66P/du Toit
| Parameter |
Value |
| Designation |
66P/du Toit |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-05-20T11:15:17.081280Z |
| Orbit solution date (soln_date, UTC) |
2019-06-03T14:53:20Z |
| Obs used |
547 |
| NEO |
Yes |
| M1 |
15.700 |
| K1 |
7.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-10-31.0000000 |
| e |
0.78656817 |
| q (au) |
1.285451 |
| a (au) |
6.022773 |
| i (deg) |
18.668971 |
| Ω (om, deg) |
21.999851 |
| ω (w, deg) |
257.342734 |
| M (ma, deg) |
273.482032 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.128 + 5.614\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.128 |
| n |
5.614 |
| gf |
0.972 |
| gb |
-0.780 |
| k |
0.995 |
| δ90 |
9.986 |
| 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 |
| 2018-01-14 |
2018-05-20 |
+20.2696 |
-4.971 |
| 2018-05-21 |
2018-10-04 |
+19.3494 |
-5.821 |
| 2018-10-04 |
2018-11-10 |
-27.9509 |
+9.461 |
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 |
06:33:13.71 |
+42:56:37.3 |
HIP 31307 |
12.58 |
| 2026-02-03 12:00 |
06:33:02.81 |
+42:56:10.4 |
HIP 31240 |
13.20 |
| 2026-02-04 00:00 |
06:32:52.01 |
+42:55:43.0 |
HIP 31240 |
13.98 |
| 2026-02-04 12:00 |
06:32:41.30 |
+42:55:15.1 |
HIP 31240 |
15.00 |
| 2026-02-05 00:00 |
06:32:30.70 |
+42:54:46.7 |
HIP 31240 |
16.21 |
| 2026-02-05 12:00 |
06:32:20.19 |
+42:54:17.8 |
HIP 31240 |
17.56 |
| 2026-02-06 00:00 |
06:32:09.79 |
+42:53:48.4 |
HIP 31240 |
19.01 |
| 2026-02-06 12:00 |
06:31:59.49 |
+42:53:18.5 |
HIP 31240 |
20.55 |
| 2026-02-07 00:00 |
06:31:49.29 |
+42:52:48.2 |
HIP 31240 |
22.14 |
| 2026-02-07 12:00 |
06:31:39.20 |
+42:52:17.4 |
HIP 31240 |
23.78 |
| 2026-02-08 00:00 |
06:31:29.21 |
+42:51:46.1 |
HIP 31240 |
25.44 |
| 2026-02-08 12:00 |
06:31:19.32 |
+42:51:14.3 |
HIP 31240 |
27.13 |
| 2026-02-09 00:00 |
06:31:09.55 |
+42:50:42.1 |
HIP 31240 |
28.83 |
| 2026-02-09 12:00 |
06:30:59.88 |
+42:50:09.5 |
HIP 31240 |
30.55 |
| 2026-02-10 00:00 |
06:30:50.32 |
+42:49:36.4 |
HIP 30814 |
29.88 |
| 2026-02-10 12:00 |
06:30:40.87 |
+42:49:02.8 |
HIP 30814 |
28.67 |
| 2026-02-11 00:00 |
06:30:31.54 |
+42:48:28.8 |
HIP 30814 |
27.55 |
| 2026-02-11 12:00 |
06:30:22.31 |
+42:47:54.4 |
HIP 30814 |
26.52 |
| 2026-02-12 00:00 |
06:30:13.20 |
+42:47:19.6 |
HIP 30814 |
25.60 |
| 2026-02-12 12:00 |
06:30:04.19 |
+42:46:44.3 |
HIP 30814 |
24.78 |
| 2026-02-13 00:00 |
06:29:55.31 |
+42:46:08.7 |
HIP 30814 |
24.09 |
| 2026-02-13 12:00 |
06:29:46.54 |
+42:45:32.6 |
HIP 30814 |
23.52 |
| 2026-02-14 00:00 |
06:29:37.88 |
+42:44:56.1 |
HIP 30814 |
23.08 |
| 2026-02-14 12:00 |
06:29:29.34 |
+42:44:19.3 |
HIP 30814 |
22.78 |
| 2026-02-15 00:00 |
06:29:20.92 |
+42:43:42.0 |
HIP 30814 |
22.61 |
| 2026-02-15 12:00 |
06:29:12.62 |
+42:43:04.4 |
HIP 30814 |
22.58 |
| 2026-02-16 00:00 |
06:29:04.43 |
+42:42:26.3 |
HIP 30814 |
22.68 |
| 2026-02-16 12:00 |
06:28:56.37 |
+42:41:47.9 |
HIP 30814 |
22.91 |
| 2026-02-17 00:00 |
06:28:48.42 |
+42:41:09.2 |
HIP 30814 |
23.26 |
| 2026-02-17 12:00 |
06:28:40.60 |
+42:40:30.0 |
HIP 30814 |
23.71 |
| 2026-02-18 00:00 |
06:28:32.90 |
+42:39:50.6 |
HIP 30814 |
24.27 |
| 2026-02-18 12:00 |
06:28:25.32 |
+42:39:10.7 |
HIP 30814 |
24.92 |
| 2026-02-19 00:00 |
06:28:17.86 |
+42:38:30.6 |
HIP 30814 |
25.64 |
| 2026-02-19 12:00 |
06:28:10.53 |
+42:37:50.0 |
HIP 30814 |
26.44 |
| 2026-02-20 00:00 |
06:28:03.32 |
+42:37:09.2 |
HIP 30814 |
27.30 |
| 2026-02-20 12:00 |
06:27:56.23 |
+42:36:28.0 |
HIP 30814 |
28.22 |
| 2026-02-21 00:00 |
06:27:49.27 |
+42:35:46.5 |
HIP 30814 |
29.17 |
| 2026-02-21 12:00 |
06:27:42.44 |
+42:35:04.7 |
HIP 30526 |
30.03 |
| 2026-02-22 00:00 |
06:27:35.73 |
+42:34:22.6 |
HIP 30526 |
28.75 |
| 2026-02-22 12:00 |
06:27:29.15 |
+42:33:40.2 |
HIP 30526 |
27.51 |
| 2026-02-23 00:00 |
06:27:22.69 |
+42:32:57.5 |
HIP 30526 |
26.31 |
| 2026-02-23 12:00 |
06:27:16.36 |
+42:32:14.5 |
HIP 30526 |
25.15 |
| 2026-02-24 00:00 |
06:27:10.16 |
+42:31:31.2 |
HIP 30526 |
24.04 |