| 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) |
| 2026-03-26 00:00 |
00:08:00.05 |
+01:19:05.0 |
HIP 628 |
14.33 |
| 2026-03-26 12:00 |
00:08:02.53 |
+01:19:20.7 |
HIP 628 |
14.80 |
| 2026-03-27 00:00 |
00:08:05.00 |
+01:19:36.4 |
HIP 628 |
15.29 |
| 2026-03-27 12:00 |
00:08:07.47 |
+01:19:52.0 |
HIP 628 |
15.78 |
| 2026-03-28 00:00 |
00:08:09.95 |
+01:20:07.7 |
HIP 628 |
16.29 |
| 2026-03-28 12:00 |
00:08:12.42 |
+01:20:23.3 |
HIP 628 |
16.81 |
| 2026-03-29 00:00 |
00:08:14.89 |
+01:20:38.9 |
HIP 628 |
17.34 |
| 2026-03-29 12:00 |
00:08:17.35 |
+01:20:54.5 |
HIP 628 |
17.88 |
| 2026-03-30 00:00 |
00:08:19.81 |
+01:21:10.1 |
HIP 769 |
18.25 |
| 2026-03-30 12:00 |
00:08:22.28 |
+01:21:25.7 |
HIP 769 |
17.78 |
| 2026-03-31 00:00 |
00:08:24.73 |
+01:21:41.3 |
HIP 769 |
17.32 |
| 2026-03-31 12:00 |
00:08:27.19 |
+01:21:56.8 |
HIP 769 |
16.87 |
| 2026-04-01 00:00 |
00:08:29.64 |
+01:22:12.4 |
HIP 769 |
16.44 |
| 2026-04-01 12:00 |
00:08:32.09 |
+01:22:27.9 |
HIP 769 |
16.02 |
| 2026-04-02 00:00 |
00:08:34.53 |
+01:22:43.4 |
HIP 769 |
15.62 |
| 2026-04-02 12:00 |
00:08:36.98 |
+01:22:58.9 |
HIP 769 |
15.24 |
| 2026-04-03 00:00 |
00:08:39.41 |
+01:23:14.3 |
HIP 769 |
14.88 |
| 2026-04-03 12:00 |
00:08:41.85 |
+01:23:29.8 |
HIP 769 |
14.55 |
| 2026-04-04 00:00 |
00:08:44.28 |
+01:23:45.2 |
HIP 769 |
14.23 |
| 2026-04-04 12:00 |
00:08:46.70 |
+01:24:00.6 |
HIP 769 |
13.94 |
| 2026-04-05 00:00 |
00:08:49.13 |
+01:24:15.9 |
HIP 769 |
13.68 |
| 2026-04-05 12:00 |
00:08:51.54 |
+01:24:31.2 |
HIP 769 |
13.44 |
| 2026-04-06 00:00 |
00:08:53.96 |
+01:24:46.6 |
HIP 769 |
13.24 |
| 2026-04-06 12:00 |
00:08:56.36 |
+01:25:01.8 |
HIP 769 |
13.06 |
| 2026-04-07 00:00 |
00:08:58.77 |
+01:25:17.1 |
HIP 769 |
12.91 |
| 2026-04-07 12:00 |
00:09:01.16 |
+01:25:32.3 |
HIP 769 |
12.80 |
| 2026-04-08 00:00 |
00:09:03.56 |
+01:25:47.5 |
HIP 769 |
12.72 |
| 2026-04-08 12:00 |
00:09:05.94 |
+01:26:02.6 |
HIP 769 |
12.67 |
| 2026-04-09 00:00 |
00:09:08.33 |
+01:26:17.7 |
HIP 769 |
12.65 |
| 2026-04-09 12:00 |
00:09:10.70 |
+01:26:32.8 |
HIP 769 |
12.67 |
| 2026-04-10 00:00 |
00:09:13.07 |
+01:26:47.9 |
HIP 769 |
12.72 |
| 2026-04-10 12:00 |
00:09:15.43 |
+01:27:02.9 |
HIP 769 |
12.80 |
| 2026-04-11 00:00 |
00:09:17.79 |
+01:27:17.9 |
HIP 769 |
12.91 |
| 2026-04-11 12:00 |
00:09:20.14 |
+01:27:32.8 |
HIP 769 |
13.05 |
| 2026-04-12 00:00 |
00:09:22.49 |
+01:27:47.7 |
HIP 769 |
13.23 |
| 2026-04-12 12:00 |
00:09:24.83 |
+01:28:02.5 |
HIP 769 |
13.42 |
| 2026-04-13 00:00 |
00:09:27.16 |
+01:28:17.4 |
HIP 769 |
13.65 |
| 2026-04-13 12:00 |
00:09:29.48 |
+01:28:32.1 |
HIP 769 |
13.90 |
| 2026-04-14 00:00 |
00:09:31.80 |
+01:28:46.8 |
HIP 769 |
14.17 |
| 2026-04-14 12:00 |
00:09:34.11 |
+01:29:01.5 |
HIP 769 |
14.46 |
| 2026-04-15 00:00 |
00:09:36.41 |
+01:29:16.2 |
HIP 769 |
14.78 |
| 2026-04-15 12:00 |
00:09:38.70 |
+01:29:30.7 |
HIP 769 |
15.11 |
| 2026-04-16 00:00 |
00:09:40.99 |
+01:29:45.3 |
HIP 769 |
15.46 |