| Parameter |
Value |
| Designation |
C/1999 Y1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2001-03-24T01:09:17.948160Z |
| Orbit solution date (soln_date, UTC) |
2022-04-30T03:12:26Z |
| Obs used |
833 |
| NEO |
- |
| M1 |
7.300 |
| K1 |
8.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2000-09-17.0000000 |
| e |
1.00085745 |
| q (au) |
3.091379 |
| a (au) |
-3605.302714 |
| i (deg) |
134.795873 |
| Ω (om, deg) |
188.877122 |
| ω (w, deg) |
184.264817 |
| M (ma, deg) |
-0.000856 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.335 + 5.484\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.335 |
| n |
5.484 |
| gf |
1.000 |
| gb |
-0.641 |
| k |
0.800 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1999-10-29 |
2000-02-28 |
+21.2209 |
-14.967 |
| 2000-02-28 |
2001-02-21 |
-6.9073 |
+3.809 |
| 2001-05-31 |
2003-07-19 |
-4.9693 |
+2.340 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
13:12:16.66 |
-26:50:54.0 |
HIP 64343 |
17.05 |
| 2026-09-20 12:00 |
13:12:19.04 |
-26:51:00.1 |
HIP 64343 |
17.51 |
| 2026-09-21 00:00 |
13:12:21.42 |
-26:51:06.4 |
HIP 64343 |
17.97 |
| 2026-09-21 12:00 |
13:12:23.82 |
-26:51:12.8 |
HIP 64343 |
18.44 |
| 2026-09-22 00:00 |
13:12:26.22 |
-26:51:19.4 |
HIP 64343 |
18.92 |
| 2026-09-22 12:00 |
13:12:28.63 |
-26:51:26.1 |
HIP 64343 |
19.41 |
| 2026-09-23 00:00 |
13:12:31.04 |
-26:51:32.9 |
HIP 64343 |
19.90 |
| 2026-09-23 12:00 |
13:12:33.47 |
-26:51:39.9 |
HIP 64343 |
20.40 |
| 2026-09-24 00:00 |
13:12:35.90 |
-26:51:47.0 |
HIP 64343 |
20.90 |
| 2026-09-24 12:00 |
13:12:38.34 |
-26:51:54.3 |
HIP 64343 |
21.40 |
| 2026-09-25 00:00 |
13:12:40.78 |
-26:52:01.6 |
HIP 64343 |
21.92 |
| 2026-09-25 12:00 |
13:12:43.23 |
-26:52:09.2 |
HIP 64343 |
22.43 |
| 2026-09-26 00:00 |
13:12:45.69 |
-26:52:16.8 |
HIP 64343 |
22.95 |
| 2026-09-26 12:00 |
13:12:48.15 |
-26:52:24.6 |
HIP 64343 |
23.48 |
| 2026-09-27 00:00 |
13:12:50.62 |
-26:52:32.5 |
HIP 64343 |
24.01 |
| 2026-09-27 12:00 |
13:12:53.09 |
-26:52:40.5 |
HIP 64343 |
24.54 |
| 2026-09-28 00:00 |
13:12:55.57 |
-26:52:48.7 |
HIP 64544 |
24.51 |
| 2026-09-28 12:00 |
13:12:58.06 |
-26:52:56.9 |
HIP 64544 |
24.39 |
| 2026-09-29 00:00 |
13:13:00.55 |
-26:53:05.4 |
HIP 64544 |
24.29 |
| 2026-09-29 12:00 |
13:13:03.05 |
-26:53:13.9 |
HIP 64544 |
24.19 |
| 2026-09-30 00:00 |
13:13:05.55 |
-26:53:22.6 |
HIP 64544 |
24.11 |
| 2026-09-30 12:00 |
13:13:08.05 |
-26:53:31.4 |
HIP 64544 |
24.05 |
| 2026-10-01 00:00 |
13:13:10.57 |
-26:53:40.3 |
HIP 64544 |
24.01 |
| 2026-10-01 12:00 |
13:13:13.08 |
-26:53:49.4 |
HIP 64544 |
23.97 |
| 2026-10-02 00:00 |
13:13:15.60 |
-26:53:58.5 |
HIP 64544 |
23.96 |
| 2026-10-02 12:00 |
13:13:18.13 |
-26:54:07.8 |
HIP 64544 |
23.96 |
| 2026-10-03 00:00 |
13:13:20.65 |
-26:54:17.2 |
HIP 64544 |
23.97 |
| 2026-10-03 12:00 |
13:13:23.19 |
-26:54:26.8 |
HIP 64544 |
24.01 |
| 2026-10-04 00:00 |
13:13:25.72 |
-26:54:36.5 |
HIP 64544 |
24.06 |
| 2026-10-04 12:00 |
13:13:28.26 |
-26:54:46.2 |
HIP 64544 |
24.12 |
| 2026-10-05 00:00 |
13:13:30.80 |
-26:54:56.1 |
HIP 64544 |
24.20 |
| 2026-10-05 12:00 |
13:13:33.35 |
-26:55:06.2 |
HIP 64544 |
24.30 |
| 2026-10-06 00:00 |
13:13:35.90 |
-26:55:16.3 |
HIP 64544 |
24.41 |
| 2026-10-06 12:00 |
13:13:38.45 |
-26:55:26.6 |
HIP 64544 |
24.54 |
| 2026-10-07 00:00 |
13:13:41.01 |
-26:55:37.0 |
HIP 64544 |
24.68 |
| 2026-10-07 12:00 |
13:13:43.56 |
-26:55:47.4 |
HIP 64544 |
24.84 |
| 2026-10-08 00:00 |
13:13:46.12 |
-26:55:58.1 |
HIP 64544 |
25.02 |
| 2026-10-08 12:00 |
13:13:48.68 |
-26:56:08.8 |
HIP 64544 |
25.21 |
| 2026-10-09 00:00 |
13:13:51.25 |
-26:56:19.6 |
HIP 64544 |
25.41 |
| 2026-10-09 12:00 |
13:13:53.81 |
-26:56:30.6 |
HIP 64544 |
25.63 |
| 2026-10-10 00:00 |
13:13:56.38 |
-26:56:41.6 |
HIP 64544 |
25.86 |
| 2026-10-10 12:00 |
13:13:58.94 |
-26:56:52.8 |
HIP 64544 |
26.11 |
| 2026-10-11 00:00 |
13:14:01.51 |
-26:57:04.1 |
HIP 64544 |
26.37 |