| Parameter |
Value |
| Designation |
C/2004 R2 (ASAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2004-10-07T21:32:12.880320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:42Z |
| Obs used |
66 |
| NEO |
- |
| M1 |
10.000 |
| K1 |
6.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2004-09-15.0000000 |
| e |
0.99999993 |
| q (au) |
0.112836 |
| a (au) |
1619082.250620 |
| i (deg) |
63.173694 |
| Ω (om, deg) |
182.463575 |
| ω (w, deg) |
5.353183 |
| M (ma, deg) |
360.000000 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.995 + 2.096\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.995 |
| n |
2.096 |
| 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) |
| 2026-09-20 00:00 |
00:08:21.96 |
+01:20:05.4 |
HIP 769 |
17.39 |
| 2026-09-20 12:00 |
00:08:19.47 |
+01:19:48.8 |
HIP 628 |
17.25 |
| 2026-09-21 00:00 |
00:08:16.98 |
+01:19:32.2 |
HIP 628 |
16.68 |
| 2026-09-21 12:00 |
00:08:14.49 |
+01:19:15.6 |
HIP 628 |
16.11 |
| 2026-09-22 00:00 |
00:08:12.00 |
+01:18:59.0 |
HIP 628 |
15.54 |
| 2026-09-22 12:00 |
00:08:09.51 |
+01:18:42.4 |
HIP 628 |
14.99 |
| 2026-09-23 00:00 |
00:08:07.01 |
+01:18:25.8 |
HIP 628 |
14.45 |
| 2026-09-23 12:00 |
00:08:04.52 |
+01:18:09.1 |
HIP 628 |
13.92 |
| 2026-09-24 00:00 |
00:08:02.02 |
+01:17:52.5 |
HIP 628 |
13.40 |
| 2026-09-24 12:00 |
00:07:59.53 |
+01:17:35.9 |
HIP 628 |
12.90 |
| 2026-09-25 00:00 |
00:07:57.03 |
+01:17:19.2 |
HIP 628 |
12.42 |
| 2026-09-25 12:00 |
00:07:54.54 |
+01:17:02.6 |
HIP 628 |
11.95 |
| 2026-09-26 00:00 |
00:07:52.04 |
+01:16:45.9 |
HIP 628 |
11.51 |
| 2026-09-26 12:00 |
00:07:49.55 |
+01:16:29.3 |
HIP 628 |
11.09 |
| 2026-09-27 00:00 |
00:07:47.05 |
+01:16:12.6 |
HIP 628 |
10.70 |
| 2026-09-27 12:00 |
00:07:44.56 |
+01:15:56.0 |
HIP 628 |
10.34 |
| 2026-09-28 00:00 |
00:07:42.07 |
+01:15:39.3 |
HIP 628 |
10.01 |
| 2026-09-28 12:00 |
00:07:39.57 |
+01:15:22.7 |
HIP 628 |
9.72 |
| 2026-09-29 00:00 |
00:07:37.08 |
+01:15:06.0 |
HIP 628 |
9.47 |
| 2026-09-29 12:00 |
00:07:34.60 |
+01:14:49.4 |
HIP 628 |
9.27 |
| 2026-09-30 00:00 |
00:07:32.11 |
+01:14:32.8 |
HIP 628 |
9.11 |
| 2026-09-30 12:00 |
00:07:29.63 |
+01:14:16.2 |
HIP 628 |
9.00 |
| 2026-10-01 00:00 |
00:07:27.14 |
+01:13:59.6 |
HIP 628 |
8.94 |
| 2026-10-01 12:00 |
00:07:24.66 |
+01:13:43.0 |
HIP 628 |
8.93 |
| 2026-10-02 00:00 |
00:07:22.18 |
+01:13:26.4 |
HIP 628 |
8.97 |
| 2026-10-02 12:00 |
00:07:19.71 |
+01:13:09.9 |
HIP 628 |
9.06 |
| 2026-10-03 00:00 |
00:07:17.24 |
+01:12:53.3 |
HIP 628 |
9.20 |
| 2026-10-03 12:00 |
00:07:14.77 |
+01:12:36.8 |
HIP 628 |
9.39 |
| 2026-10-04 00:00 |
00:07:12.30 |
+01:12:20.3 |
HIP 628 |
9.62 |
| 2026-10-04 12:00 |
00:07:09.84 |
+01:12:03.8 |
HIP 628 |
9.90 |
| 2026-10-05 00:00 |
00:07:07.38 |
+01:11:47.3 |
HIP 628 |
10.20 |
| 2026-10-05 12:00 |
00:07:04.92 |
+01:11:30.9 |
HIP 628 |
10.55 |
| 2026-10-06 00:00 |
00:07:02.47 |
+01:11:14.4 |
HIP 628 |
10.92 |
| 2026-10-06 12:00 |
00:07:00.03 |
+01:10:58.0 |
HIP 628 |
11.32 |
| 2026-10-07 00:00 |
00:06:57.58 |
+01:10:41.7 |
HIP 628 |
11.74 |
| 2026-10-07 12:00 |
00:06:55.14 |
+01:10:25.3 |
HIP 628 |
12.18 |
| 2026-10-08 00:00 |
00:06:52.71 |
+01:10:09.0 |
HIP 628 |
12.65 |
| 2026-10-08 12:00 |
00:06:50.28 |
+01:09:52.7 |
HIP 628 |
13.13 |
| 2026-10-09 00:00 |
00:06:47.86 |
+01:09:36.5 |
HIP 628 |
13.62 |
| 2026-10-09 12:00 |
00:06:45.44 |
+01:09:20.3 |
HIP 628 |
14.13 |
| 2026-10-10 00:00 |
00:06:43.03 |
+01:09:04.1 |
HIP 628 |
14.64 |
| 2026-10-10 12:00 |
00:06:40.63 |
+01:08:47.9 |
HIP 628 |
15.17 |
| 2026-10-11 00:00 |
00:06:38.23 |
+01:08:31.8 |
HIP 628 |
15.71 |