메타데이터

항목	값
Designation	8P/Tuttle
Type	P
Perihelion (tp_cal, UTC)	2008-01-27T00:25:56.539200Z
Orbit solution date (soln_date, UTC)	2022-05-02T08:47:13Z
Obs used	1768
NEO	Yes
M1	14.600
K1	4.500
PC	-

Osculating 궤도요소

항목	값
Epoch (epoch_cal, TDB)	2008-08-23.0000000
e	0.81978762
q (au)	1.027263
a (au)	5.700291
i (deg)	54.981969
Ω (om, deg)	270.342162
ω (w, deg)	207.511518
M (ma, deg)	15.134474

밝기

산란 + 전체 선형

$$ M_a = (9.885 + 4.854\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

모델 상수

항목	값
H0	9.885
n	4.854
gf	1.000
gb	-0.500
k	1.000
δ90	10.000

파라미터	기호	범위	설명
태양·지구거리 1 AU에서의 절대등급	H0	-5 to 20	혜성의 고유 밝기
광도 기울기 파라미터	n	2 to 6	태양거리 변화에 따른 밝기 변화율
전방 산란 비대칭 계수	gf	0.8 to 1	전방 산란의 강도
후방 산란 비대칭 계수	gb	-1 to -0.5	후방 산란의 강도
분할 계수	k	0.8 to 1	전·후방 산란 기여도 비율
먼지/가스 밝기 비	δ90	1 to 10	코마에서 먼지 산란 대비 가스 방출의 상대 기여

참고: EPSC-DPS2025-160

잔차 (구간 선형)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

시작일 (UTC)	끝 (UTC)	a	b
2020-06-21	2021-10-15	-12.4684	-1.024
2021-10-15	2021-08-27	+7.6790	-2.670
2021-08-27	2022-03-19	-2.4327	+1.020

log10 r = log10(태양거리/AU), Δ = 지구거리(AU)

천체력

Date/Time (UTC)	RA (J2000)	Dec (J2000)	Nearest HIP	Dist from HIP (arcmin)
2026-09-20 00:00	18:21:29.82	-07:21:34.7	HIP 90030	13.15
2026-09-20 12:00	18:21:29.33	-07:22:04.0	HIP 90030	12.94
2026-09-21 00:00	18:21:28.95	-07:22:33.3	HIP 90030	12.73
2026-09-21 12:00	18:21:28.67	-07:23:02.5	HIP 90030	12.51
2026-09-22 00:00	18:21:28.50	-07:23:31.6	HIP 90030	12.29
2026-09-22 12:00	18:21:28.43	-07:24:00.7	HIP 90030	12.06
2026-09-23 00:00	18:21:28.47	-07:24:29.7	HIP 90030	11.82
2026-09-23 12:00	18:21:28.60	-07:24:58.6	HIP 90030	11.58
2026-09-24 00:00	18:21:28.84	-07:25:27.5	HIP 90030	11.32
2026-09-24 12:00	18:21:29.19	-07:25:56.3	HIP 90030	11.06
2026-09-25 00:00	18:21:29.63	-07:26:25.0	HIP 90030	10.80
2026-09-25 12:00	18:21:30.18	-07:26:53.6	HIP 90030	10.52
2026-09-26 00:00	18:21:30.83	-07:27:22.2	HIP 90030	10.24
2026-09-26 12:00	18:21:31.58	-07:27:50.6	HIP 90030	9.95
2026-09-27 00:00	18:21:32.43	-07:28:19.0	HIP 90030	9.65
2026-09-27 12:00	18:21:33.38	-07:28:47.2	HIP 90030	9.35
2026-09-28 00:00	18:21:34.44	-07:29:15.4	HIP 90030	9.04
2026-09-28 12:00	18:21:35.60	-07:29:43.5	HIP 90030	8.73
2026-09-29 00:00	18:21:36.85	-07:30:11.4	HIP 90030	8.42
2026-09-29 12:00	18:21:38.21	-07:30:39.3	HIP 90030	8.12
2026-09-30 00:00	18:21:39.66	-07:31:07.0	HIP 90030	7.81
2026-09-30 12:00	18:21:41.22	-07:31:34.6	HIP 90030	7.52
2026-10-01 00:00	18:21:42.88	-07:32:02.1	HIP 90030	7.24
2026-10-01 12:00	18:21:44.63	-07:32:29.5	HIP 90030	6.98
2026-10-02 00:00	18:21:46.49	-07:32:56.8	HIP 90030	6.75
2026-10-02 12:00	18:21:48.44	-07:33:23.9	HIP 90030	6.55
2026-10-03 00:00	18:21:50.50	-07:33:50.9	HIP 90030	6.39
2026-10-03 12:00	18:21:52.65	-07:34:17.8	HIP 90030	6.28
2026-10-04 00:00	18:21:54.90	-07:34:44.6	HIP 90030	6.23
2026-10-04 12:00	18:21:57.25	-07:35:11.2	HIP 90030	6.24
2026-10-05 00:00	18:21:59.70	-07:35:37.6	HIP 90030	6.33
2026-10-05 12:00	18:22:02.24	-07:36:03.9	HIP 90030	6.50
2026-10-06 00:00	18:22:04.89	-07:36:30.1	HIP 90030	6.74
2026-10-06 12:00	18:22:07.63	-07:36:56.1	HIP 90030	7.05
2026-10-07 00:00	18:22:10.46	-07:37:21.9	HIP 90030	7.44
2026-10-07 12:00	18:22:13.40	-07:37:47.6	HIP 90030	7.89
2026-10-08 00:00	18:22:16.43	-07:38:13.1	HIP 90030	8.41
2026-10-08 12:00	18:22:19.55	-07:38:38.5	HIP 90030	8.98
2026-10-09 00:00	18:22:22.78	-07:39:03.7	HIP 90030	9.60
2026-10-09 12:00	18:22:26.09	-07:39:28.7	HIP 90030	10.28
2026-10-10 00:00	18:22:29.51	-07:39:53.5	HIP 90030	10.99
2026-10-10 12:00	18:22:33.01	-07:40:18.2	HIP 90030	11.74
2026-10-11 00:00	18:22:36.61	-07:40:42.6	HIP 90030	12.54