210P/Christensen
Metadata
| Parameter | Value |
|---|---|
| Designation | 210P/Christensen |
| Type | P |
| Perihelion (tp_cal, UTC) | 2025-11-22T17:09:24.215040Z |
| Orbit solution date (soln_date, UTC) | 2026-09-08T08:47:29Z |
| Obs used | 262 |
| NEO | Yes |
| M1 | 14.200 |
| K1 | 15.000 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2024-09-30.0000000 |
| e | 0.83405299 |
| q (au) | 0.524671 |
| a (au) | 3.161679 |
| i (deg) | 10.286600 |
| Ω (om, deg) | 93.798006 |
| ω (w, deg) | 345.932905 |
| M (ma, deg) | 286.591586 |
Magnitude
Scatter + Global Linear
$$ M_a = (15.262 + 2.954\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 15.262 |
| n | 2.954 |
| gf | 0.800 |
| gb | -0.500 |
| k | 1.000 |
| δ90 | 1.000 |
| 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 |
|---|---|---|---|
| 2025-07-19 | 2025-11-04 | +5.8982 | +1.198 |
| 2025-11-26 | 2026-05-09 | +1.5482 | -1.408 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Finding Chart
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 14:40:17.26 | -09:26:31.6 | HIP 71788 | 12.25 |
| 2026-09-20 12:00 | 14:40:45.15 | -09:29:24.0 | HIP 71788 | 4.87 |
| 2026-09-21 00:00 | 14:41:13.09 | -09:32:16.0 | HIP 71788 | 2.91 |
| 2026-09-21 12:00 | 14:41:41.08 | -09:35:07.7 | HIP 71788 | 10.23 |
| 2026-09-22 00:00 | 14:42:09.12 | -09:37:58.9 | HIP 71834 | 12.60 |
| 2026-09-22 12:00 | 14:42:37.21 | -09:40:49.8 | HIP 71997 | 12.04 |
| 2026-09-23 00:00 | 14:43:05.35 | -09:43:40.4 | HIP 71997 | 5.32 |
| 2026-09-23 12:00 | 14:43:33.53 | -09:46:30.5 | HIP 71997 | 4.91 |
| 2026-09-24 00:00 | 14:44:01.77 | -09:49:20.3 | HIP 71997 | 11.51 |
| 2026-09-24 12:00 | 14:44:30.05 | -09:52:09.6 | HIP 72082 | 10.59 |
| 2026-09-25 00:00 | 14:44:58.38 | -09:54:58.6 | HIP 72082 | 13.16 |
| 2026-09-25 12:00 | 14:45:26.75 | -09:57:47.2 | HIP 72082 | 18.63 |
| 2026-09-26 00:00 | 14:45:55.17 | -10:00:35.5 | HIP 72283 | 15.25 |
| 2026-09-26 12:00 | 14:46:23.63 | -10:03:23.3 | HIP 72283 | 9.35 |
| 2026-09-27 00:00 | 14:46:52.13 | -10:06:10.7 | HIP 72283 | 7.49 |
| 2026-09-27 12:00 | 14:47:20.68 | -10:08:57.7 | HIP 72283 | 11.79 |
| 2026-09-28 00:00 | 14:47:49.28 | -10:11:44.4 | HIP 72283 | 18.33 |
| 2026-09-28 12:00 | 14:48:17.91 | -10:14:30.6 | HIP 72283 | 25.45 |
| 2026-09-29 00:00 | 14:48:46.59 | -10:17:16.4 | HIP 72283 | 32.78 |
| 2026-09-29 12:00 | 14:49:15.30 | -10:20:01.9 | HIP 72478 | 29.62 |
| 2026-09-30 00:00 | 14:49:44.06 | -10:22:46.9 | HIP 72668 | 27.56 |
| 2026-09-30 12:00 | 14:50:12.86 | -10:25:31.5 | HIP 72668 | 19.96 |
| 2026-10-01 00:00 | 14:50:41.70 | -10:28:15.6 | HIP 72668 | 12.36 |
| 2026-10-01 12:00 | 14:51:10.58 | -10:30:59.4 | HIP 72668 | 4.76 |
| 2026-10-02 00:00 | 14:51:39.49 | -10:33:42.8 | HIP 72668 | 2.87 |
| 2026-10-02 12:00 | 14:52:08.45 | -10:36:25.7 | HIP 72668 | 10.48 |
| 2026-10-03 00:00 | 14:52:37.44 | -10:39:08.2 | HIP 72668 | 18.10 |
| 2026-10-03 12:00 | 14:53:06.47 | -10:41:50.3 | HIP 72668 | 25.72 |
| 2026-10-04 00:00 | 14:53:35.54 | -10:44:32.0 | HIP 72758 | 32.35 |
| 2026-10-04 12:00 | 14:54:04.64 | -10:47:13.2 | HIP 72758 | 34.57 |
| 2026-10-05 00:00 | 14:54:33.78 | -10:49:54.0 | HIP 73031 | 35.89 |
| 2026-10-05 12:00 | 14:55:02.96 | -10:52:34.3 | HIP 73031 | 36.34 |
| 2026-10-06 00:00 | 14:55:32.16 | -10:55:14.3 | HIP 73133 | 34.50 |
| 2026-10-06 12:00 | 14:56:01.41 | -10:57:53.7 | HIP 73133 | 28.85 |
| 2026-10-07 00:00 | 14:56:30.68 | -11:00:32.8 | HIP 73133 | 24.33 |
| 2026-10-07 12:00 | 14:57:00.00 | -11:03:11.3 | HIP 73249 | 19.02 |
| 2026-10-08 00:00 | 14:57:29.33 | -11:05:49.5 | HIP 73249 | 11.35 |
| 2026-10-08 12:00 | 14:57:58.71 | -11:08:27.1 | HIP 73249 | 3.70 |
| 2026-10-09 00:00 | 14:58:28.11 | -11:11:04.3 | HIP 73249 | 4.02 |
| 2026-10-09 12:00 | 14:58:57.54 | -11:13:41.1 | HIP 73310 | 5.14 |
| 2026-10-10 00:00 | 14:59:27.00 | -11:16:17.4 | HIP 73310 | 11.21 |
| 2026-10-10 12:00 | 14:59:56.49 | -11:18:53.2 | HIP 73457 | 15.81 |
| 2026-10-11 00:00 | 15:00:26.01 | -11:21:28.5 | HIP 73457 | 14.10 |