| 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 |
-0.500 |
| 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) |
| 2026-07-29 00:00 |
18:34:33.45 |
+28:45:17.9 |
HIP 91056 |
0.93 |
| 2026-07-29 12:00 |
18:34:31.83 |
+28:45:09.1 |
HIP 91056 |
0.61 |
| 2026-07-30 00:00 |
18:34:30.22 |
+28:45:00.1 |
HIP 91056 |
0.43 |
| 2026-07-30 12:00 |
18:34:28.61 |
+28:44:51.1 |
HIP 91056 |
0.54 |
| 2026-07-31 00:00 |
18:34:27.02 |
+28:44:41.8 |
HIP 91056 |
0.83 |
| 2026-07-31 12:00 |
18:34:25.43 |
+28:44:32.5 |
HIP 91056 |
1.17 |
| 2026-08-01 00:00 |
18:34:23.85 |
+28:44:23.0 |
HIP 91056 |
1.54 |
| 2026-08-01 12:00 |
18:34:22.28 |
+28:44:13.4 |
HIP 91056 |
1.91 |
| 2026-08-02 00:00 |
18:34:20.71 |
+28:44:03.7 |
HIP 91056 |
2.28 |
| 2026-08-02 12:00 |
18:34:19.16 |
+28:43:53.8 |
HIP 91056 |
2.65 |
| 2026-08-03 00:00 |
18:34:17.61 |
+28:43:43.8 |
HIP 91056 |
3.03 |
| 2026-08-03 12:00 |
18:34:16.07 |
+28:43:33.7 |
HIP 91056 |
3.41 |
| 2026-08-04 00:00 |
18:34:14.54 |
+28:43:23.4 |
HIP 91056 |
3.78 |
| 2026-08-04 12:00 |
18:34:13.02 |
+28:43:13.0 |
HIP 91056 |
4.16 |
| 2026-08-05 00:00 |
18:34:11.50 |
+28:43:02.5 |
HIP 91056 |
4.53 |
| 2026-08-05 12:00 |
18:34:10.00 |
+28:42:51.9 |
HIP 91056 |
4.90 |
| 2026-08-06 00:00 |
18:34:08.50 |
+28:42:41.1 |
HIP 91056 |
5.28 |
| 2026-08-06 12:00 |
18:34:07.01 |
+28:42:30.2 |
HIP 91056 |
5.65 |
| 2026-08-07 00:00 |
18:34:05.53 |
+28:42:19.2 |
HIP 91056 |
6.02 |
| 2026-08-07 12:00 |
18:34:04.06 |
+28:42:08.1 |
HIP 91056 |
6.40 |
| 2026-08-08 00:00 |
18:34:02.60 |
+28:41:56.9 |
HIP 91056 |
6.77 |
| 2026-08-08 12:00 |
18:34:01.15 |
+28:41:45.5 |
HIP 91056 |
7.14 |
| 2026-08-09 00:00 |
18:33:59.71 |
+28:41:34.0 |
HIP 91056 |
7.51 |
| 2026-08-09 12:00 |
18:33:58.27 |
+28:41:22.4 |
HIP 91056 |
7.88 |
| 2026-08-10 00:00 |
18:33:56.85 |
+28:41:10.7 |
HIP 91056 |
8.24 |
| 2026-08-10 12:00 |
18:33:55.44 |
+28:40:58.8 |
HIP 91056 |
8.61 |
| 2026-08-11 00:00 |
18:33:54.04 |
+28:40:46.9 |
HIP 91056 |
8.98 |
| 2026-08-11 12:00 |
18:33:52.64 |
+28:40:34.8 |
HIP 91056 |
9.34 |
| 2026-08-12 00:00 |
18:33:51.26 |
+28:40:22.6 |
HIP 91056 |
9.71 |
| 2026-08-12 12:00 |
18:33:49.89 |
+28:40:10.3 |
HIP 91056 |
10.07 |
| 2026-08-13 00:00 |
18:33:48.52 |
+28:39:57.9 |
HIP 91056 |
10.43 |
| 2026-08-13 12:00 |
18:33:47.17 |
+28:39:45.4 |
HIP 91056 |
10.80 |
| 2026-08-14 00:00 |
18:33:45.83 |
+28:39:32.7 |
HIP 91056 |
11.16 |
| 2026-08-14 12:00 |
18:33:44.50 |
+28:39:20.0 |
HIP 91056 |
11.52 |
| 2026-08-15 00:00 |
18:33:43.18 |
+28:39:07.1 |
HIP 91056 |
11.88 |
| 2026-08-15 12:00 |
18:33:41.87 |
+28:38:54.2 |
HIP 91056 |
12.23 |
| 2026-08-16 00:00 |
18:33:40.57 |
+28:38:41.1 |
HIP 91056 |
12.59 |
| 2026-08-16 12:00 |
18:33:39.29 |
+28:38:27.9 |
HIP 91056 |
12.95 |
| 2026-08-17 00:00 |
18:33:38.01 |
+28:38:14.7 |
HIP 91056 |
13.30 |
| 2026-08-17 12:00 |
18:33:36.75 |
+28:38:01.3 |
HIP 91056 |
13.66 |
| 2026-08-18 00:00 |
18:33:35.49 |
+28:37:47.8 |
HIP 91056 |
14.01 |
| 2026-08-18 12:00 |
18:33:34.25 |
+28:37:34.2 |
HIP 91056 |
14.36 |
| 2026-08-19 00:00 |
18:33:33.02 |
+28:37:20.6 |
HIP 91056 |
14.71 |