| Parameter |
Value |
| Designation |
422P/Christensen |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2006-05-27T22:01:25.478400Z |
| Orbit solution date (soln_date, UTC) |
2024-07-07T00:42:21Z |
| Obs used |
281 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
18.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2021-06-05T07:45:40.032000Z |
| Discovery magnitude (MPC) |
18.60 R |
| Discovery observatory (MPC) |
Y00 · SONEAR Observatory, Oliveira |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-12-16.0000000 |
| e |
0.50606921 |
| q (au) |
3.092805 |
| a (au) |
6.261616 |
| i (deg) |
39.588451 |
| Ω (om, deg) |
36.088366 |
| ω (w, deg) |
305.989857 |
| M (ma, deg) |
173.555768 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.906 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.906 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.501 |
| k |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2021-06-05 |
2022-11-29 |
+36.3090 |
-19.481 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
10:25:16.30 |
+49:24:34.4 |
HIP 50909 |
18.19 |
| 2026-09-20 12:00 |
10:25:37.99 |
+49:24:06.3 |
HIP 50909 |
21.36 |
| 2026-09-21 00:00 |
10:25:59.62 |
+49:23:39.1 |
HIP 50909 |
24.62 |
| 2026-09-21 12:00 |
10:26:21.20 |
+49:23:12.7 |
HIP 50909 |
27.94 |
| 2026-09-22 00:00 |
10:26:42.72 |
+49:22:47.3 |
HIP 51247 |
28.21 |
| 2026-09-22 12:00 |
10:27:04.19 |
+49:22:22.8 |
HIP 51247 |
26.38 |
| 2026-09-23 00:00 |
10:27:25.60 |
+49:21:59.3 |
HIP 51247 |
24.92 |
| 2026-09-23 12:00 |
10:27:46.96 |
+49:21:36.6 |
HIP 51247 |
23.92 |
| 2026-09-24 00:00 |
10:28:08.25 |
+49:21:14.9 |
HIP 51247 |
23.42 |
| 2026-09-24 12:00 |
10:28:29.49 |
+49:20:54.1 |
HIP 51247 |
23.46 |
| 2026-09-25 00:00 |
10:28:50.67 |
+49:20:34.2 |
HIP 51247 |
24.02 |
| 2026-09-25 12:00 |
10:29:11.80 |
+49:20:15.3 |
HIP 51247 |
25.06 |
| 2026-09-26 00:00 |
10:29:32.86 |
+49:19:57.3 |
HIP 51483 |
24.75 |
| 2026-09-26 12:00 |
10:29:53.86 |
+49:19:40.2 |
HIP 51483 |
23.35 |
| 2026-09-27 00:00 |
10:30:14.80 |
+49:19:24.1 |
HIP 51483 |
22.37 |
| 2026-09-27 12:00 |
10:30:35.68 |
+49:19:08.9 |
HIP 51483 |
21.87 |
| 2026-09-28 00:00 |
10:30:56.49 |
+49:18:54.6 |
HIP 51483 |
21.88 |
| 2026-09-28 12:00 |
10:31:17.25 |
+49:18:41.3 |
HIP 51649 |
20.04 |
| 2026-09-29 00:00 |
10:31:37.94 |
+49:18:29.0 |
HIP 51649 |
16.95 |
| 2026-09-29 12:00 |
10:31:58.56 |
+49:18:17.6 |
HIP 51649 |
14.00 |
| 2026-09-30 00:00 |
10:32:19.13 |
+49:18:07.2 |
HIP 51649 |
11.32 |
| 2026-09-30 12:00 |
10:32:39.62 |
+49:17:57.7 |
HIP 51649 |
9.12 |
| 2026-10-01 00:00 |
10:33:00.05 |
+49:17:49.2 |
HIP 51649 |
7.80 |
| 2026-10-01 12:00 |
10:33:20.42 |
+49:17:41.6 |
HIP 51649 |
7.82 |
| 2026-10-02 00:00 |
10:33:40.72 |
+49:17:35.1 |
HIP 51700 |
6.62 |
| 2026-10-02 12:00 |
10:34:00.94 |
+49:17:29.5 |
HIP 51700 |
6.57 |
| 2026-10-03 00:00 |
10:34:21.10 |
+49:17:24.9 |
HIP 51700 |
8.03 |
| 2026-10-03 12:00 |
10:34:41.19 |
+49:17:21.2 |
HIP 51700 |
10.37 |
| 2026-10-04 00:00 |
10:35:01.21 |
+49:17:18.6 |
HIP 51750 |
12.70 |
| 2026-10-04 12:00 |
10:35:21.16 |
+49:17:17.0 |
HIP 51750 |
14.64 |
| 2026-10-05 00:00 |
10:35:41.04 |
+49:17:16.3 |
HIP 51750 |
16.98 |
| 2026-10-05 12:00 |
10:36:00.84 |
+49:17:16.6 |
HIP 51750 |
19.59 |
| 2026-10-06 00:00 |
10:36:20.57 |
+49:17:18.0 |
HIP 51750 |
22.36 |
| 2026-10-06 12:00 |
10:36:40.23 |
+49:17:20.3 |
HIP 52092 |
19.89 |
| 2026-10-07 00:00 |
10:36:59.81 |
+49:17:23.7 |
HIP 52092 |
16.83 |
| 2026-10-07 12:00 |
10:37:19.32 |
+49:17:28.0 |
HIP 52092 |
13.84 |
| 2026-10-08 00:00 |
10:37:38.74 |
+49:17:33.4 |
HIP 52092 |
10.98 |
| 2026-10-08 12:00 |
10:37:58.09 |
+49:17:39.8 |
HIP 52092 |
8.37 |
| 2026-10-09 00:00 |
10:38:17.36 |
+49:17:47.2 |
HIP 52092 |
6.31 |
| 2026-10-09 12:00 |
10:38:36.56 |
+49:17:55.6 |
HIP 52092 |
5.44 |
| 2026-10-10 00:00 |
10:38:55.67 |
+49:18:05.0 |
HIP 52092 |
6.26 |
| 2026-10-10 12:00 |
10:39:14.70 |
+49:18:15.5 |
HIP 52092 |
8.26 |
| 2026-10-11 00:00 |
10:39:33.65 |
+49:18:27.0 |
HIP 52092 |
10.80 |