P/2011 N1 (ASH)
Metadata
| Parameter | Value |
|---|---|
| Designation | P/2011 N1 (ASH) |
| Type | P |
| Perihelion (tp_cal, UTC) | 2012-05-31T06:52:34.999680Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:31:52Z |
| Obs used | 269 |
| NEO | - |
| M1 | 12.800 |
| K1 | 5.250 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2011-12-30.0000000 |
| e | 0.54594610 |
| q (au) | 2.857717 |
| a (au) | 6.293785 |
| i (deg) | 35.668884 |
| Ω (om, deg) | 77.690510 |
| ω (w, deg) | 331.056188 |
| M (ma, deg) | 350.431581 |
Magnitude
Scatter + Global Linear
$$ M_a = (12.378 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 12.378 |
| n | 2.000 |
| gf | 0.999 |
| gb | -0.500 |
| 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 |
|---|---|---|---|
| 2011-07-01 | 2012-02-01 | +4.8034 | -2.824 |
| 2012-09-29 | 2014-03-21 | -1.2040 | +2.406 |
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 | 21:11:24.08 | -54:53:40.9 | HIP 104497 | 14.49 |
| 2026-09-20 12:00 | 21:11:09.84 | -54:52:18.1 | HIP 104497 | 12.03 |
| 2026-09-21 00:00 | 21:10:55.94 | -54:50:52.9 | HIP 104497 | 9.58 |
| 2026-09-21 12:00 | 21:10:42.37 | -54:49:25.2 | HIP 104497 | 7.14 |
| 2026-09-22 00:00 | 21:10:29.14 | -54:47:55.2 | HIP 104497 | 4.72 |
| 2026-09-22 12:00 | 21:10:16.25 | -54:46:22.8 | HIP 104497 | 2.30 |
| 2026-09-23 00:00 | 21:10:03.71 | -54:44:48.0 | HIP 104497 | 0.11 |
| 2026-09-23 12:00 | 21:09:51.51 | -54:43:11.0 | HIP 104497 | 2.49 |
| 2026-09-24 00:00 | 21:09:39.66 | -54:41:31.7 | HIP 104497 | 4.87 |
| 2026-09-24 12:00 | 21:09:28.16 | -54:39:50.0 | HIP 104497 | 7.24 |
| 2026-09-25 00:00 | 21:09:17.01 | -54:38:06.2 | HIP 104497 | 9.60 |
| 2026-09-25 12:00 | 21:09:06.21 | -54:36:20.1 | HIP 104526 | 11.61 |
| 2026-09-26 00:00 | 21:08:55.76 | -54:34:31.8 | HIP 104322 | 12.91 |
| 2026-09-26 12:00 | 21:08:45.67 | -54:32:41.4 | HIP 104322 | 13.58 |
| 2026-09-27 00:00 | 21:08:35.93 | -54:30:48.8 | HIP 104322 | 14.66 |
| 2026-09-27 12:00 | 21:08:26.56 | -54:28:54.1 | HIP 104322 | 16.06 |
| 2026-09-28 00:00 | 21:08:17.54 | -54:26:57.2 | HIP 104308 | 14.49 |
| 2026-09-28 12:00 | 21:08:08.88 | -54:24:58.3 | HIP 104308 | 12.27 |
| 2026-09-29 00:00 | 21:08:00.58 | -54:22:57.3 | HIP 104308 | 10.07 |
| 2026-09-29 12:00 | 21:07:52.64 | -54:20:54.3 | HIP 104308 | 7.93 |
| 2026-09-30 00:00 | 21:07:45.07 | -54:18:49.3 | HIP 104308 | 5.91 |
| 2026-09-30 12:00 | 21:07:37.86 | -54:16:42.2 | HIP 104308 | 4.20 |
| 2026-10-01 00:00 | 21:07:31.01 | -54:14:33.2 | HIP 104308 | 3.34 |
| 2026-10-01 12:00 | 21:07:24.53 | -54:12:22.2 | HIP 104308 | 3.94 |
| 2026-10-02 00:00 | 21:07:18.42 | -54:10:09.3 | HIP 104308 | 5.56 |
| 2026-10-02 12:00 | 21:07:12.68 | -54:07:54.5 | HIP 104308 | 7.58 |
| 2026-10-03 00:00 | 21:07:07.30 | -54:05:37.8 | HIP 104308 | 9.76 |
| 2026-10-03 12:00 | 21:07:02.29 | -54:03:19.2 | HIP 104308 | 12.03 |
| 2026-10-04 00:00 | 21:06:57.65 | -54:00:58.7 | HIP 104308 | 14.34 |
| 2026-10-04 12:00 | 21:06:53.38 | -53:58:36.4 | HIP 104308 | 16.69 |
| 2026-10-05 00:00 | 21:06:49.48 | -53:56:12.3 | HIP 104308 | 19.06 |
| 2026-10-05 12:00 | 21:06:45.96 | -53:53:46.4 | HIP 104308 | 21.46 |
| 2026-10-06 00:00 | 21:06:42.80 | -53:51:18.7 | HIP 104308 | 23.88 |
| 2026-10-06 12:00 | 21:06:40.02 | -53:48:49.3 | HIP 104308 | 26.32 |
| 2026-10-07 00:00 | 21:06:37.61 | -53:46:18.2 | HIP 104308 | 28.79 |
| 2026-10-07 12:00 | 21:06:35.57 | -53:43:45.3 | HIP 104308 | 31.27 |
| 2026-10-08 00:00 | 21:06:33.90 | -53:41:10.8 | HIP 104359 | 30.43 |
| 2026-10-08 12:00 | 21:06:32.60 | -53:38:34.6 | HIP 104359 | 28.43 |
| 2026-10-09 00:00 | 21:06:31.68 | -53:35:56.7 | HIP 104359 | 26.49 |
| 2026-10-09 12:00 | 21:06:31.13 | -53:33:17.2 | HIP 104359 | 24.62 |
| 2026-10-10 00:00 | 21:06:30.95 | -53:30:36.2 | HIP 104359 | 22.84 |
| 2026-10-10 12:00 | 21:06:31.15 | -53:27:53.5 | HIP 104359 | 21.19 |
| 2026-10-11 00:00 | 21:06:31.71 | -53:25:09.3 | HIP 104359 | 19.72 |