| Parameter |
Value |
| Designation |
C/2005 E2 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2006-02-23T11:21:44.352000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:47Z |
| Obs used |
1317 |
| NEO |
- |
| M1 |
9.200 |
| K1 |
7.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2006-05-09.0000000 |
| e |
1.00013891 |
| q (au) |
1.519579 |
| a (au) |
-10939.545227 |
| i (deg) |
16.988338 |
| Ω (om, deg) |
347.847398 |
| ω (w, deg) |
39.966443 |
| M (ma, deg) |
0.000064 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.499 + 2.796\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.499 |
| n |
2.796 |
| gf |
0.997 |
| gb |
-0.504 |
| k |
1.000 |
| 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 |
| 2005-03-12 |
2006-02-23 |
-0.0277 |
-0.832 |
| 2006-02-23 |
2006-05-02 |
-34.1611 |
+5.629 |
| 2006-05-02 |
2006-10-31 |
+10.7800 |
-5.797 |
| 2006-10-31 |
2007-03-17 |
-2.8237 |
+2.023 |
| 2007-03-17 |
2008-03-02 |
+3.2324 |
-2.351 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
12:09:43.34 |
-06:45:00.1 |
HIP 59209 |
18.04 |
| 2026-03-26 12:00 |
12:09:40.67 |
-06:44:43.4 |
HIP 59209 |
17.52 |
| 2026-03-27 00:00 |
12:09:38.00 |
-06:44:26.7 |
HIP 59209 |
17.01 |
| 2026-03-27 12:00 |
12:09:35.34 |
-06:44:09.9 |
HIP 59209 |
16.53 |
| 2026-03-28 00:00 |
12:09:32.67 |
-06:43:53.1 |
HIP 59209 |
16.06 |
| 2026-03-28 12:00 |
12:09:30.01 |
-06:43:36.3 |
HIP 59209 |
15.61 |
| 2026-03-29 00:00 |
12:09:27.35 |
-06:43:19.5 |
HIP 59209 |
15.18 |
| 2026-03-29 12:00 |
12:09:24.69 |
-06:43:02.7 |
HIP 59209 |
14.78 |
| 2026-03-30 00:00 |
12:09:22.04 |
-06:42:45.8 |
HIP 59209 |
14.40 |
| 2026-03-30 12:00 |
12:09:19.38 |
-06:42:28.9 |
HIP 59209 |
14.05 |
| 2026-03-31 00:00 |
12:09:16.73 |
-06:42:12.0 |
HIP 59209 |
13.73 |
| 2026-03-31 12:00 |
12:09:14.09 |
-06:41:55.1 |
HIP 59209 |
13.44 |
| 2026-04-01 00:00 |
12:09:11.45 |
-06:41:38.2 |
HIP 59209 |
13.18 |
| 2026-04-01 12:00 |
12:09:08.81 |
-06:41:21.2 |
HIP 59209 |
12.96 |
| 2026-04-02 00:00 |
12:09:06.18 |
-06:41:04.2 |
HIP 59209 |
12.77 |
| 2026-04-02 12:00 |
12:09:03.55 |
-06:40:47.3 |
HIP 59209 |
12.62 |
| 2026-04-03 00:00 |
12:09:00.93 |
-06:40:30.3 |
HIP 59209 |
12.51 |
| 2026-04-03 12:00 |
12:08:58.31 |
-06:40:13.3 |
HIP 59209 |
12.44 |
| 2026-04-04 00:00 |
12:08:55.69 |
-06:39:56.3 |
HIP 59209 |
12.42 |
| 2026-04-04 12:00 |
12:08:53.08 |
-06:39:39.3 |
HIP 59209 |
12.43 |
| 2026-04-05 00:00 |
12:08:50.48 |
-06:39:22.3 |
HIP 59209 |
12.48 |
| 2026-04-05 12:00 |
12:08:47.88 |
-06:39:05.3 |
HIP 59209 |
12.58 |
| 2026-04-06 00:00 |
12:08:45.28 |
-06:38:48.3 |
HIP 59209 |
12.71 |
| 2026-04-06 12:00 |
12:08:42.70 |
-06:38:31.2 |
HIP 59209 |
12.88 |
| 2026-04-07 00:00 |
12:08:40.12 |
-06:38:14.2 |
HIP 59209 |
13.09 |
| 2026-04-07 12:00 |
12:08:37.54 |
-06:37:57.2 |
HIP 59209 |
13.33 |
| 2026-04-08 00:00 |
12:08:34.97 |
-06:37:40.2 |
HIP 59209 |
13.60 |
| 2026-04-08 12:00 |
12:08:32.41 |
-06:37:23.2 |
HIP 59209 |
13.90 |
| 2026-04-09 00:00 |
12:08:29.86 |
-06:37:06.2 |
HIP 59209 |
14.23 |
| 2026-04-09 12:00 |
12:08:27.31 |
-06:36:49.2 |
HIP 59209 |
14.58 |
| 2026-04-10 00:00 |
12:08:24.77 |
-06:36:32.2 |
HIP 59209 |
14.96 |
| 2026-04-10 12:00 |
12:08:22.24 |
-06:36:15.3 |
HIP 59209 |
15.35 |
| 2026-04-11 00:00 |
12:08:19.71 |
-06:35:58.3 |
HIP 59209 |
15.77 |
| 2026-04-11 12:00 |
12:08:17.20 |
-06:35:41.4 |
HIP 59209 |
16.21 |
| 2026-04-12 00:00 |
12:08:14.69 |
-06:35:24.4 |
HIP 59209 |
16.66 |
| 2026-04-12 12:00 |
12:08:12.19 |
-06:35:07.5 |
HIP 59209 |
17.12 |
| 2026-04-13 00:00 |
12:08:09.70 |
-06:34:50.6 |
HIP 59108 |
17.55 |
| 2026-04-13 12:00 |
12:08:07.22 |
-06:34:33.8 |
HIP 59108 |
17.26 |
| 2026-04-14 00:00 |
12:08:04.74 |
-06:34:16.9 |
HIP 59108 |
17.00 |
| 2026-04-14 12:00 |
12:08:02.28 |
-06:34:00.1 |
HIP 59108 |
16.75 |
| 2026-04-15 00:00 |
12:07:59.82 |
-06:33:43.3 |
HIP 59108 |
16.54 |
| 2026-04-15 12:00 |
12:07:57.38 |
-06:33:26.5 |
HIP 59108 |
16.35 |
| 2026-04-16 00:00 |
12:07:54.94 |
-06:33:09.8 |
HIP 59108 |
16.18 |