C/2010 X1 (Elenin)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2010 X1 (Elenin) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2011-09-10T17:16:26.166720Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:31:47Z |
| Obs used | 2235 |
| NEO | - |
| M1 | 12.600 |
| K1 | 6.250 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2011-03-31.0000000 |
| e | 1.00006725 |
| q (au) | 0.482421 |
| a (au) | -7173.388485 |
| i (deg) | 1.839568 |
| Ω (om, deg) | 323.235147 |
| ω (w, deg) | 343.798118 |
| M (ma, deg) | -0.000266 |
Magnitude
Scatter + Global Linear
$$ M_a = (12.212 + 2.745\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 12.212 |
| n | 2.745 |
| gf | 0.800 |
| gb | -0.772 |
| k | 0.993 |
| 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 |
|---|---|---|---|
| 2010-12-10 | 2011-07-01 | +1.4907 | -0.743 |
| 2011-07-01 | 2011-08-03 | +16.9717 | -4.126 |
| 2011-08-03 | 2011-09-07 | -9.5074 | -4.344 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 07:32:56.94 | +22:38:05.1 | HIP 36708 | 4.89 |
| 2026-05-12 12:00 | 07:32:58.87 | +22:38:00.1 | HIP 36708 | 4.71 |
| 2026-05-13 00:00 | 07:33:00.82 | +22:37:55.1 | HIP 36708 | 4.56 |
| 2026-05-13 12:00 | 07:33:02.80 | +22:37:49.9 | HIP 36708 | 4.46 |
| 2026-05-14 00:00 | 07:33:04.80 | +22:37:44.8 | HIP 36708 | 4.41 |
| 2026-05-14 12:00 | 07:33:06.83 | +22:37:39.6 | HIP 36708 | 4.40 |
| 2026-05-15 00:00 | 07:33:08.88 | +22:37:34.3 | HIP 36708 | 4.45 |
| 2026-05-15 12:00 | 07:33:10.96 | +22:37:29.0 | HIP 36708 | 4.55 |
| 2026-05-16 00:00 | 07:33:13.07 | +22:37:23.6 | HIP 36708 | 4.70 |
| 2026-05-16 12:00 | 07:33:15.20 | +22:37:18.1 | HIP 36708 | 4.90 |
| 2026-05-17 00:00 | 07:33:17.35 | +22:37:12.7 | HIP 36708 | 5.14 |
| 2026-05-17 12:00 | 07:33:19.53 | +22:37:07.1 | HIP 36708 | 5.42 |
| 2026-05-18 00:00 | 07:33:21.74 | +22:37:01.5 | HIP 36708 | 5.74 |
| 2026-05-18 12:00 | 07:33:23.97 | +22:36:55.9 | HIP 36708 | 6.09 |
| 2026-05-19 00:00 | 07:33:26.22 | +22:36:50.2 | HIP 36708 | 6.47 |
| 2026-05-19 12:00 | 07:33:28.50 | +22:36:44.4 | HIP 36708 | 6.87 |
| 2026-05-20 00:00 | 07:33:30.81 | +22:36:38.6 | HIP 36708 | 7.30 |
| 2026-05-20 12:00 | 07:33:33.13 | +22:36:32.8 | HIP 36708 | 7.74 |
| 2026-05-21 00:00 | 07:33:35.48 | +22:36:26.9 | HIP 36708 | 8.20 |
| 2026-05-21 12:00 | 07:33:37.85 | +22:36:20.9 | HIP 36708 | 8.67 |
| 2026-05-22 00:00 | 07:33:40.25 | +22:36:14.9 | HIP 36708 | 9.16 |
| 2026-05-22 12:00 | 07:33:42.67 | +22:36:08.9 | HIP 36708 | 9.67 |
| 2026-05-23 00:00 | 07:33:45.11 | +22:36:02.8 | HIP 36708 | 10.18 |
| 2026-05-23 12:00 | 07:33:47.58 | +22:35:56.7 | HIP 36708 | 10.71 |
| 2026-05-24 00:00 | 07:33:50.06 | +22:35:50.5 | HIP 36708 | 11.24 |
| 2026-05-24 12:00 | 07:33:52.57 | +22:35:44.2 | HIP 36708 | 11.79 |
| 2026-05-25 00:00 | 07:33:55.10 | +22:35:38.0 | HIP 36708 | 12.34 |
| 2026-05-25 12:00 | 07:33:57.65 | +22:35:31.6 | HIP 36708 | 12.90 |
| 2026-05-26 00:00 | 07:34:00.23 | +22:35:25.3 | HIP 36708 | 13.47 |
| 2026-05-26 12:00 | 07:34:02.82 | +22:35:18.8 | HIP 36708 | 14.05 |
| 2026-05-27 00:00 | 07:34:05.44 | +22:35:12.4 | HIP 36708 | 14.63 |
| 2026-05-27 12:00 | 07:34:08.08 | +22:35:05.9 | HIP 36708 | 15.22 |
| 2026-05-28 00:00 | 07:34:10.74 | +22:34:59.3 | HIP 36708 | 15.82 |
| 2026-05-28 12:00 | 07:34:13.42 | +22:34:52.7 | HIP 36853 | 15.76 |
| 2026-05-29 00:00 | 07:34:16.12 | +22:34:46.1 | HIP 36853 | 15.43 |
| 2026-05-29 12:00 | 07:34:18.84 | +22:34:39.4 | HIP 36853 | 15.12 |
| 2026-05-30 00:00 | 07:34:21.58 | +22:34:32.7 | HIP 36853 | 14.83 |
| 2026-05-30 12:00 | 07:34:24.33 | +22:34:25.9 | HIP 36853 | 14.56 |
| 2026-05-31 00:00 | 07:34:27.11 | +22:34:19.1 | HIP 36853 | 14.31 |
| 2026-05-31 12:00 | 07:34:29.91 | +22:34:12.3 | HIP 36853 | 14.09 |
| 2026-06-01 00:00 | 07:34:32.73 | +22:34:05.4 | HIP 36853 | 13.89 |
| 2026-06-01 12:00 | 07:34:35.57 | +22:33:58.4 | HIP 36853 | 13.72 |
| 2026-06-02 00:00 | 07:34:38.43 | +22:33:51.5 | HIP 36853 | 13.59 |