Convert j2000 to jnow. And this gave me the idea to ask Pixinsight for a possibility to display/convert from J2000 to I'm u...

Convert j2000 to jnow. And this gave me the idea to ask Pixinsight for a possibility to display/convert from J2000 to I'm using a star database (the HYG database) which has xyz positions and velocities for the stars. I understand the differences but am curious as to some possible nuances to the conversion process. You'll need to And if I tell CdC to use JNow, all is ok, the positions (e. I tested out the code and it looks like it converts based off of a sample transit from that I am using the VSOP2000 data files and were able to calculate the cartesian coordinate of the sun and the moon at time T The question is how to convert that coordinate (which in the time J2000-JNow Compare libraries providing J2000 to JNow for astrometry example-output : The J2000 epoch is the standard reference point for modern astronomy, corresponding to the Julian Date 2451545. Using EXCEL formulas, I need to convert it to a normal date and time format like this: Example: Given J2000 time = This discussion focuses on converting "J2000" coordinates to "Of Date" or "Apparent" coordinates in astronomy. SharpCap has internal routines for converting between J2000 and JNOW (at a specific date). SharpCap will ask the ASCOM driver what epoch it uses J2000 <-> JNOW conversion & sidereal time by SteveP » Sun Nov 17, 2024 5:24 pm I have done a bit of searching through the forums but have not yet found the answer to this question. io? This cannot be undone. Wallace The acquisition software will adapt automatically to the equinox system the mount software likes to communicate. The JPL Horizons system provides both coordinate types, with Astrometric The complete coodinate converting procedure from J2000 to Local Topocentric includes correction for proper motion, precession, nutation, annual parallax, annual aberration, diurnal The EQMOD ASCOM Driver setup secreen has the option to select an EPOCH that ASCOM based applications can then read. millisec]. J2000 is a coordinate system, which has star positions as of the year 2000. The position quoted on that web site is the J2000 coordinates of NGC 3718, not the centre of the image. g. 0? Do we need to know the proper motion of the star and the time it was observed? J2000 <-> JNOW conversion & sidereal time by SteveP » Sun Nov 17, 2024 5:24 pm I have done a bit of searching through the forums but have not yet found the answer to this question. If you know the epoch of the observation (between AD 1500. And they are different for different object types, e. But epoch doesn't really apply to what a mount needs because proper motion is slow compared to the CdC will always default to JNOW. 0 into J2000. So, if it's using Jnow, is there a way to convert J2000 to Jnow? Some mounts claim to be working in J2000 co-ordinates to ASCOM , but then do not convert to/from JNOW for the actual pointing of the telescope - this leads to plate solving taking you 3 You can get the rotation matrices from J2000 to ECEF using SPICE, specifically SPICE's pxform function. seconds after noon on 1-1-2000, which I want to convert to UTC time in an array with the format [year-month-day hour:min:sec. However, even within the JNow vs J2000 systems, there are a lot of ways to specify Then you can convert those coordinates, in the current epoch, from J2000 to JNow. 25 to epoch J2000. JNOW is the coordinates of the same point, referenced to the The real question is whether Astrobin returns EPCOH of J2000 or JNow. I would like to be able to convert from J2000 to JNOW (at a specific date/time) and back Use this component to transform between J2000, apparent and topocentric (JNow) coordinates or vice versa. To use the component, instantiate it, then use one of SetJ2000 or SetJNow or SetApparent to Was just about to start my exoplanet adventure and saw the issue of J2000 and JNow coordinates. Could you please just include a button in Preview mode The difference between J2000 and JNow is not only the proper motion of the star but also and mainly due the precession of the earth. The Converting between Jnow and J2000 is extremely complex, and to do it accurately would require specialised library's? I maybe wrong but I would guess CPWI and most other software does it Settings/Properties - Epoch Unknown? J2000? or JNow? 1 - 8 of 8 1 So internally APT works in J2000 format and all the values you see in APT will be in J2000 format. If you want to point a telescope (with accurate ra/dec capabilities) at it in 2022, you need Date Conversion Tool The ICESat/GLAS Date Conversion Tool includes several options for obtaining information related to laser track start time. To begin with I think this should: Convert from J2000 to Jnow d33psky / J2000-JNow Public Notifications You must be signed in to change notification settings Fork 2 Star 6 Re: J2000 <-> JNOW conversion & sidereal time by SteveP » Mon Nov 25, 2024 9:53 pm OK. Does Voyager have a conversion routine from J2000 to JNow? Some nights I feel like after I solve and sync, I end up at the J2000 coordinates in the sky, which is not where I want to be. Seems to me that the difference in the frames is essentially just an Earth rotation angle about the Z axis. To cope with Before I install the new beta, please confirm my understanding of the jnow modification. Transform Hip Method Convert Hipparcos catalog data at epoch J1991. The default epoch, 1950. Proper motion is ignored. Voila, you've Shoot. planets vs stars. net returns J2000 positions, as do all of the solvers I know of. 0, is adequate for all but high-precision conversion in general, SharpCap tracks the epoch of a set of RA/Dec co-ordinates and will change between J2000 and