| 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) |
| 2026-07-29 00:00 |
13:09:20.13 |
-26:54:18.0 |
HIP 64343 |
31.03 |
| 2026-07-29 12:00 |
13:09:20.87 |
-26:54:08.0 |
HIP 64343 |
30.80 |
| 2026-07-30 00:00 |
13:09:21.63 |
-26:53:58.2 |
HIP 64343 |
30.58 |
| 2026-07-30 12:00 |
13:09:22.41 |
-26:53:48.5 |
HIP 64343 |
30.35 |
| 2026-07-31 00:00 |
13:09:23.21 |
-26:53:39.0 |
HIP 64343 |
30.11 |
| 2026-07-31 12:00 |
13:09:24.03 |
-26:53:29.6 |
HIP 64343 |
29.88 |
| 2026-08-01 00:00 |
13:09:24.87 |
-26:53:20.3 |
HIP 64343 |
29.64 |
| 2026-08-01 12:00 |
13:09:25.73 |
-26:53:11.2 |
HIP 64343 |
29.40 |
| 2026-08-02 00:00 |
13:09:26.61 |
-26:53:02.3 |
HIP 64343 |
29.16 |
| 2026-08-02 12:00 |
13:09:27.51 |
-26:52:53.5 |
HIP 64343 |
28.91 |
| 2026-08-03 00:00 |
13:09:28.44 |
-26:52:44.8 |
HIP 64343 |
28.66 |
| 2026-08-03 12:00 |
13:09:29.38 |
-26:52:36.3 |
HIP 64343 |
28.41 |
| 2026-08-04 00:00 |
13:09:30.34 |
-26:52:28.0 |
HIP 64343 |
28.15 |
| 2026-08-04 12:00 |
13:09:31.33 |
-26:52:19.8 |
HIP 64343 |
27.89 |
| 2026-08-05 00:00 |
13:09:32.33 |
-26:52:11.7 |
HIP 64343 |
27.63 |
| 2026-08-05 12:00 |
13:09:33.35 |
-26:52:03.8 |
HIP 64343 |
27.37 |
| 2026-08-06 00:00 |
13:09:34.40 |
-26:51:56.1 |
HIP 64343 |
27.10 |
| 2026-08-06 12:00 |
13:09:35.46 |
-26:51:48.5 |
HIP 64343 |
26.84 |
| 2026-08-07 00:00 |
13:09:36.54 |
-26:51:41.0 |
HIP 64343 |
26.56 |
| 2026-08-07 12:00 |
13:09:37.65 |
-26:51:33.7 |
HIP 64343 |
26.29 |
| 2026-08-08 00:00 |
13:09:38.77 |
-26:51:26.6 |
HIP 64343 |
26.01 |
| 2026-08-08 12:00 |
13:09:39.91 |
-26:51:19.6 |
HIP 64343 |
25.73 |
| 2026-08-09 00:00 |
13:09:41.08 |
-26:51:12.8 |
HIP 64343 |
25.45 |
| 2026-08-09 12:00 |
13:09:42.26 |
-26:51:06.1 |
HIP 64343 |
25.17 |
| 2026-08-10 00:00 |
13:09:43.46 |
-26:50:59.6 |
HIP 64343 |
24.88 |
| 2026-08-10 12:00 |
13:09:44.68 |
-26:50:53.3 |
HIP 64343 |
24.59 |
| 2026-08-11 00:00 |
13:09:45.92 |
-26:50:47.1 |
HIP 64343 |
24.30 |
| 2026-08-11 12:00 |
13:09:47.18 |
-26:50:41.0 |
HIP 64343 |
24.00 |
| 2026-08-12 00:00 |
13:09:48.46 |
-26:50:35.1 |
HIP 64343 |
23.70 |
| 2026-08-12 12:00 |
13:09:49.75 |
-26:50:29.4 |
HIP 64343 |
23.40 |
| 2026-08-13 00:00 |
13:09:51.07 |
-26:50:23.8 |
HIP 64343 |
23.10 |
| 2026-08-13 12:00 |
13:09:52.40 |
-26:50:18.4 |
HIP 64343 |
22.80 |
| 2026-08-14 00:00 |
13:09:53.76 |
-26:50:13.1 |
HIP 64343 |
22.49 |
| 2026-08-14 12:00 |
13:09:55.13 |
-26:50:08.0 |
HIP 64343 |
22.18 |
| 2026-08-15 00:00 |
13:09:56.52 |
-26:50:03.1 |
HIP 64343 |
21.87 |
| 2026-08-15 12:00 |
13:09:57.93 |
-26:49:58.3 |
HIP 64343 |
21.56 |
| 2026-08-16 00:00 |
13:09:59.35 |
-26:49:53.6 |
HIP 64343 |
21.25 |
| 2026-08-16 12:00 |
13:10:00.80 |
-26:49:49.2 |
HIP 64343 |
20.93 |
| 2026-08-17 00:00 |
13:10:02.26 |
-26:49:44.8 |
HIP 64343 |
20.62 |
| 2026-08-17 12:00 |
13:10:03.74 |
-26:49:40.7 |
HIP 64343 |
20.30 |
| 2026-08-18 00:00 |
13:10:05.24 |
-26:49:36.7 |
HIP 64343 |
19.98 |
| 2026-08-18 12:00 |
13:10:06.75 |
-26:49:32.8 |
HIP 64343 |
19.66 |
| 2026-08-19 00:00 |
13:10:08.28 |
-26:49:29.1 |
HIP 64343 |
19.33 |