C/2013 F3 (McNaught)
| Parameter |
Value |
| Designation |
C/2013 F3 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-05-25T06:10:32.957760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:32Z |
| Obs used |
301 |
| NEO |
- |
| M1 |
15.400 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-06-20.0000000 |
| e |
0.99704135 |
| q (au) |
2.252615 |
| a (au) |
761.365596 |
| i (deg) |
85.444578 |
| Ω (om, deg) |
266.108702 |
| ω (w, deg) |
18.757634 |
| M (ma, deg) |
0.001208 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.683 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.683 |
| n |
2.000 |
| gf |
0.998 |
| gb |
-0.997 |
| k |
1.000 |
| δ90 |
9.992 |
| 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 |
| 2013-05-31 |
2015-04-15 |
-19.7588 |
+7.282 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
05:27:48.25 |
+37:08:38.2 |
HIP 25605 |
7.32 |
| 2026-02-03 12:00 |
05:27:44.94 |
+37:08:19.1 |
HIP 25605 |
8.02 |
| 2026-02-04 00:00 |
05:27:41.66 |
+37:08:00.0 |
HIP 25605 |
8.71 |
| 2026-02-04 12:00 |
05:27:38.43 |
+37:07:40.8 |
HIP 25588 |
9.14 |
| 2026-02-05 00:00 |
05:27:35.24 |
+37:07:21.5 |
HIP 25588 |
9.31 |
| 2026-02-05 12:00 |
05:27:32.08 |
+37:07:02.2 |
HIP 25588 |
9.53 |
| 2026-02-06 00:00 |
05:27:28.97 |
+37:06:42.9 |
HIP 25588 |
9.78 |
| 2026-02-06 12:00 |
05:27:25.90 |
+37:06:23.5 |
HIP 25588 |
10.08 |
| 2026-02-07 00:00 |
05:27:22.87 |
+37:06:04.0 |
HIP 25588 |
10.40 |
| 2026-02-07 12:00 |
05:27:19.88 |
+37:05:44.5 |
HIP 25588 |
10.75 |
| 2026-02-08 00:00 |
05:27:16.93 |
+37:05:25.0 |
HIP 25588 |
11.12 |
| 2026-02-08 12:00 |
05:27:14.02 |
+37:05:05.4 |
HIP 25588 |
11.51 |
| 2026-02-09 00:00 |
05:27:11.15 |
+37:04:45.8 |
HIP 25588 |
11.92 |
| 2026-02-09 12:00 |
05:27:08.32 |
+37:04:26.2 |
HIP 25588 |
12.34 |
| 2026-02-10 00:00 |
05:27:05.54 |
+37:04:06.5 |
HIP 25588 |
12.77 |
| 2026-02-10 12:00 |
05:27:02.80 |
+37:03:46.7 |
HIP 25588 |
13.21 |
| 2026-02-11 00:00 |
05:27:00.10 |
+37:03:27.0 |
HIP 25588 |
13.66 |
| 2026-02-11 12:00 |
05:26:57.44 |
+37:03:07.2 |
HIP 25588 |
14.12 |
| 2026-02-12 00:00 |
05:26:54.83 |
+37:02:47.4 |
HIP 25588 |
14.58 |
| 2026-02-12 12:00 |
05:26:52.26 |
+37:02:27.5 |
HIP 25588 |
15.04 |
| 2026-02-13 00:00 |
05:26:49.73 |
+37:02:07.6 |
HIP 25588 |
15.50 |
| 2026-02-13 12:00 |
05:26:47.24 |
+37:01:47.7 |
HIP 25588 |
15.97 |
| 2026-02-14 00:00 |
05:26:44.80 |
+37:01:27.8 |
HIP 25588 |
16.43 |
| 2026-02-14 12:00 |
05:26:42.40 |
+37:01:07.8 |
HIP 25588 |
16.90 |
| 2026-02-15 00:00 |
05:26:40.05 |
+37:00:47.9 |
HIP 25588 |
17.36 |
| 2026-02-15 12:00 |
05:26:37.74 |
+37:00:27.9 |
HIP 25588 |
17.82 |
| 2026-02-16 00:00 |
05:26:35.47 |
+37:00:07.9 |
HIP 25588 |
18.28 |
| 2026-02-16 12:00 |
05:26:33.25 |
+36:59:47.8 |
HIP 25588 |
18.73 |
| 2026-02-17 00:00 |
05:26:31.07 |
+36:59:27.8 |
HIP 25588 |
19.18 |
| 2026-02-17 12:00 |
05:26:28.93 |
+36:59:07.7 |
HIP 25588 |
19.63 |
| 2026-02-18 00:00 |
05:26:26.85 |
+36:58:47.6 |
HIP 25588 |
20.07 |
| 2026-02-18 12:00 |
05:26:24.80 |
+36:58:27.5 |
HIP 25588 |
20.51 |
| 2026-02-19 00:00 |
05:26:22.80 |
+36:58:07.4 |
HIP 25588 |
20.94 |
| 2026-02-19 12:00 |
05:26:20.84 |
+36:57:47.3 |
HIP 25588 |
21.37 |
| 2026-02-20 00:00 |
05:26:18.93 |
+36:57:27.2 |
HIP 25588 |
21.80 |
| 2026-02-20 12:00 |
05:26:17.07 |
+36:57:07.1 |
HIP 25588 |
22.22 |
| 2026-02-21 00:00 |
05:26:15.25 |
+36:56:47.0 |
HIP 25588 |
22.63 |
| 2026-02-21 12:00 |
05:26:13.47 |
+36:56:26.8 |
HIP 25588 |
23.04 |
| 2026-02-22 00:00 |
05:26:11.74 |
+36:56:06.7 |
HIP 25588 |
23.44 |
| 2026-02-22 12:00 |
05:26:10.06 |
+36:55:46.6 |
HIP 25588 |
23.83 |
| 2026-02-23 00:00 |
05:26:08.42 |
+36:55:26.4 |
HIP 25588 |
24.23 |
| 2026-02-23 12:00 |
05:26:06.82 |
+36:55:06.3 |
HIP 25588 |
24.61 |
| 2026-02-24 00:00 |
05:26:05.28 |
+36:54:46.2 |
HIP 25588 |
24.99 |