C/1988 Y1 (Yanaka)
| 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
$$
M_a = (13.085 + 5.713\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.085 |
| n |
5.713 |
| 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) |
| 2026-02-03 00:00 |
09:27:36.46 |
-63:18:37.9 |
HIP 46481 |
9.82 |
| 2026-02-03 12:00 |
09:27:32.37 |
-63:18:39.4 |
HIP 46481 |
10.21 |
| 2026-02-04 00:00 |
09:27:28.29 |
-63:18:40.6 |
HIP 46481 |
10.60 |
| 2026-02-04 12:00 |
09:27:24.20 |
-63:18:41.5 |
HIP 46481 |
11.00 |
| 2026-02-05 00:00 |
09:27:20.11 |
-63:18:42.2 |
HIP 46481 |
11.40 |
| 2026-02-05 12:00 |
09:27:16.01 |
-63:18:42.6 |
HIP 46481 |
11.80 |
| 2026-02-06 00:00 |
09:27:11.91 |
-63:18:42.8 |
HIP 46481 |
12.20 |
| 2026-02-06 12:00 |
09:27:07.82 |
-63:18:42.7 |
HIP 46481 |
12.61 |
| 2026-02-07 00:00 |
09:27:03.71 |
-63:18:42.3 |
HIP 46481 |
13.01 |
| 2026-02-07 12:00 |
09:26:59.61 |
-63:18:41.7 |
HIP 46481 |
13.42 |
| 2026-02-08 00:00 |
09:26:55.51 |
-63:18:40.9 |
HIP 46481 |
13.83 |
| 2026-02-08 12:00 |
09:26:51.41 |
-63:18:39.8 |
HIP 46481 |
14.25 |
| 2026-02-09 00:00 |
09:26:47.30 |
-63:18:38.4 |
HIP 46481 |
14.66 |
| 2026-02-09 12:00 |
09:26:43.20 |
-63:18:36.8 |
HIP 46481 |
15.07 |
| 2026-02-10 00:00 |
09:26:39.10 |
-63:18:34.9 |
HIP 46481 |
15.49 |
| 2026-02-10 12:00 |
09:26:35.00 |
-63:18:32.7 |
HIP 46481 |
15.91 |
| 2026-02-11 00:00 |
09:26:30.90 |
-63:18:30.3 |
HIP 46481 |
16.32 |
| 2026-02-11 12:00 |
09:26:26.80 |
-63:18:27.7 |
HIP 46481 |
16.74 |
| 2026-02-12 00:00 |
09:26:22.70 |
-63:18:24.8 |
HIP 46481 |
17.16 |
| 2026-02-12 12:00 |
09:26:18.60 |
-63:18:21.6 |
HIP 46481 |
17.58 |
| 2026-02-13 00:00 |
09:26:14.51 |
-63:18:18.2 |
HIP 46481 |
18.00 |
| 2026-02-13 12:00 |
09:26:10.42 |
-63:18:14.5 |
HIP 46481 |
18.42 |
| 2026-02-14 00:00 |
09:26:06.34 |
-63:18:10.6 |
HIP 46481 |
18.85 |
| 2026-02-14 12:00 |
09:26:02.26 |
-63:18:06.4 |
HIP 46481 |
19.27 |
| 2026-02-15 00:00 |
09:25:58.18 |
-63:18:02.0 |
HIP 46481 |
19.69 |
| 2026-02-15 12:00 |
09:25:54.10 |
-63:17:57.3 |
HIP 46481 |
20.11 |
| 2026-02-16 00:00 |
09:25:50.04 |
-63:17:52.4 |
HIP 46481 |
20.54 |
| 2026-02-16 12:00 |
09:25:45.97 |
-63:17:47.2 |
HIP 46481 |
20.96 |
| 2026-02-17 00:00 |
09:25:41.91 |
-63:17:41.7 |
HIP 46481 |
21.38 |
| 2026-02-17 12:00 |
09:25:37.86 |
-63:17:36.0 |
HIP 46481 |
21.81 |
| 2026-02-18 00:00 |
09:25:33.82 |
-63:17:30.1 |
HIP 46481 |
22.23 |
| 2026-02-18 12:00 |
09:25:29.78 |
-63:17:23.9 |
HIP 46481 |
22.66 |
| 2026-02-19 00:00 |
09:25:25.74 |
-63:17:17.5 |
HIP 46481 |
23.08 |
| 2026-02-19 12:00 |
09:25:21.72 |
-63:17:10.8 |
HIP 46481 |
23.50 |
| 2026-02-20 00:00 |
09:25:17.70 |
-63:17:03.8 |
HIP 46481 |
23.93 |
| 2026-02-20 12:00 |
09:25:13.69 |
-63:16:56.6 |
HIP 46481 |
24.35 |
| 2026-02-21 00:00 |
09:25:09.69 |
-63:16:49.2 |
HIP 46481 |
24.78 |
| 2026-02-21 12:00 |
09:25:05.70 |
-63:16:41.5 |
HIP 45923 |
25.14 |
| 2026-02-22 00:00 |
09:25:01.72 |
-63:16:33.6 |
HIP 45923 |
24.68 |
| 2026-02-22 12:00 |
09:24:57.74 |
-63:16:25.4 |
HIP 45923 |
24.23 |
| 2026-02-23 00:00 |
09:24:53.78 |
-63:16:17.0 |
HIP 45923 |
23.77 |
| 2026-02-23 12:00 |
09:24:49.83 |
-63:16:08.3 |
HIP 45923 |
23.31 |
| 2026-02-24 00:00 |
09:24:45.88 |
-63:15:59.5 |
HIP 45923 |
22.85 |