C/1984 N1 (Austin)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/1984 N1 (Austin) |
| Type | C |
| Perihelion (tp_cal, UTC) | 1984-08-12T03:17:25.103040Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:29:31Z |
| Obs used | 100 |
| NEO | - |
| M1 | 10.800 |
| K1 | 15.750 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 1984-09-13.0000000 |
| e | 0.99984838 |
| q (au) | 0.291283 |
| a (au) | 1921.159758 |
| i (deg) | 164.153161 |
| Ω (om, deg) | 171.577849 |
| ω (w, deg) | 353.128957 |
| M (ma, deg) | 0.000373 |
Magnitude
Scatter + Global Linear
$$ M_a = (7.757 + 2.984\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 7.757 |
| n | 2.984 |
| gf | 0.800 |
| gb | -0.500 |
| k | 0.800 |
| 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 |
|---|---|---|---|
| 1984-07-08 | 1984-07-30 | +8.5056 | +3.072 |
| 1984-07-30 | 1984-08-07 | -0.7727 | +0.324 |
| 1984-08-25 | 1984-09-14 | -0.8600 | -0.569 |
| 1984-09-14 | 1984-11-08 | +5.6851 | -0.575 |
| 1984-11-08 | 1984-11-28 | -2.4584 | +1.874 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 00:11:03.49 | +05:22:50.6 | HIP 898 | 10.32 |
| 2026-02-03 12:00 | 00:11:04.55 | +05:22:55.8 | HIP 898 | 10.41 |
| 2026-02-04 00:00 | 00:11:05.62 | +05:23:01.2 | HIP 898 | 10.50 |
| 2026-02-04 12:00 | 00:11:06.70 | +05:23:06.6 | HIP 898 | 10.60 |
| 2026-02-05 00:00 | 00:11:07.79 | +05:23:12.1 | HIP 898 | 10.71 |
| 2026-02-05 12:00 | 00:11:08.90 | +05:23:17.6 | HIP 898 | 10.83 |
| 2026-02-06 00:00 | 00:11:10.01 | +05:23:23.3 | HIP 898 | 10.95 |
| 2026-02-06 12:00 | 00:11:11.13 | +05:23:29.0 | HIP 898 | 11.09 |
| 2026-02-07 00:00 | 00:11:12.26 | +05:23:34.8 | HIP 898 | 11.23 |
| 2026-02-07 12:00 | 00:11:13.40 | +05:23:40.7 | HIP 898 | 11.38 |
| 2026-02-08 00:00 | 00:11:14.55 | +05:23:46.7 | HIP 898 | 11.53 |
| 2026-02-08 12:00 | 00:11:15.72 | +05:23:52.7 | HIP 898 | 11.70 |
| 2026-02-09 00:00 | 00:11:16.89 | +05:23:58.8 | HIP 898 | 11.87 |
| 2026-02-09 12:00 | 00:11:18.07 | +05:24:05.0 | HIP 898 | 12.05 |
| 2026-02-10 00:00 | 00:11:19.26 | +05:24:11.2 | HIP 898 | 12.23 |
| 2026-02-10 12:00 | 00:11:20.46 | +05:24:17.6 | HIP 898 | 12.43 |
| 2026-02-11 00:00 | 00:11:21.67 | +05:24:24.0 | HIP 898 | 12.63 |
| 2026-02-11 12:00 | 00:11:22.89 | +05:24:30.5 | HIP 898 | 12.83 |
| 2026-02-12 00:00 | 00:11:24.11 | +05:24:37.0 | HIP 898 | 13.05 |
| 2026-02-12 12:00 | 00:11:25.35 | +05:24:43.6 | HIP 898 | 13.26 |
| 2026-02-13 00:00 | 00:11:26.60 | +05:24:50.3 | HIP 898 | 13.49 |
| 2026-02-13 12:00 | 00:11:27.85 | +05:24:57.1 | HIP 898 | 13.72 |
| 2026-02-14 00:00 | 00:11:29.11 | +05:25:03.9 | HIP 898 | 13.96 |
| 2026-02-14 12:00 | 00:11:30.39 | +05:25:10.8 | HIP 898 | 14.21 |
| 2026-02-15 00:00 | 00:11:31.67 | +05:25:17.8 | HIP 898 | 14.46 |
| 2026-02-15 12:00 | 00:11:32.95 | +05:25:24.8 | HIP 898 | 14.71 |
| 2026-02-16 00:00 | 00:11:34.25 | +05:25:31.9 | HIP 898 | 14.97 |
| 2026-02-16 12:00 | 00:11:35.56 | +05:25:39.1 | HIP 898 | 15.24 |
| 2026-02-17 00:00 | 00:11:36.87 | +05:25:46.3 | HIP 898 | 15.51 |
| 2026-02-17 12:00 | 00:11:38.19 | +05:25:53.6 | HIP 898 | 15.79 |
| 2026-02-18 00:00 | 00:11:39.52 | +05:26:01.0 | HIP 898 | 16.07 |
| 2026-02-18 12:00 | 00:11:40.86 | +05:26:08.4 | HIP 898 | 16.35 |
| 2026-02-19 00:00 | 00:11:42.21 | +05:26:15.9 | HIP 898 | 16.65 |
| 2026-02-19 12:00 | 00:11:43.56 | +05:26:23.5 | HIP 898 | 16.94 |
| 2026-02-20 00:00 | 00:11:44.92 | +05:26:31.1 | HIP 898 | 17.24 |
| 2026-02-20 12:00 | 00:11:46.29 | +05:26:38.8 | HIP 898 | 17.54 |
| 2026-02-21 00:00 | 00:11:47.66 | +05:26:46.6 | HIP 898 | 17.85 |
| 2026-02-21 12:00 | 00:11:49.04 | +05:26:54.4 | HIP 898 | 18.16 |
| 2026-02-22 00:00 | 00:11:50.43 | +05:27:02.2 | HIP 898 | 18.48 |
| 2026-02-22 12:00 | 00:11:51.83 | +05:27:10.2 | HIP 898 | 18.80 |
| 2026-02-23 00:00 | 00:11:53.23 | +05:27:18.1 | HIP 898 | 19.12 |
| 2026-02-23 12:00 | 00:11:54.64 | +05:27:26.2 | HIP 898 | 19.45 |
| 2026-02-24 00:00 | 00:11:56.05 | +05:27:34.3 | HIP 898 | 19.78 |