I'm reading now that the James Webb observatory will be at L2 point. Is possible in any way to look at this point from here in earth?
I mean... given my LAT and LON here what is the best time to have a sight line? Is near what constelation?
I read it is at "straight behind earth from sun point of view" but I have no idea what it means from my rotating POV.
If you can give me an example, I'm at -22.8885366,-43.104668.
Thanks.
If it can help (https://www.spaceweather.com/):
... so I tried the site and ...
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Revised: Aug 29, 2013 SEMB-L2 32
(Sun & Earth-Moon Barycenter Lagrange 2)
#1) The Sun & Earth-Moon Barycenter Lagrange-2 (L2) point is a location
where the Earth's gravitational field partially counters that of the
Sun.
#2) This L2 point is about 1.5 million km (~900,000 miles) away from the
Earth, opposite the direction of the Sun, or slightly less than one
percent of the Earth-Sun distance (four times the distance from Earth
to the Moon)
#3) L2 has been selected as the location of the next generation James Webb
Space Telescope, was used by the Genesis spacecraft on the return to
Earth, and is (or will be) used for WMAP, Herschel, and Planck
spacecraft.
Time-span available: 1900-Jan-01 to 2151-Jan-01
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Ephemeris / WWW_USER Wed Dec 29 18:42:20 2021 Pasadena, USA / Horizons
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Target body name: SEMB-L2 (32) {source: Sun-EMB_L2}
Center body name: Earth (399) {source: DE441}
Center-site name: (user defined site below)
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Start time : A.D. 2021-Dec-30 00:00:00.0000 UT
Stop time : A.D. 2021-Dec-31 00:00:00.0000 UT
Step-size : 1440 minutes
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Target pole/equ : No model available
Target radii : (unavailable)
Center geodetic : 316.895332,-22.888537,0.0100000 {E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: 316.895332,5878.92988,-2465.356 {E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : ITRF93 {East-longitude positive}
Center radii : 6378.1 x 6378.1 x 6356.8 km {Equator, meridian, pole}
Target primary : (Undefined)
Vis. interferer : MOON (R_eq= 1737.400) km {source: DE441}
Rel. light bend : Sun, EARTH {source: DE441}
Rel. lght bnd GM: 1.3271E+11, 3.9860E+05 km^3/s^2
Atmos refraction: NO (AIRLESS)
RA format : HMS
Time format : CAL
EOP file : eop.211228.p220323
EOP coverage : DATA-BASED 1962-JAN-20 TO 2021-DEC-28. PREDICTS-> 2022-MAR-22
Units conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s
Table cut-offs 1: Elevation (-90.0deg=NO ),Airmass (>38.000=NO), Daylight (NO )
Table cut-offs 2: Solar elongation ( 0.0,180.0=NO ),Local Hour Angle( 0.0=NO )
Table cut-offs 3: RA/DEC angular rate ( 0.0=NO )
******************************************************************************************************************************************************************************
Date__(UT)__HR:MN R.A._____(ICRF)_____DEC APmag S-brt delta deldot S-O-T /r S-T-O Sky_motion Sky_mot_PA RelVel-ANG Lun_Sky_Brt sky_SNR
******************************************************************************************************************************************************************************
$$SOE
2021-Dec-30 00:00 06 36 55.95 +23 19 55.7 n.a. n.a. 0.00987312593538 -0.2824505 179.6621 /L 0.3347 0.8202458 352.89131 -70.88475 n.a. n.a.
2021-Dec-31 00:00 06 41 13.66 +23 15 44.7 n.a. n.a. 0.00986809386682 -0.2810705 179.6899 /L 0.3071 0.8042847 351.62780 -71.15373 n.a. n.a.
$$EOE
******************************************************************************************************************************************************************************
... but I have no idea how to read these informations ...
I think the answer is here:
$$SOE
2021-Dec-30 00:00 06 36 55.95 +23 19 55.7 n.a. n.a. 0.00987312593538 -0.2824505 179.6621 /L 0.3347 0.8202458 352.89131 -70.88475 n.a. n.a.
2021-Dec-31 00:00 06 41 13.66 +23 15 44.7 n.a. n.a. 0.00986809386682 -0.2810705 179.6899 /L 0.3071 0.8042847 351.62780 -71.15373 n.a. n.a.
$$EOE
and I need to take R.A. and DEC. May I use this post ( from myself ) to "project" the L2 on earth surface...
Can someone correct me? What is "RA" and "DEC" from the data above?