| 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) |
| 2026-05-12 00:00 |
21:12:57.73 |
-03:14:11.0 |
HIP 104622 |
21.45 |
| 2026-05-12 12:00 |
21:12:57.50 |
-03:13:59.3 |
HIP 104622 |
21.33 |
| 2026-05-13 00:00 |
21:12:57.24 |
-03:13:47.8 |
HIP 104622 |
21.21 |
| 2026-05-13 12:00 |
21:12:56.96 |
-03:13:36.3 |
HIP 104622 |
21.08 |
| 2026-05-14 00:00 |
21:12:56.65 |
-03:13:25.0 |
HIP 104622 |
20.95 |
| 2026-05-14 12:00 |
21:12:56.31 |
-03:13:13.8 |
HIP 104622 |
20.82 |
| 2026-05-15 00:00 |
21:12:55.95 |
-03:13:02.8 |
HIP 104622 |
20.68 |
| 2026-05-15 12:00 |
21:12:55.55 |
-03:12:51.8 |
HIP 104622 |
20.53 |
| 2026-05-16 00:00 |
21:12:55.14 |
-03:12:41.0 |
HIP 104622 |
20.39 |
| 2026-05-16 12:00 |
21:12:54.69 |
-03:12:30.4 |
HIP 104622 |
20.23 |
| 2026-05-17 00:00 |
21:12:54.22 |
-03:12:19.8 |
HIP 104622 |
20.07 |
| 2026-05-17 12:00 |
21:12:53.72 |
-03:12:09.4 |
HIP 104622 |
19.91 |
| 2026-05-18 00:00 |
21:12:53.20 |
-03:11:59.1 |
HIP 104622 |
19.74 |
| 2026-05-18 12:00 |
21:12:52.65 |
-03:11:49.0 |
HIP 104622 |
19.57 |
| 2026-05-19 00:00 |
21:12:52.07 |
-03:11:39.0 |
HIP 104622 |
19.39 |
| 2026-05-19 12:00 |
21:12:51.47 |
-03:11:29.1 |
HIP 104622 |
19.20 |
| 2026-05-20 00:00 |
21:12:50.84 |
-03:11:19.4 |
HIP 104622 |
19.01 |
| 2026-05-20 12:00 |
21:12:50.18 |
-03:11:09.8 |
HIP 104622 |
18.82 |
| 2026-05-21 00:00 |
21:12:49.50 |
-03:11:00.3 |
HIP 104622 |
18.62 |
| 2026-05-21 12:00 |
21:12:48.79 |
-03:10:51.0 |
HIP 104622 |
18.42 |
| 2026-05-22 00:00 |
21:12:48.06 |
-03:10:41.8 |
HIP 104622 |
18.21 |
| 2026-05-22 12:00 |
21:12:47.30 |
-03:10:32.8 |
HIP 104622 |
17.99 |
| 2026-05-23 00:00 |
21:12:46.51 |
-03:10:23.9 |
HIP 104622 |
17.77 |
| 2026-05-23 12:00 |
21:12:45.70 |
-03:10:15.1 |
HIP 104622 |
17.55 |
| 2026-05-24 00:00 |
21:12:44.87 |
-03:10:06.5 |
HIP 104622 |
17.32 |
| 2026-05-24 12:00 |
21:12:44.00 |
-03:09:58.0 |
HIP 104622 |
17.08 |
| 2026-05-25 00:00 |
21:12:43.11 |
-03:09:49.6 |
HIP 104622 |
16.84 |
| 2026-05-25 12:00 |
21:12:42.20 |
-03:09:41.4 |
HIP 104622 |
16.59 |
| 2026-05-26 00:00 |
21:12:41.26 |
-03:09:33.4 |
HIP 104622 |
16.34 |
| 2026-05-26 12:00 |
21:12:40.29 |
-03:09:25.4 |
HIP 104622 |
16.08 |
| 2026-05-27 00:00 |
21:12:39.30 |
-03:09:17.6 |
HIP 104622 |
15.82 |
| 2026-05-27 12:00 |
21:12:38.29 |
-03:09:10.0 |
HIP 104622 |
15.55 |
| 2026-05-28 00:00 |
21:12:37.24 |
-03:09:02.5 |
HIP 104622 |
15.28 |
| 2026-05-28 12:00 |
21:12:36.18 |
-03:08:55.1 |
HIP 104622 |
15.00 |
| 2026-05-29 00:00 |
21:12:35.09 |
-03:08:47.9 |
HIP 104622 |
14.72 |
| 2026-05-29 12:00 |
21:12:33.97 |
-03:08:40.8 |
HIP 104622 |
14.43 |
| 2026-05-30 00:00 |
21:12:32.83 |
-03:08:33.9 |
HIP 104622 |
14.13 |
| 2026-05-30 12:00 |
21:12:31.66 |
-03:08:27.1 |
HIP 104622 |
13.83 |
| 2026-05-31 00:00 |
21:12:30.47 |
-03:08:20.5 |
HIP 104622 |
13.53 |
| 2026-05-31 12:00 |
21:12:29.26 |
-03:08:14.0 |
HIP 104622 |
13.22 |
| 2026-06-01 00:00 |
21:12:28.02 |
-03:08:07.6 |
HIP 104622 |
12.90 |
| 2026-06-01 12:00 |
21:12:26.75 |
-03:08:01.4 |
HIP 104622 |
12.58 |
| 2026-06-02 00:00 |
21:12:25.46 |
-03:07:55.4 |
HIP 104622 |
12.25 |