C/2002 T7 (LINEAR)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2002 T7 (LINEAR) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2004-04-23T01:29:19.495680Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:30:22Z |
| Obs used | 4397 |
| NEO | - |
| M1 | 7.600 |
| K1 | 6.500 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2003-11-16.0000000 |
| e | 1.00048628 |
| q (au) | 0.614546 |
| a (au) | -1263.766985 |
| i (deg) | 160.582715 |
| Ω (om, deg) | 94.856573 |
| ω (w, deg) | 157.739084 |
| M (ma, deg) | -0.003490 |
Magnitude
Scatter + Global Linear
$$ M_a = (6.176 + 3.575\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 6.176 |
| n | 3.575 |
| 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 |
|---|---|---|---|
| 2001-01-14 | 2002-10-29 | -50.9308 | +42.214 |
| 2002-10-29 | 2004-04-22 | +0.0934 | -0.200 |
| 2004-04-23 | 2004-05-22 | +11.1569 | +2.707 |
| 2004-05-22 | 2006-03-20 | -0.3710 | +1.312 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-06-01 00:00 | 08:30:39.34 | +07:31:58.6 | HIP 41786 | 32.64 |
| 2026-06-01 12:00 | 08:30:40.75 | +07:32:00.2 | HIP 41786 | 32.58 |
| 2026-06-02 00:00 | 08:30:42.18 | +07:32:01.6 | HIP 41786 | 32.52 |
| 2026-06-02 12:00 | 08:30:43.63 | +07:32:03.0 | HIP 41786 | 32.46 |
| 2026-06-03 00:00 | 08:30:45.09 | +07:32:04.2 | HIP 41786 | 32.40 |
| 2026-06-03 12:00 | 08:30:46.58 | +07:32:05.3 | HIP 41786 | 32.35 |
| 2026-06-04 00:00 | 08:30:48.07 | +07:32:06.3 | HIP 41786 | 32.29 |
| 2026-06-04 12:00 | 08:30:49.59 | +07:32:07.3 | HIP 41786 | 32.24 |
| 2026-06-05 00:00 | 08:30:51.12 | +07:32:08.1 | HIP 41786 | 32.19 |
| 2026-06-05 12:00 | 08:30:52.67 | +07:32:08.8 | HIP 41786 | 32.14 |
| 2026-06-06 00:00 | 08:30:54.23 | +07:32:09.4 | HIP 41786 | 32.09 |
| 2026-06-06 12:00 | 08:30:55.81 | +07:32:09.9 | HIP 41786 | 32.05 |
| 2026-06-07 00:00 | 08:30:57.41 | +07:32:10.3 | HIP 41786 | 32.01 |
| 2026-06-07 12:00 | 08:30:59.02 | +07:32:10.6 | HIP 41786 | 31.97 |
| 2026-06-08 00:00 | 08:31:00.65 | +07:32:10.8 | HIP 41786 | 31.93 |
| 2026-06-08 12:00 | 08:31:02.29 | +07:32:10.9 | HIP 41786 | 31.90 |
| 2026-06-09 00:00 | 08:31:03.95 | +07:32:10.9 | HIP 41786 | 31.87 |
| 2026-06-09 12:00 | 08:31:05.62 | +07:32:10.8 | HIP 41786 | 31.84 |
| 2026-06-10 00:00 | 08:31:07.31 | +07:32:10.6 | HIP 41786 | 31.82 |
| 2026-06-10 12:00 | 08:31:09.02 | +07:32:10.2 | HIP 41786 | 31.80 |
| 2026-06-11 00:00 | 08:31:10.74 | +07:32:09.8 | HIP 41786 | 31.78 |
| 2026-06-11 12:00 | 08:31:12.47 | +07:32:09.3 | HIP 41786 | 31.77 |
| 2026-06-12 00:00 | 08:31:14.22 | +07:32:08.7 | HIP 41786 | 31.76 |
| 2026-06-12 12:00 | 08:31:15.99 | +07:32:07.9 | HIP 41786 | 31.76 |
| 2026-06-13 00:00 | 08:31:17.77 | +07:32:07.1 | HIP 41786 | 31.76 |
| 2026-06-13 12:00 | 08:31:19.56 | +07:32:06.1 | HIP 41786 | 31.77 |
| 2026-06-14 00:00 | 08:31:21.37 | +07:32:05.1 | HIP 41786 | 31.78 |
| 2026-06-14 12:00 | 08:31:23.20 | +07:32:03.9 | HIP 41786 | 31.80 |
| 2026-06-15 00:00 | 08:31:25.03 | +07:32:02.7 | HIP 41786 | 31.82 |
| 2026-06-15 12:00 | 08:31:26.88 | +07:32:01.3 | HIP 41786 | 31.84 |
| 2026-06-16 00:00 | 08:31:28.75 | +07:31:59.9 | HIP 41786 | 31.87 |
| 2026-06-16 12:00 | 08:31:30.63 | +07:31:58.3 | HIP 41786 | 31.91 |
| 2026-06-17 00:00 | 08:31:32.52 | +07:31:56.7 | HIP 41786 | 31.95 |
| 2026-06-17 12:00 | 08:31:34.42 | +07:31:54.9 | HIP 41786 | 32.00 |
| 2026-06-18 00:00 | 08:31:36.34 | +07:31:53.0 | HIP 42000 | 31.77 |
| 2026-06-18 12:00 | 08:31:38.27 | +07:31:51.1 | HIP 42000 | 31.33 |
| 2026-06-19 00:00 | 08:31:40.22 | +07:31:49.0 | HIP 42000 | 30.88 |
| 2026-06-19 12:00 | 08:31:42.17 | +07:31:46.9 | HIP 42000 | 30.44 |
| 2026-06-20 00:00 | 08:31:44.14 | +07:31:44.6 | HIP 42000 | 29.99 |
| 2026-06-20 12:00 | 08:31:46.12 | +07:31:42.2 | HIP 42000 | 29.54 |
| 2026-06-21 00:00 | 08:31:48.12 | +07:31:39.8 | HIP 42000 | 29.09 |
| 2026-06-21 12:00 | 08:31:50.12 | +07:31:37.2 | HIP 42000 | 28.64 |
| 2026-06-22 00:00 | 08:31:52.14 | +07:31:34.5 | HIP 42000 | 28.19 |