C/1978 G2 (McNaught-Tritton)
| Parameter |
Value |
| Designation |
C/1978 G2 (McNaught-Tritton) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1978-08-23T23:05:11.348160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:27Z |
| Obs used |
5 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1978-08-28.0000000 |
| e |
1.00462671 |
| q (au) |
6.284334 |
| a (au) |
-1358.272229 |
| i (deg) |
153.180957 |
| Ω (om, deg) |
72.213979 |
| ω (w, deg) |
229.460098 |
| M (ma, deg) |
0.000080 |
Magnitude
Scatter + Global Linear
$$
M_a = (1.134 + 5.745\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
1.134 |
| n |
5.745 |
| gf |
0.991 |
| gb |
-0.731 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
03:40:45.29 |
+26:04:13.3 |
HIP 17245 |
29.38 |
| 2026-02-03 12:00 |
03:40:44.74 |
+26:04:09.3 |
HIP 17245 |
29.36 |
| 2026-02-04 00:00 |
03:40:44.20 |
+26:04:05.4 |
HIP 17245 |
29.35 |
| 2026-02-04 12:00 |
03:40:43.68 |
+26:04:01.4 |
HIP 17245 |
29.34 |
| 2026-02-05 00:00 |
03:40:43.18 |
+26:03:57.6 |
HIP 17245 |
29.33 |
| 2026-02-05 12:00 |
03:40:42.69 |
+26:03:53.7 |
HIP 17245 |
29.31 |
| 2026-02-06 00:00 |
03:40:42.22 |
+26:03:49.9 |
HIP 17245 |
29.30 |
| 2026-02-06 12:00 |
03:40:41.77 |
+26:03:46.2 |
HIP 17245 |
29.28 |
| 2026-02-07 00:00 |
03:40:41.33 |
+26:03:42.5 |
HIP 17245 |
29.27 |
| 2026-02-07 12:00 |
03:40:40.91 |
+26:03:38.9 |
HIP 17245 |
29.25 |
| 2026-02-08 00:00 |
03:40:40.50 |
+26:03:35.3 |
HIP 17245 |
29.24 |
| 2026-02-08 12:00 |
03:40:40.11 |
+26:03:31.7 |
HIP 17245 |
29.22 |
| 2026-02-09 00:00 |
03:40:39.74 |
+26:03:28.2 |
HIP 17245 |
29.21 |
| 2026-02-09 12:00 |
03:40:39.39 |
+26:03:24.8 |
HIP 17245 |
29.19 |
| 2026-02-10 00:00 |
03:40:39.05 |
+26:03:21.4 |
HIP 17245 |
29.17 |
| 2026-02-10 12:00 |
03:40:38.73 |
+26:03:18.0 |
HIP 17245 |
29.15 |
| 2026-02-11 00:00 |
03:40:38.42 |
+26:03:14.7 |
HIP 17245 |
29.14 |
| 2026-02-11 12:00 |
03:40:38.13 |
+26:03:11.5 |
HIP 17245 |
29.12 |
| 2026-02-12 00:00 |
03:40:37.86 |
+26:03:08.3 |
HIP 17245 |
29.10 |
| 2026-02-12 12:00 |
03:40:37.60 |
+26:03:05.1 |
HIP 17245 |
29.08 |
| 2026-02-13 00:00 |
03:40:37.37 |
+26:03:02.0 |
HIP 17245 |
29.05 |
| 2026-02-13 12:00 |
03:40:37.14 |
+26:02:59.0 |
HIP 17245 |
29.03 |
| 2026-02-14 00:00 |
03:40:36.94 |
+26:02:56.0 |
HIP 17245 |
29.01 |
| 2026-02-14 12:00 |
03:40:36.75 |
+26:02:53.0 |
HIP 17245 |
28.98 |
| 2026-02-15 00:00 |
03:40:36.58 |
+26:02:50.2 |
HIP 17245 |
28.96 |
| 2026-02-15 12:00 |
03:40:36.42 |
+26:02:47.3 |
HIP 17245 |
28.93 |
| 2026-02-16 00:00 |
03:40:36.28 |
+26:02:44.5 |
HIP 17245 |
28.91 |
| 2026-02-16 12:00 |
03:40:36.16 |
+26:02:41.8 |
HIP 17245 |
28.88 |
| 2026-02-17 00:00 |
03:40:36.06 |
+26:02:39.1 |
HIP 17245 |
28.85 |
| 2026-02-17 12:00 |
03:40:35.97 |
+26:02:36.5 |
HIP 17245 |
28.82 |
| 2026-02-18 00:00 |
03:40:35.89 |
+26:02:33.9 |
HIP 17245 |
28.79 |
| 2026-02-18 12:00 |
03:40:35.84 |
+26:02:31.4 |
HIP 17245 |
28.76 |
| 2026-02-19 00:00 |
03:40:35.80 |
+26:02:28.9 |
HIP 17245 |
28.73 |
| 2026-02-19 12:00 |
03:40:35.78 |
+26:02:26.5 |
HIP 17245 |
28.70 |
| 2026-02-20 00:00 |
03:40:35.77 |
+26:02:24.1 |
HIP 17245 |
28.66 |
| 2026-02-20 12:00 |
03:40:35.78 |
+26:02:21.8 |
HIP 17245 |
28.63 |
| 2026-02-21 00:00 |
03:40:35.81 |
+26:02:19.6 |
HIP 17245 |
28.59 |
| 2026-02-21 12:00 |
03:40:35.86 |
+26:02:17.4 |
HIP 17245 |
28.55 |
| 2026-02-22 00:00 |
03:40:35.92 |
+26:02:15.2 |
HIP 17245 |
28.52 |
| 2026-02-22 12:00 |
03:40:35.99 |
+26:02:13.1 |
HIP 17245 |
28.48 |
| 2026-02-23 00:00 |
03:40:36.09 |
+26:02:11.1 |
HIP 17245 |
28.44 |
| 2026-02-23 12:00 |
03:40:36.20 |
+26:02:09.1 |
HIP 17245 |
28.40 |
| 2026-02-24 00:00 |
03:40:36.32 |
+26:02:07.2 |
HIP 17245 |
28.35 |