| Parameter |
Value |
| Designation |
C/2008 T2 (Cardinal) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2009-06-13T05:44:59.979840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:24Z |
| Obs used |
1309 |
| NEO |
- |
| M1 |
11.200 |
| K1 |
5.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2009-02-08.0000000 |
| e |
1.00010902 |
| q (au) |
1.202208 |
| a (au) |
-11027.760878 |
| i (deg) |
56.303690 |
| Ω (om, deg) |
309.678521 |
| ω (w, deg) |
215.871148 |
| M (ma, deg) |
-0.000107 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.536 + 3.857\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.536 |
| n |
3.857 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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 |
| 2008-03-20 |
2008-10-08 |
-32.2881 |
+17.516 |
| 2008-10-08 |
2009-04-10 |
+1.8402 |
-0.993 |
| 2009-04-10 |
2009-06-12 |
+22.8692 |
-5.412 |
| 2009-06-13 |
2009-10-10 |
+3.9717 |
-3.676 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
21:02:48.15 |
-03:37:32.8 |
HIP 103729 |
27.19 |
| 2026-09-20 12:00 |
21:02:45.95 |
-03:37:48.5 |
HIP 103729 |
26.80 |
| 2026-09-21 00:00 |
21:02:43.76 |
-03:38:04.2 |
HIP 103729 |
26.42 |
| 2026-09-21 12:00 |
21:02:41.60 |
-03:38:19.9 |
HIP 103729 |
26.05 |
| 2026-09-22 00:00 |
21:02:39.46 |
-03:38:35.6 |
HIP 103729 |
25.70 |
| 2026-09-22 12:00 |
21:02:37.33 |
-03:38:51.2 |
HIP 103729 |
25.36 |
| 2026-09-23 00:00 |
21:02:35.23 |
-03:39:06.8 |
HIP 103729 |
25.03 |
| 2026-09-23 12:00 |
21:02:33.14 |
-03:39:22.4 |
HIP 103729 |
24.72 |
| 2026-09-24 00:00 |
21:02:31.08 |
-03:39:37.9 |
HIP 103729 |
24.42 |
| 2026-09-24 12:00 |
21:02:29.04 |
-03:39:53.4 |
HIP 103729 |
24.14 |
| 2026-09-25 00:00 |
21:02:27.02 |
-03:40:08.9 |
HIP 103729 |
23.87 |
| 2026-09-25 12:00 |
21:02:25.02 |
-03:40:24.4 |
HIP 103729 |
23.61 |
| 2026-09-26 00:00 |
21:02:23.04 |
-03:40:39.8 |
HIP 103729 |
23.37 |
| 2026-09-26 12:00 |
21:02:21.09 |
-03:40:55.2 |
HIP 103729 |
23.14 |
| 2026-09-27 00:00 |
21:02:19.15 |
-03:41:10.6 |
HIP 103729 |
22.93 |
| 2026-09-27 12:00 |
21:02:17.24 |
-03:41:25.9 |
HIP 103729 |
22.73 |
| 2026-09-28 00:00 |
21:02:15.35 |
-03:41:41.2 |
HIP 103729 |
22.55 |
| 2026-09-28 12:00 |
21:02:13.48 |
-03:41:56.4 |
HIP 103729 |
22.38 |
| 2026-09-29 00:00 |
21:02:11.63 |
-03:42:11.7 |
HIP 103729 |
22.23 |
| 2026-09-29 12:00 |
21:02:09.81 |
-03:42:26.8 |
HIP 103729 |
22.09 |
| 2026-09-30 00:00 |
21:02:08.01 |
-03:42:41.9 |
HIP 103729 |
21.97 |
| 2026-09-30 12:00 |
21:02:06.23 |
-03:42:57.0 |
HIP 103729 |
21.86 |
| 2026-10-01 00:00 |
21:02:04.47 |
-03:43:12.1 |
HIP 103729 |
21.77 |
| 2026-10-01 12:00 |
21:02:02.73 |
-03:43:27.1 |
HIP 103729 |
21.69 |
| 2026-10-02 00:00 |
21:02:01.02 |
-03:43:42.0 |
HIP 103729 |
21.62 |
| 2026-10-02 12:00 |
21:01:59.33 |
-03:43:56.9 |
HIP 103729 |
21.57 |
| 2026-10-03 00:00 |
21:01:57.67 |
-03:44:11.8 |
HIP 103729 |
21.54 |
| 2026-10-03 12:00 |
21:01:56.03 |
-03:44:26.6 |
HIP 103729 |
21.51 |
| 2026-10-04 00:00 |
21:01:54.41 |
-03:44:41.3 |
HIP 103729 |
21.50 |
| 2026-10-04 12:00 |
21:01:52.81 |
-03:44:56.0 |
HIP 103729 |
21.50 |
| 2026-10-05 00:00 |
21:01:51.24 |
-03:45:10.7 |
HIP 103729 |
21.51 |
| 2026-10-05 12:00 |
21:01:49.70 |
-03:45:25.3 |
HIP 103729 |
21.54 |
| 2026-10-06 00:00 |
21:01:48.18 |
-03:45:39.8 |
HIP 103729 |
21.58 |
| 2026-10-06 12:00 |
21:01:46.68 |
-03:45:54.2 |
HIP 103729 |
21.62 |
| 2026-10-07 00:00 |
21:01:45.20 |
-03:46:08.7 |
HIP 103729 |
21.68 |
| 2026-10-07 12:00 |
21:01:43.75 |
-03:46:23.0 |
HIP 103769 |
21.52 |
| 2026-10-08 00:00 |
21:01:42.33 |
-03:46:37.3 |
HIP 103769 |
21.27 |
| 2026-10-08 12:00 |
21:01:40.93 |
-03:46:51.5 |
HIP 103769 |
21.03 |
| 2026-10-09 00:00 |
21:01:39.55 |
-03:47:05.7 |
HIP 103769 |
20.80 |
| 2026-10-09 12:00 |
21:01:38.20 |
-03:47:19.8 |
HIP 103769 |
20.57 |
| 2026-10-10 00:00 |
21:01:36.88 |
-03:47:33.8 |
HIP 103769 |
20.35 |
| 2026-10-10 12:00 |
21:01:35.58 |
-03:47:47.7 |
HIP 103769 |
20.13 |
| 2026-10-11 00:00 |
21:01:34.30 |
-03:48:01.6 |
HIP 103769 |
19.92 |