| Parameter |
Value |
| Designation |
C/1988 Y1 (Yanaka) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1988-12-11T15:40:33.395520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:36Z |
| Obs used |
56 |
| NEO |
- |
| M1 |
12.800 |
| K1 |
15.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1989-01-12.0000000 |
| e |
1.00000000 |
| q (au) |
0.427814 |
| a (au) |
- |
| i (deg) |
71.010955 |
| Ω (om, deg) |
315.523025 |
| ω (w, deg) |
88.122151 |
| M (ma, deg) |
- |
Magnitude
Scatter + Global Linear
$$
M_a = (13.086 + 5.655\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.086 |
| n |
5.655 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
1.000 |
| 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 |
09:21:19.47 |
-63:00:27.6 |
HIP 45923 |
5.37 |
| 2026-03-26 12:00 |
09:21:16.71 |
-63:00:06.3 |
HIP 45923 |
5.85 |
| 2026-03-27 00:00 |
09:21:13.97 |
-62:59:44.9 |
HIP 45923 |
6.32 |
| 2026-03-27 12:00 |
09:21:11.25 |
-62:59:23.3 |
HIP 45923 |
6.79 |
| 2026-03-28 00:00 |
09:21:08.57 |
-62:59:01.5 |
HIP 45923 |
7.27 |
| 2026-03-28 12:00 |
09:21:05.91 |
-62:58:39.6 |
HIP 45923 |
7.74 |
| 2026-03-29 00:00 |
09:21:03.28 |
-62:58:17.5 |
HIP 45923 |
8.21 |
| 2026-03-29 12:00 |
09:21:00.68 |
-62:57:55.3 |
HIP 45923 |
8.69 |
| 2026-03-30 00:00 |
09:20:58.11 |
-62:57:33.0 |
HIP 45923 |
9.16 |
| 2026-03-30 12:00 |
09:20:55.56 |
-62:57:10.5 |
HIP 45923 |
9.63 |
| 2026-03-31 00:00 |
09:20:53.04 |
-62:56:47.8 |
HIP 45923 |
10.11 |
| 2026-03-31 12:00 |
09:20:50.55 |
-62:56:25.1 |
HIP 45923 |
10.58 |
| 2026-04-01 00:00 |
09:20:48.09 |
-62:56:02.2 |
HIP 45923 |
11.05 |
| 2026-04-01 12:00 |
09:20:45.66 |
-62:55:39.1 |
HIP 45923 |
11.52 |
| 2026-04-02 00:00 |
09:20:43.26 |
-62:55:16.0 |
HIP 45923 |
11.99 |
| 2026-04-02 12:00 |
09:20:40.89 |
-62:54:52.7 |
HIP 45923 |
12.47 |
| 2026-04-03 00:00 |
09:20:38.54 |
-62:54:29.2 |
HIP 45923 |
12.94 |
| 2026-04-03 12:00 |
09:20:36.23 |
-62:54:05.7 |
HIP 45729 |
13.30 |
| 2026-04-04 00:00 |
09:20:33.94 |
-62:53:42.0 |
HIP 45729 |
12.83 |
| 2026-04-04 12:00 |
09:20:31.68 |
-62:53:18.2 |
HIP 45729 |
12.36 |
| 2026-04-05 00:00 |
09:20:29.46 |
-62:52:54.3 |
HIP 45729 |
11.89 |
| 2026-04-05 12:00 |
09:20:27.26 |
-62:52:30.2 |
HIP 45729 |
11.43 |
| 2026-04-06 00:00 |
09:20:25.09 |
-62:52:06.1 |
HIP 45729 |
10.96 |
| 2026-04-06 12:00 |
09:20:22.96 |
-62:51:41.8 |
HIP 45729 |
10.50 |
| 2026-04-07 00:00 |
09:20:20.85 |
-62:51:17.4 |
HIP 45729 |
10.04 |
| 2026-04-07 12:00 |
09:20:18.77 |
-62:50:52.9 |
HIP 45729 |
9.58 |
| 2026-04-08 00:00 |
09:20:16.73 |
-62:50:28.3 |
HIP 45729 |
9.12 |
| 2026-04-08 12:00 |
09:20:14.71 |
-62:50:03.6 |
HIP 45729 |
8.67 |
| 2026-04-09 00:00 |
09:20:12.73 |
-62:49:38.7 |
HIP 45729 |
8.22 |
| 2026-04-09 12:00 |
09:20:10.78 |
-62:49:13.8 |
HIP 45729 |
7.77 |
| 2026-04-10 00:00 |
09:20:08.85 |
-62:48:48.8 |
HIP 45729 |
7.33 |
| 2026-04-10 12:00 |
09:20:06.96 |
-62:48:23.6 |
HIP 45729 |
6.89 |
| 2026-04-11 00:00 |
09:20:05.10 |
-62:47:58.4 |
HIP 45729 |
6.46 |
| 2026-04-11 12:00 |
09:20:03.28 |
-62:47:33.1 |
HIP 45729 |
6.04 |
| 2026-04-12 00:00 |
09:20:01.48 |
-62:47:07.6 |
HIP 45729 |
5.63 |
| 2026-04-12 12:00 |
09:19:59.72 |
-62:46:42.1 |
HIP 45729 |
5.23 |
| 2026-04-13 00:00 |
09:19:57.98 |
-62:46:16.5 |
HIP 45729 |
4.85 |
| 2026-04-13 12:00 |
09:19:56.28 |
-62:45:50.8 |
HIP 45729 |
4.48 |
| 2026-04-14 00:00 |
09:19:54.61 |
-62:45:25.0 |
HIP 45729 |
4.14 |
| 2026-04-14 12:00 |
09:19:52.98 |
-62:44:59.1 |
HIP 45729 |
3.83 |
| 2026-04-15 00:00 |
09:19:51.37 |
-62:44:33.2 |
HIP 45729 |
3.56 |
| 2026-04-15 12:00 |
09:19:49.80 |
-62:44:07.2 |
HIP 45729 |
3.33 |
| 2026-04-16 00:00 |
09:19:48.26 |
-62:43:41.1 |
HIP 45729 |
3.17 |