00.64 |
+27:23:30.0 |
HIP 51893 |
6.51 |
| 2026-05-18 12:00 |
10:36:15.67 |
+27:19:46.5 |
HIP 51893 |
3.14 |
| 2026-05-19 00:00 |
10:36:30.92 |
+27:16:02.4 |
HIP 51893 |
5.28 |
| 2026-05-19 12:00 |
10:36:46.38 |
+27:12:17.7 |
HIP 51893 |
9.89 |
| 2026-05-20 00:00 |
10:37:02.04 |
+27:08:32.3 |
HIP 51893 |
14.86 |
| 2026-05-20 12:00 |
10:37:17.91 |
+27:04:46.4 |
HIP 51893 |
19.95 |
| 2026-05-21 00:00 |
10:37:33.98 |
+27:00:59.8 |
HIP 51893 |
25.11 |
| 2026-05-21 12:00 |
10:37:50.26 |
+26:57:12.7 |
HIP 52051 |
21.30 |
| 2026-05-22 00:00 |
10:38:06.73 |
+26:53:25.0 |
HIP 52051 |
17.02 |
| 2026-05-22 12:00 |
10:38:23.40 |
+26:49:36.8 |
HIP 52051 |
13.48 |
| 2026-05-23 00:00 |
10:38:40.26 |
+26:45:48.1 |
HIP 52051 |
11.44 |
| 2026-05-23 12:00 |
10:38:57.32 |
+26:41:58.8 |
HIP 52185 |
10.44 |
| 2026-05-24 00:00 |
10:39:14.57 |
+26:38:09.0 |
HIP 52185 |
5.87 |
| 2026-05-24 12:00 |
10:39:32.00 |
+26:34:18.7 |
HIP 52185 |
4.34 |
| 2026-05-25 00:00 |
10:39:49.62 |
+26:30:27.9 |
HIP 52185 |
7.96 |
| 2026-05-25 12:00 |
10:40:07.42 |
+26:26:36.7 |
HIP 52185 |
13.00 |
| 2026-05-26 00:00 |
10:40:25.41 |
+26:22:44.9 |
HIP 52185 |
18.37 |
| 2026-05-26 12:00 |
10:40:43.57 |
+26:18:52.7 |
HIP 52185 |
23.87 |
| 2026-05-27 00:00 |
10:41:01.92 |
+26:15:00.0 |
HIP 52422 |
27.28 |
| 2026-05-27 12:00 |
10:41:20.43 |
+26:11:06.9 |
HIP 52422 |
24.27 |
| 2026-05-28 00:00 |
10:41:39.13 |
+26:07:13.4 |
HIP 52422 |
22.29 |
| 2026-05-28 12:00 |
10:41:57.99 |
+26:03:19.4 |
HIP 52422 |
21.65 |
| 2026-05-29 00:00 |
10:42:17.02 |
+25:59:25.0 |
HIP 52348 |
19.75 |
| 2026-05-29 12:00 |
10:42:36.23 |
+25:55:30.2 |
HIP 52456 |
14.47 |
| 2026-05-30 00:00 |
10:42:55.59 |
+25:51:35.0 |
HIP 52456 |
8.61 |
| 2026-05-30 12:00 |
10:43:15.13 |
+25:47:39.4 |
HIP 52456 |
2.72 |
| 2026-05-31 00:00 |
10:43:34.82 |
+25:43:43.4 |
HIP 52456 |
3.22 |
| 2026-05-31 12:00 |
10:43:54.68 |
+25:39:47.1 |
HIP 52456 |
9.18 |
| 2026-06-01 00:00 |
10:44:14.70 |
+25:35:50.3 |
HIP 52456 |
15.17 |
| 2026-06-01 12:00 |
10:44:34.87 |
+25:31:53.2 |
HIP 52456 |
21.19 |
| 2026-06-02 00:00 |
10:44:55.20 |
+25:27:55.7 |
HIP 52681 |
20.68 |