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) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 07:41:14.50 | +22:18:07.7 | HIP 37476 | 12.02 |
| 2026-07-29 12:00 | 07:41:18.09 | +22:17:59.3 | HIP 37476 | 11.59 |
| 2026-07-30 00:00 | 07:41:21.67 | +22:17:50.8 | HIP 37476 | 11.21 |
| 2026-07-30 12:00 | 07:41:25.25 | +22:17:42.4 | HIP 37476 | 10.88 |
| 2026-07-31 00:00 | 07:41:28.82 | +22:17:34.0 | HIP 37476 | 10.61 |
| 2026-07-31 12:00 | 07:41:32.38 | +22:17:25.6 | HIP 37476 | 10.39 |
| 2026-08-01 00:00 | 07:41:35.94 | +22:17:17.2 | HIP 37476 | 10.24 |
| 2026-08-01 12:00 | 07:41:39.48 | +22:17:08.9 | HIP 37476 | 10.16 |
| 2026-08-02 00:00 | 07:41:43.02 | +22:17:00.6 | HIP 37476 | 10.15 |
| 2026-08-02 12:00 | 07:41:46.55 | +22:16:52.2 | HIP 37476 | 10.20 |
| 2026-08-03 00:00 | 07:41:50.08 | +22:16:44.0 | HIP 37476 | 10.32 |
| 2026-08-03 12:00 | 07:41:53.59 | +22:16:35.7 | HIP 37476 | 10.51 |
| 2026-08-04 00:00 | 07:41:57.10 | +22:16:27.5 | HIP 37476 | 10.75 |
| 2026-08-04 12:00 | 07:42:00.59 | +22:16:19.2 | HIP 37579 | 10.22 |
| 2026-08-05 00:00 | 07:42:04.08 | +22:16:11.0 | HIP 37579 | 9.41 |
| 2026-08-05 12:00 | 07:42:07.56 | +22:16:02.9 | HIP 37579 | 8.60 |
| 2026-08-06 00:00 | 07:42:11.03 | +22:15:54.7 | HIP 37579 | 7.80 |
| 2026-08-06 12:00 | 07:42:14.49 | +22:15:46.6 | HIP 37579 | 7.00 |
| 2026-08-07 00:00 | 07:42:17.93 | +22:15:38.5 | HIP 37579 | 6.20 |
| 2026-08-07 12:00 | 07:42:21.37 | +22:15:30.5 | HIP 37579 | 5.41 |
| 2026-08-08 00:00 | 07:42:24.80 | +22:15:22.4 | HIP 37579 | 4.63 |
| 2026-08-08 12:00 | 07:42:28.21 | +22:15:14.4 | HIP 37579 | 3.86 |
| 2026-08-09 00:00 | 07:42:31.62 | +22:15:06.4 | HIP 37579 | 3.11 |
| 2026-08-09 12:00 | 07:42:35.01 | +22:14:58.5 | HIP 37579 | 2.40 |
| 2026-08-10 00:00 | 07:42:38.39 | +22:14:50.5 | HIP 37579 | 1.76 |
| 2026-08-10 12:00 | 07:42:41.76 | +22:14:42.6 | HIP 37579 | 1.30 |
| 2026-08-11 00:00 | 07:42:45.12 | +22:14:34.8 | HIP 37579 | 1.23 |
| 2026-08-11 12:00 | 07:42:48.47 | +22:14:26.9 | HIP 37579 | 1.61 |
| 2026-08-12 00:00 | 07:42:51.80 | +22:14:19.1 | HIP 37579 | 2.22 |
| 2026-08-12 12:00 | 07:42:55.12 | +22:14:11.4 | HIP 37579 | 2.90 |
| 2026-08-13 00:00 | 07:42:58.43 | +22:14:03.6 | HIP 37579 | 3.62 |
| 2026-08-13 12:00 | 07:43:01.72 | +22:13:55.9 | HIP 37579 | 4.36 |
| 2026-08-14 00:00 | 07:43:05.01 | +22:13:48.3 | HIP 37579 | 5.11 |
| 2026-08-14 12:00 | 07:43:08.27 | +22:13:40.6 | HIP 37579 | 5.85 |
| 2026-08-15 00:00 | 07:43:11.53 | +22:13:33.0 | HIP 37579 | 6.60 |
| 2026-08-15 12:00 | 07:43:14.77 | +22:13:25.5 | HIP 37579 | 7.35 |
| 2026-08-16 00:00 | 07:43:17.99 | +22:13:18.0 | HIP 37579 | 8.10 |
| 2026-08-16 12:00 | 07:43:21.20 | +22:13:10.5 | HIP 37579 | 8.85 |
| 2026-08-17 00:00 | 07:43:24.40 | +22:13:03.0 | HIP 37579 | 9.59 |
| 2026-08-17 12:00 | 07:43:27.58 | +22:12:55.6 | HIP 37579 | 10.33 |
| 2026-08-18 00:00 | 07:43:30.74 | +22:12:48.3 | HIP 37579 | 11.07 |
| 2026-08-18 12:00 | 07:43:33.89 | +22:12:40.9 | HIP 37636 | 11.60 |
| 2026-08-19 00:00 | 07:43:37.03 | +22:12:33.6 | HIP 37636 | 11.91 |