| 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) |
| 2026-06-01 00:00 |
06:05:55.61 |
+37:15:06.0 |
HIP 29003 |
15.70 |
| 2026-06-01 12:00 |
06:05:57.59 |
+37:15:03.8 |
HIP 29003 |
15.32 |
| 2026-06-02 00:00 |
06:05:59.58 |
+37:15:01.6 |
HIP 29003 |
14.94 |
| 2026-06-02 12:00 |
06:06:01.58 |
+37:14:59.5 |
HIP 29003 |
14.55 |
| 2026-06-03 00:00 |
06:06:03.58 |
+37:14:57.4 |
HIP 29003 |
14.17 |
| 2026-06-03 12:00 |
06:06:05.58 |
+37:14:55.3 |
HIP 29003 |
13.78 |
| 2026-06-04 00:00 |
06:06:07.60 |
+37:14:53.3 |
HIP 29003 |
13.40 |
| 2026-06-04 12:00 |
06:06:09.61 |
+37:14:51.4 |
HIP 29003 |
13.01 |
| 2026-06-05 00:00 |
06:06:11.64 |
+37:14:49.5 |
HIP 29003 |
12.63 |
| 2026-06-05 12:00 |
06:06:13.66 |
+37:14:47.7 |
HIP 29003 |
12.25 |
| 2026-06-06 00:00 |
06:06:15.70 |
+37:14:45.9 |
HIP 29003 |
11.87 |
| 2026-06-06 12:00 |
06:06:17.74 |
+37:14:44.1 |
HIP 29003 |
11.49 |
| 2026-06-07 00:00 |
06:06:19.78 |
+37:14:42.4 |
HIP 29003 |
11.11 |
| 2026-06-07 12:00 |
06:06:21.83 |
+37:14:40.7 |
HIP 29003 |
10.73 |
| 2026-06-08 00:00 |
06:06:23.88 |
+37:14:39.1 |
HIP 29003 |
10.35 |
| 2026-06-08 12:00 |
06:06:25.94 |
+37:14:37.6 |
HIP 29003 |
9.98 |
| 2026-06-09 00:00 |
06:06:28.00 |
+37:14:36.1 |
HIP 29003 |
9.61 |
| 2026-06-09 12:00 |
06:06:30.07 |
+37:14:34.6 |
HIP 29003 |
9.24 |
| 2026-06-10 00:00 |
06:06:32.14 |
+37:14:33.2 |
HIP 29003 |
8.87 |
| 2026-06-10 12:00 |
06:06:34.21 |
+37:14:31.8 |
HIP 29003 |
8.51 |
| 2026-06-11 00:00 |
06:06:36.29 |
+37:14:30.5 |
HIP 29003 |
8.16 |
| 2026-06-11 12:00 |
06:06:38.37 |
+37:14:29.2 |
HIP 29003 |
7.81 |
| 2026-06-12 00:00 |
06:06:40.46 |
+37:14:28.0 |
HIP 29003 |
7.47 |
| 2026-06-12 12:00 |
06:06:42.55 |
+37:14:26.9 |
HIP 29003 |
7.13 |
| 2026-06-13 00:00 |
06:06:44.64 |
+37:14:25.7 |
HIP 29003 |
6.80 |
| 2026-06-13 12:00 |
06:06:46.73 |
+37:14:24.7 |
HIP 29003 |
6.49 |
| 2026-06-14 00:00 |
06:06:48.83 |
+37:14:23.6 |
HIP 29003 |
6.18 |
| 2026-06-14 12:00 |
06:06:50.93 |
+37:14:22.7 |
HIP 29003 |
5.90 |
| 2026-06-15 00:00 |
06:06:53.03 |
+37:14:21.7 |
HIP 29003 |
5.62 |
| 2026-06-15 12:00 |
06:06:55.14 |
+37:14:20.9 |
HIP 29003 |
5.37 |
| 2026-06-16 00:00 |
06:06:57.25 |
+37:14:20.0 |
HIP 29003 |
5.14 |
| 2026-06-16 12:00 |
06:06:59.36 |
+37:14:19.3 |
HIP 29003 |
4.93 |
| 2026-06-17 00:00 |
06:07:01.47 |
+37:14:18.5 |
HIP 29003 |
4.76 |
| 2026-06-17 12:00 |
06:07:03.58 |
+37:14:17.9 |
HIP 29003 |
4.61 |
| 2026-06-18 00:00 |
06:07:05.70 |
+37:14:17.2 |
HIP 29003 |
4.50 |
| 2026-06-18 12:00 |
06:07:07.81 |
+37:14:16.7 |
HIP 29003 |
4.43 |
| 2026-06-19 00:00 |
06:07:09.93 |
+37:14:16.1 |
HIP 29003 |
4.41 |
| 2026-06-19 12:00 |
06:07:12.05 |
+37:14:15.7 |
HIP 29003 |
4.42 |
| 2026-06-20 00:00 |
06:07:14.17 |
+37:14:15.2 |
HIP 29003 |
4.47 |
| 2026-06-20 12:00 |
06:07:16.29 |
+37:14:14.9 |
HIP 29003 |
4.56 |
| 2026-06-21 00:00 |
06:07:18.41 |
+37:14:14.5 |
HIP 29003 |
4.69 |
| 2026-06-21 12:00 |
06:07:20.53 |
+37:14:14.3 |
HIP 29003 |
4.85 |
| 2026-06-22 00:00 |
06:07:22.66 |
+37:14:14.0 |
HIP 29003 |
5.05 |