C/2012 T4 (McNaught)
| Parameter |
Value |
| Designation |
C/2012 T4 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2012-10-10T22:22:44.699520Z |
| Orbit solution date (soln_date, UTC) |
2022-06-07T21:44:03Z |
| Obs used |
49 |
| NEO |
- |
| M1 |
15.500 |
| K1 |
6.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-10-18.0000000 |
| e |
0.99118923 |
| q (au) |
1.955997 |
| a (au) |
222.000586 |
| i (deg) |
24.085273 |
| Ω (om, deg) |
99.368559 |
| ω (w, deg) |
219.915260 |
| M (ma, deg) |
0.002106 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.048 + 4.167\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.048 |
| n |
4.167 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.990 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
07:23:14.79 |
+26:42:48.3 |
HIP 35967 |
21.58 |
| 2026-02-03 12:00 |
07:23:10.84 |
+26:42:55.4 |
HIP 35967 |
22.47 |
| 2026-02-04 00:00 |
07:23:06.91 |
+26:43:02.4 |
HIP 35967 |
23.35 |
| 2026-02-04 12:00 |
07:23:03.01 |
+26:43:09.3 |
HIP 35967 |
24.22 |
| 2026-02-05 00:00 |
07:22:59.12 |
+26:43:16.1 |
HIP 35967 |
25.09 |
| 2026-02-05 12:00 |
07:22:55.25 |
+26:43:22.9 |
HIP 35967 |
25.96 |
| 2026-02-06 00:00 |
07:22:51.40 |
+26:43:29.5 |
HIP 35639 |
25.49 |
| 2026-02-06 12:00 |
07:22:47.57 |
+26:43:36.1 |
HIP 35639 |
24.84 |
| 2026-02-07 00:00 |
07:22:43.76 |
+26:43:42.6 |
HIP 35639 |
24.20 |
| 2026-02-07 12:00 |
07:22:39.98 |
+26:43:49.0 |
HIP 35639 |
23.58 |
| 2026-02-08 00:00 |
07:22:36.21 |
+26:43:55.3 |
HIP 35639 |
22.98 |
| 2026-02-08 12:00 |
07:22:32.47 |
+26:44:01.5 |
HIP 35639 |
22.39 |
| 2026-02-09 00:00 |
07:22:28.74 |
+26:44:07.7 |
HIP 35639 |
21.83 |
| 2026-02-09 12:00 |
07:22:25.04 |
+26:44:13.7 |
HIP 35639 |
21.29 |
| 2026-02-10 00:00 |
07:22:21.37 |
+26:44:19.7 |
HIP 35639 |
20.76 |
| 2026-02-10 12:00 |
07:22:17.71 |
+26:44:25.6 |
HIP 35639 |
20.27 |
| 2026-02-11 00:00 |
07:22:14.08 |
+26:44:31.4 |
HIP 35639 |
19.79 |
| 2026-02-11 12:00 |
07:22:10.47 |
+26:44:37.1 |
HIP 35639 |
19.34 |
| 2026-02-12 00:00 |
07:22:06.89 |
+26:44:42.7 |
HIP 35639 |
18.92 |
| 2026-02-12 12:00 |
07:22:03.33 |
+26:44:48.2 |
HIP 35639 |
18.52 |
| 2026-02-13 00:00 |
07:21:59.79 |
+26:44:53.7 |
HIP 35639 |
18.15 |
| 2026-02-13 12:00 |
07:21:56.28 |
+26:44:59.0 |
HIP 35639 |
17.82 |
| 2026-02-14 00:00 |
07:21:52.80 |
+26:45:04.3 |
HIP 35639 |
17.51 |
| 2026-02-14 12:00 |
07:21:49.34 |
+26:45:09.5 |
HIP 35639 |
17.23 |
| 2026-02-15 00:00 |
07:21:45.91 |
+26:45:14.6 |
HIP 35639 |
16.99 |
| 2026-02-15 12:00 |
07:21:42.50 |
+26:45:19.6 |
HIP 35639 |
16.78 |
| 2026-02-16 00:00 |
07:21:39.12 |
+26:45:24.5 |
HIP 35639 |
16.60 |
| 2026-02-16 12:00 |
07:21:35.76 |
+26:45:29.3 |
HIP 35639 |
16.45 |
| 2026-02-17 00:00 |
07:21:32.44 |
+26:45:34.1 |
HIP 35639 |
16.34 |
| 2026-02-17 12:00 |
07:21:29.14 |
+26:45:38.7 |
HIP 35639 |
16.26 |
| 2026-02-18 00:00 |
07:21:25.86 |
+26:45:43.3 |
HIP 35639 |
16.22 |
| 2026-02-18 12:00 |
07:21:22.62 |
+26:45:47.7 |
HIP 35639 |
16.21 |
| 2026-02-19 00:00 |
07:21:19.40 |
+26:45:52.1 |
HIP 35639 |
16.23 |
| 2026-02-19 12:00 |
07:21:16.22 |
+26:45:56.4 |
HIP 35639 |
16.27 |
| 2026-02-20 00:00 |
07:21:13.06 |
+26:46:00.6 |
HIP 35639 |
16.35 |
| 2026-02-20 12:00 |
07:21:09.93 |
+26:46:04.7 |
HIP 35639 |
16.46 |
| 2026-02-21 00:00 |
07:21:06.83 |
+26:46:08.7 |
HIP 35639 |
16.60 |
| 2026-02-21 12:00 |
07:21:03.76 |
+26:46:12.6 |
HIP 35639 |
16.75 |
| 2026-02-22 00:00 |
07:21:00.71 |
+26:46:16.5 |
HIP 35639 |
16.94 |
| 2026-02-22 12:00 |
07:20:57.70 |
+26:46:20.2 |
HIP 35639 |
17.14 |
| 2026-02-23 00:00 |
07:20:54.72 |
+26:46:23.9 |
HIP 35639 |
17.37 |
| 2026-02-23 12:00 |
07:20:51.77 |
+26:46:27.4 |
HIP 35639 |
17.61 |
| 2026-02-24 00:00 |
07:20:48.85 |
+26:46:30.9 |
HIP 35494 |
17.65 |