| Parameter |
Value |
| Designation |
C/1972 X1 (Araya) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1972-12-18T23:37:01.591680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:22Z |
| Obs used |
71 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1973-06-27.0000000 |
| e |
0.99949725 |
| q (au) |
4.860840 |
| a (au) |
9668.528147 |
| i (deg) |
113.089959 |
| Ω (om, deg) |
314.886101 |
| ω (w, deg) |
267.211628 |
| M (ma, deg) |
0.000197 |
Magnitude
Scatter + Global Linear
$$
M_a = (-0.509 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-0.509 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.502 |
| 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) |
| 2026-05-12 00:00 |
18:38:55.16 |
+28:37:42.3 |
HIP 91392 |
8.27 |
| 2026-05-12 12:00 |
18:38:53.92 |
+28:37:56.2 |
HIP 91392 |
7.92 |
| 2026-05-13 00:00 |
18:38:52.67 |
+28:38:09.9 |
HIP 91392 |
7.57 |
| 2026-05-13 12:00 |
18:38:51.41 |
+28:38:23.6 |
HIP 91392 |
7.22 |
| 2026-05-14 00:00 |
18:38:50.14 |
+28:38:37.2 |
HIP 91392 |
6.87 |
| 2026-05-14 12:00 |
18:38:48.85 |
+28:38:50.6 |
HIP 91392 |
6.51 |
| 2026-05-15 00:00 |
18:38:47.56 |
+28:39:04.0 |
HIP 91392 |
6.16 |
| 2026-05-15 12:00 |
18:38:46.25 |
+28:39:17.2 |
HIP 91392 |
5.80 |
| 2026-05-16 00:00 |
18:38:44.94 |
+28:39:30.3 |
HIP 91392 |
5.45 |
| 2026-05-16 12:00 |
18:38:43.61 |
+28:39:43.2 |
HIP 91392 |
5.09 |
| 2026-05-17 00:00 |
18:38:42.27 |
+28:39:56.1 |
HIP 91392 |
4.74 |
| 2026-05-17 12:00 |
18:38:40.92 |
+28:40:08.8 |
HIP 91392 |
4.38 |
| 2026-05-18 00:00 |
18:38:39.56 |
+28:40:21.4 |
HIP 91392 |
4.03 |
| 2026-05-18 12:00 |
18:38:38.20 |
+28:40:33.9 |
HIP 91392 |
3.67 |
| 2026-05-19 00:00 |
18:38:36.82 |
+28:40:46.3 |
HIP 91392 |
3.32 |
| 2026-05-19 12:00 |
18:38:35.43 |
+28:40:58.5 |
HIP 91392 |
2.97 |
| 2026-05-20 00:00 |
18:38:34.03 |
+28:41:10.6 |
HIP 91392 |
2.62 |
| 2026-05-20 12:00 |
18:38:32.62 |
+28:41:22.6 |
HIP 91392 |
2.27 |
| 2026-05-21 00:00 |
18:38:31.20 |
+28:41:34.5 |
HIP 91392 |
1.93 |
| 2026-05-21 12:00 |
18:38:29.77 |
+28:41:46.2 |
HIP 91392 |
1.60 |
| 2026-05-22 00:00 |
18:38:28.33 |
+28:41:57.8 |
HIP 91392 |
1.29 |
| 2026-05-22 12:00 |
18:38:26.88 |
+28:42:09.3 |
HIP 91392 |
1.02 |
| 2026-05-23 00:00 |
18:38:25.42 |
+28:42:20.6 |
HIP 91392 |
0.83 |
| 2026-05-23 12:00 |
18:38:23.95 |
+28:42:31.8 |
HIP 91392 |
0.78 |
| 2026-05-24 00:00 |
18:38:22.48 |
+28:42:42.9 |
HIP 91392 |
0.89 |
| 2026-05-24 12:00 |
18:38:20.99 |
+28:42:53.9 |
HIP 91392 |
1.12 |
| 2026-05-25 00:00 |
18:38:19.50 |
+28:43:04.7 |
HIP 91392 |
1.41 |
| 2026-05-25 12:00 |
18:38:17.99 |
+28:43:15.4 |
HIP 91392 |
1.73 |
| 2026-05-26 00:00 |
18:38:16.48 |
+28:43:25.9 |
HIP 91392 |
2.07 |
| 2026-05-26 12:00 |
18:38:14.96 |
+28:43:36.3 |
HIP 91392 |
2.42 |
| 2026-05-27 00:00 |
18:38:13.43 |
+28:43:46.6 |
HIP 91392 |
2.78 |
| 2026-05-27 12:00 |
18:38:11.89 |
+28:43:56.7 |
HIP 91392 |
3.14 |
| 2026-05-28 00:00 |
18:38:10.35 |
+28:44:06.7 |
HIP 91392 |
3.51 |
| 2026-05-28 12:00 |
18:38:08.79 |
+28:44:16.6 |
HIP 91392 |
3.87 |
| 2026-05-29 00:00 |
18:38:07.23 |
+28:44:26.3 |
HIP 91392 |
4.24 |
| 2026-05-29 12:00 |
18:38:05.66 |
+28:44:35.9 |
HIP 91392 |
4.61 |
| 2026-05-30 00:00 |
18:38:04.08 |
+28:44:45.4 |
HIP 91392 |
4.98 |
| 2026-05-30 12:00 |
18:38:02.49 |
+28:44:54.7 |
HIP 91392 |
5.36 |
| 2026-05-31 00:00 |
18:38:00.90 |
+28:45:03.9 |
HIP 91392 |
5.73 |
| 2026-05-31 12:00 |
18:37:59.30 |
+28:45:12.9 |
HIP 91392 |
6.11 |
| 2026-06-01 00:00 |
18:37:57.69 |
+28:45:21.8 |
HIP 91392 |
6.48 |
| 2026-06-01 12:00 |
18:37:56.07 |
+28:45:30.5 |
HIP 91392 |
6.86 |
| 2026-06-02 00:00 |
18:37:54.45 |
+28:45:39.2 |
HIP 91392 |
7.24 |