| 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) |
| 2026-05-12 00:00 |
13:11:49.26 |
-27:40:59.0 |
HIP 64436 |
8.03 |
| 2026-05-12 12:00 |
13:11:46.84 |
-27:40:37.9 |
HIP 64436 |
8.46 |
| 2026-05-13 00:00 |
13:11:44.43 |
-27:40:16.8 |
HIP 64436 |
8.90 |
| 2026-05-13 12:00 |
13:11:42.03 |
-27:39:55.7 |
HIP 64436 |
9.37 |
| 2026-05-14 00:00 |
13:11:39.64 |
-27:39:34.5 |
HIP 64436 |
9.85 |
| 2026-05-14 12:00 |
13:11:37.27 |
-27:39:13.3 |
HIP 64436 |
10.34 |
| 2026-05-15 00:00 |
13:11:34.91 |
-27:38:52.1 |
HIP 64436 |
10.85 |
| 2026-05-15 12:00 |
13:11:32.57 |
-27:38:30.9 |
HIP 64436 |
11.37 |
| 2026-05-16 00:00 |
13:11:30.24 |
-27:38:09.6 |
HIP 64436 |
11.89 |
| 2026-05-16 12:00 |
13:11:27.93 |
-27:37:48.4 |
HIP 64436 |
12.42 |
| 2026-05-17 00:00 |
13:11:25.63 |
-27:37:27.0 |
HIP 64436 |
12.95 |
| 2026-05-17 12:00 |
13:11:23.34 |
-27:37:05.7 |
HIP 64436 |
13.49 |
| 2026-05-18 00:00 |
13:11:21.07 |
-27:36:44.4 |
HIP 64436 |
14.04 |
| 2026-05-18 12:00 |
13:11:18.82 |
-27:36:23.0 |
HIP 64436 |
14.58 |
| 2026-05-19 00:00 |
13:11:16.58 |
-27:36:01.7 |
HIP 64436 |
15.13 |
| 2026-05-19 12:00 |
13:11:14.35 |
-27:35:40.3 |
HIP 64436 |
15.68 |
| 2026-05-20 00:00 |
13:11:12.14 |
-27:35:18.9 |
HIP 64436 |
16.23 |
| 2026-05-20 12:00 |
13:11:09.95 |
-27:34:57.5 |
HIP 64436 |
16.78 |
| 2026-05-21 00:00 |
13:11:07.78 |
-27:34:36.1 |
HIP 64436 |
17.33 |
| 2026-05-21 12:00 |
13:11:05.61 |
-27:34:14.7 |
HIP 64436 |
17.88 |
| 2026-05-22 00:00 |
13:11:03.47 |
-27:33:53.2 |
HIP 64436 |
18.43 |
| 2026-05-22 12:00 |
13:11:01.34 |
-27:33:31.8 |
HIP 64436 |
18.97 |
| 2026-05-23 00:00 |
13:10:59.23 |
-27:33:10.4 |
HIP 64436 |
19.52 |
| 2026-05-23 12:00 |
13:10:57.13 |
-27:32:49.0 |
HIP 64436 |
20.07 |
| 2026-05-24 00:00 |
13:10:55.05 |
-27:32:27.6 |
HIP 64436 |
20.61 |
| 2026-05-24 12:00 |
13:10:52.99 |
-27:32:06.1 |
HIP 64436 |
21.16 |
| 2026-05-25 00:00 |
13:10:50.95 |
-27:31:44.7 |
HIP 64436 |
21.70 |
| 2026-05-25 12:00 |
13:10:48.92 |
-27:31:23.3 |
HIP 64436 |
22.24 |
| 2026-05-26 00:00 |
13:10:46.91 |
-27:31:01.9 |
HIP 64436 |
22.78 |
| 2026-05-26 12:00 |
13:10:44.92 |
-27:30:40.5 |
HIP 64193 |
22.68 |
| 2026-05-27 00:00 |
13:10:42.94 |
-27:30:19.2 |
HIP 64193 |
22.53 |
| 2026-05-27 12:00 |
13:10:40.98 |
-27:29:57.8 |
HIP 64193 |
22.40 |
| 2026-05-28 00:00 |
13:10:39.04 |
-27:29:36.4 |
HIP 64193 |
22.29 |
| 2026-05-28 12:00 |
13:10:37.12 |
-27:29:15.1 |
HIP 64193 |
22.19 |
| 2026-05-29 00:00 |
13:10:35.21 |
-27:28:53.8 |
HIP 64193 |
22.11 |
| 2026-05-29 12:00 |
13:10:33.33 |
-27:28:32.5 |
HIP 64193 |
22.04 |
| 2026-05-30 00:00 |
13:10:31.46 |
-27:28:11.2 |
HIP 64193 |
21.99 |
| 2026-05-30 12:00 |
13:10:29.61 |
-27:27:49.9 |
HIP 64193 |
21.96 |
| 2026-05-31 00:00 |
13:10:27.78 |
-27:27:28.7 |
HIP 64193 |
21.94 |
| 2026-05-31 12:00 |
13:10:25.96 |
-27:27:07.5 |
HIP 64193 |
21.93 |
| 2026-06-01 00:00 |
13:10:24.17 |
-27:26:46.3 |
HIP 64193 |
21.95 |
| 2026-06-01 12:00 |
13:10:22.39 |
-27:26:25.1 |
HIP 64193 |
21.97 |
| 2026-06-02 00:00 |
13:10:20.63 |
-27:26:04.0 |
HIP 64193 |
22.02 |