| 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) |
| 2026-03-26 00:00 |
13:16:08.38 |
-28:08:08.3 |
HIP 64772 |
6.02 |
| 2026-03-26 12:00 |
13:16:05.61 |
-28:07:56.5 |
HIP 64772 |
6.34 |
| 2026-03-27 00:00 |
13:16:02.83 |
-28:07:44.5 |
HIP 64772 |
6.71 |
| 2026-03-27 12:00 |
13:16:00.04 |
-28:07:32.4 |
HIP 64772 |
7.12 |
| 2026-03-28 00:00 |
13:15:57.25 |
-28:07:20.1 |
HIP 64772 |
7.56 |
| 2026-03-28 12:00 |
13:15:54.45 |
-28:07:07.6 |
HIP 64772 |
8.02 |
| 2026-03-29 00:00 |
13:15:51.64 |
-28:06:55.1 |
HIP 64772 |
8.52 |
| 2026-03-29 12:00 |
13:15:48.84 |
-28:06:42.3 |
HIP 64772 |
9.03 |
| 2026-03-30 00:00 |
13:15:46.02 |
-28:06:29.5 |
HIP 64772 |
9.56 |
| 2026-03-30 12:00 |
13:15:43.20 |
-28:06:16.4 |
HIP 64772 |
10.11 |
| 2026-03-31 00:00 |
13:15:40.38 |
-28:06:03.3 |
HIP 64772 |
10.67 |
| 2026-03-31 12:00 |
13:15:37.55 |
-28:05:50.0 |
HIP 64772 |
11.24 |
| 2026-04-01 00:00 |
13:15:34.72 |
-28:05:36.5 |
HIP 64772 |
11.82 |
| 2026-04-01 12:00 |
13:15:31.88 |
-28:05:23.0 |
HIP 64772 |
12.41 |
| 2026-04-02 00:00 |
13:15:29.04 |
-28:05:09.2 |
HIP 64772 |
13.01 |
| 2026-04-02 12:00 |
13:15:26.20 |
-28:04:55.4 |
HIP 64772 |
13.62 |
| 2026-04-03 00:00 |
13:15:23.36 |
-28:04:41.4 |
HIP 64772 |
14.23 |
| 2026-04-03 12:00 |
13:15:20.51 |
-28:04:27.2 |
HIP 64772 |
14.84 |
| 2026-04-04 00:00 |
13:15:17.66 |
-28:04:13.0 |
HIP 64772 |
15.47 |
| 2026-04-04 12:00 |
13:15:14.80 |
-28:03:58.6 |
HIP 64772 |
16.09 |
| 2026-04-05 00:00 |
13:15:11.94 |
-28:03:44.0 |
HIP 64772 |
16.72 |
| 2026-04-05 12:00 |
13:15:09.08 |
-28:03:29.3 |
HIP 64772 |
17.36 |
| 2026-04-06 00:00 |
13:15:06.22 |
-28:03:14.5 |
HIP 64772 |
18.00 |
| 2026-04-06 12:00 |
13:15:03.36 |
-28:02:59.6 |
HIP 64772 |
18.64 |
| 2026-04-07 00:00 |
13:15:00.50 |
-28:02:44.5 |
HIP 64772 |
19.29 |
| 2026-04-07 12:00 |
13:14:57.63 |
-28:02:29.3 |
HIP 64772 |
19.93 |
| 2026-04-08 00:00 |
13:14:54.76 |
-28:02:14.0 |
HIP 64772 |
20.58 |
| 2026-04-08 12:00 |
13:14:51.90 |
-28:01:58.5 |
HIP 64772 |
21.24 |
| 2026-04-09 00:00 |
13:14:49.03 |
-28:01:43.0 |
HIP 64772 |
21.89 |
| 2026-04-09 12:00 |
13:14:46.16 |
-28:01:27.3 |
HIP 64772 |
22.55 |
| 2026-04-10 00:00 |
13:14:43.29 |
-28:01:11.4 |
HIP 64772 |
23.21 |
| 2026-04-10 12:00 |
13:14:40.42 |
-28:00:55.5 |
HIP 64772 |
23.87 |
| 2026-04-11 00:00 |
13:14:37.55 |
-28:00:39.4 |
HIP 64772 |
24.53 |
| 2026-04-11 12:00 |
13:14:34.68 |
-28:00:23.2 |
HIP 64548 |
24.88 |
| 2026-04-12 00:00 |
13:14:31.82 |
-28:00:06.9 |
HIP 64548 |
24.37 |
| 2026-04-12 12:00 |
13:14:28.95 |
-27:59:50.4 |
HIP 64548 |
23.88 |
| 2026-04-13 00:00 |
13:14:26.08 |
-27:59:33.9 |
HIP 64548 |
23.38 |
| 2026-04-13 12:00 |
13:14:23.22 |
-27:59:17.2 |
HIP 64548 |
22.90 |
| 2026-04-14 00:00 |
13:14:20.36 |
-27:59:00.4 |
HIP 64548 |
22.43 |
| 2026-04-14 12:00 |
13:14:17.50 |
-27:58:43.5 |
HIP 64548 |
21.97 |
| 2026-04-15 00:00 |
13:14:14.64 |
-27:58:26.5 |
HIP 64548 |
21.51 |
| 2026-04-15 12:00 |
13:14:11.78 |
-27:58:09.4 |
HIP 64548 |
21.07 |
| 2026-04-16 00:00 |
13:14:08.93 |
-27:57:52.2 |
HIP 64548 |
20.64 |