C/1983 J2 (IRAS)
| Parameter |
Value |
| Designation |
C/1983 J2 (IRAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1983-01-18T15:30:12.680640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:31Z |
| Obs used |
7 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1983-05-30.0000000 |
| e |
0.99471612 |
| q (au) |
1.416663 |
| a (au) |
268.110599 |
| i (deg) |
152.173465 |
| Ω (om, deg) |
119.690042 |
| ω (w, deg) |
227.019078 |
| M (ma, deg) |
0.029490 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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 |
06:04:47.85 |
+37:35:06.8 |
HIP 28820 |
22.93 |
| 2026-02-03 12:00 |
06:04:46.09 |
+37:35:02.7 |
HIP 28820 |
23.04 |
| 2026-02-04 00:00 |
06:04:44.34 |
+37:34:58.5 |
HIP 28820 |
23.16 |
| 2026-02-04 12:00 |
06:04:42.61 |
+37:34:54.3 |
HIP 28820 |
23.29 |
| 2026-02-05 00:00 |
06:04:40.89 |
+37:34:50.0 |
HIP 28820 |
23.42 |
| 2026-02-05 12:00 |
06:04:39.19 |
+37:34:45.8 |
HIP 28820 |
23.55 |
| 2026-02-06 00:00 |
06:04:37.50 |
+37:34:41.4 |
HIP 28820 |
23.69 |
| 2026-02-06 12:00 |
06:04:35.83 |
+37:34:37.0 |
HIP 28820 |
23.83 |
| 2026-02-07 00:00 |
06:04:34.17 |
+37:34:32.6 |
HIP 28727 |
23.82 |
| 2026-02-07 12:00 |
06:04:32.52 |
+37:34:28.2 |
HIP 28727 |
23.67 |
| 2026-02-08 00:00 |
06:04:30.89 |
+37:34:23.7 |
HIP 28727 |
23.52 |
| 2026-02-08 12:00 |
06:04:29.28 |
+37:34:19.1 |
HIP 28727 |
23.38 |
| 2026-02-09 00:00 |
06:04:27.68 |
+37:34:14.5 |
HIP 28727 |
23.23 |
| 2026-02-09 12:00 |
06:04:26.10 |
+37:34:09.9 |
HIP 28727 |
23.10 |
| 2026-02-10 00:00 |
06:04:24.53 |
+37:34:05.2 |
HIP 28727 |
22.96 |
| 2026-02-10 12:00 |
06:04:22.98 |
+37:34:00.5 |
HIP 28727 |
22.83 |
| 2026-02-11 00:00 |
06:04:21.45 |
+37:33:55.8 |
HIP 28727 |
22.71 |
| 2026-02-11 12:00 |
06:04:19.93 |
+37:33:51.0 |
HIP 28727 |
22.58 |
| 2026-02-12 00:00 |
06:04:18.43 |
+37:33:46.2 |
HIP 28727 |
22.46 |
| 2026-02-12 12:00 |
06:04:16.94 |
+37:33:41.3 |
HIP 28727 |
22.35 |
| 2026-02-13 00:00 |
06:04:15.47 |
+37:33:36.4 |
HIP 28727 |
22.23 |
| 2026-02-13 12:00 |
06:04:14.02 |
+37:33:31.5 |
HIP 28727 |
22.13 |
| 2026-02-14 00:00 |
06:04:12.58 |
+37:33:26.5 |
HIP 28727 |
22.02 |
| 2026-02-14 12:00 |
06:04:11.16 |
+37:33:21.5 |
HIP 28727 |
21.92 |
| 2026-02-15 00:00 |
06:04:09.75 |
+37:33:16.5 |
HIP 28727 |
21.81 |
| 2026-02-15 12:00 |
06:04:08.37 |
+37:33:11.4 |
HIP 28727 |
21.72 |
| 2026-02-16 00:00 |
06:04:07.00 |
+37:33:06.3 |
HIP 28727 |
21.62 |
| 2026-02-16 12:00 |
06:04:05.65 |
+37:33:01.2 |
HIP 28727 |
21.53 |
| 2026-02-17 00:00 |
06:04:04.31 |
+37:32:56.0 |
HIP 28727 |
21.44 |
| 2026-02-17 12:00 |
06:04:02.99 |
+37:32:50.8 |
HIP 28727 |
21.36 |
| 2026-02-18 00:00 |
06:04:01.69 |
+37:32:45.5 |
HIP 28727 |
21.27 |
| 2026-02-18 12:00 |
06:04:00.41 |
+37:32:40.3 |
HIP 28727 |
21.19 |
| 2026-02-19 00:00 |
06:03:59.14 |
+37:32:35.0 |
HIP 28727 |
21.11 |
| 2026-02-19 12:00 |
06:03:57.90 |
+37:32:29.6 |
HIP 28727 |
21.04 |
| 2026-02-20 00:00 |
06:03:56.67 |
+37:32:24.3 |
HIP 28727 |
20.96 |
| 2026-02-20 12:00 |
06:03:55.46 |
+37:32:18.9 |
HIP 28727 |
20.89 |
| 2026-02-21 00:00 |
06:03:54.26 |
+37:32:13.4 |
HIP 28727 |
20.82 |
| 2026-02-21 12:00 |
06:03:53.09 |
+37:32:08.0 |
HIP 28727 |
20.76 |
| 2026-02-22 00:00 |
06:03:51.93 |
+37:32:02.5 |
HIP 28727 |
20.69 |
| 2026-02-22 12:00 |
06:03:50.79 |
+37:31:57.0 |
HIP 28727 |
20.63 |
| 2026-02-23 00:00 |
06:03:49.67 |
+37:31:51.5 |
HIP 28727 |
20.56 |
| 2026-02-23 12:00 |
06:03:48.56 |
+37:31:45.9 |
HIP 28727 |
20.50 |
| 2026-02-24 00:00 |
06:03:47.48 |
+37:31:40.3 |
HIP 28727 |
20.45 |