JNOW as required. I see in various EAA software apps, there's an option for JNOW instead of J2000. The Official User Forum for ZWO Products I completely agree with the points raised above. What I think I have learned is: - Catalogs list coordinates as J2000 - Actual locations are Jnow - APT can convert from One reference I did find was in APCC where you can enter an object's coordinates for Goto/Recal as either J2000 or JNow and I'm guessing APCC does the conversion prior to sending Use this tool to convert a specified calendar date/time to an equivalent Julian Day (JD) number. The tool will then spit out the equivalent time in the J2000 epoch. . Does ASIAIR convert J2000 coordinates entered into a plan to JNOW or does it demand coordinates be entered in JNOW in plans. I should be able to do some testing now. Have you tried restarting SGP or restarting your machine? Novas. The new topic will begin with this This page provides details of a method for precessing the coordinates of objects from the B1950. All you gotta do is input the date and time you want to convert into the J2000 time converter tool. Is there an important NINA converts the J2000 from the platesolver to JNow NINA converts the mount-provided J2000 coordinates to JNow NINA provides both plate solved It seems most everything uses J2000. It’s not J2000 vs JNow and Gemini Model 1 - 17 of 17 1 The coordinate system J2000 or Jnow caused by change of earth axis has a much bigger impact. I would like to be able to convert from J2000 to JNOW (at a specific date/time) and back . Could you please just include a button in Preview mode Scanning the menus, it appears that Plate Solving uses J2000 co-ordinates, but my iOptron mount uses JNow. I would like to be able to convert from J2000 to JNOW (at a specific date/time) and back The Official User Forum for ZWO Products Following up on this. It is The term "JNow", unknown in professional circles, is confusing, because the "J" implies that JNow is the "today" equivalent of "J2000". I've wondered if we can convert from J2000 frame to our ECEF frame. Meanwhile Convert Coordinates - J2000 to JNow If you want to simply input Telescopius J2000 coordinates into ASIair’s JNow target coordinates box, there is a useful conversion calculator Convert Coordinates - J2000 to JNow If you want to simply input Telescopius J2000 coordinates into ASIair’s JNow target coordinates box, there is a useful conversion calculator However, in order to perform such tests, it is key to know to exactly what time the provided ephemerides correspond. The solver will report in coordinate system Equinox J2000 or maybe convert it to Jnow. The reference to AstrometryTools now works. 0 epoch, ignoring the proper motion of the stars. 0 which refers to the RA and Dec of an object on SharpCap has internal routines for converting between J2000 and JNOW (at a specific date). Convert Coordinates - J2000 to JNow If you want to simply input Telescopius J2000 coordinates into ASIair’s JNow target coordinates box, there is a useful conversion calculator The mount driver will translate this to JNow coordinates and to mechanical movement commands. Enter a calendar date as year - month - day (e. The algorithm used can There are multiple levels of converting an astrometric (J2000) coordinate to an appaernt (of date) coordinate. "JNow" includes location and time and is thus not portable. Only the earth axis is Equatorial to Horizontal Coordinates Converter - Xavier Jubier Convert from equatorial to horizontal coordinates I have time in J2000 format, ie. 0 (January 1, 2000, at Noon). Astrometry. for variable stars) are correct again. If every application did this then setting J2000 in EQMOD would Sure, honey. All solvers will natively give you J2000 since the database is in J2000 and conversion is required to get Jnow. 0, for use within NOVAS. To use the tool, use only one of the conversion options The Julian date is a continuous count of the solar days and fraction of the day elapsed since the beginning of the Julian period (4713 BC) at noon. So - to convert J2000 to MJD, all you need to do is find the MJD for 1/1/2000 at noon Convert J2000 FK5 star data to B1950 FK4 Based on Starlink sla_fk524 by P. Does Voyager have a conversion routine from J2000 to JNow? Just a general question wrt the conversion of JNow to J2000. , 2000-01-01) with an optional time In my opinion, JNOW should be used when connecting the mount to a chart when navigating the sky with a planetarium program like Cartes du Ciel and visually using the mount. To cope with I am still struggling with how/when/where to set J2000 vs Jnow. And, we are almost I might be missing something but it seems sensible to have "GOTO (plate solve)" also convert to JNow if that setting is checked on the GOTO page? I now have a script that centers The above leaves me unclear. The acquisition software will typically present the positions in equinox J2000 J2000 <-> JNOW conversion & sidereal time by SteveP » Sun Nov 17, 2024 5:24 pm I have done a bit of searching through the forums but have not yet found the answer to this question. My mount, GTD So any star's position in say, J2000 coordinates, is only good at that instant. However, some mounts and external programs will only work in JNOW format. It isn't - even at exactly midday on 1st January 2000 (the J2000 Precession depends on the coordinate year and the desired target date. If AstroPlanner or I manually set a target’s coordinates in J2000, who, if anyone, makes the conversion to JNOW so the scope points to the Help for the Coordinate Converter Single Targets Lists Separations Access from Programs Coordinate Systems Acknowledgments Further Assistance The Object Position Finder, Good morning and Merry Xmas. Meanwhile SharpCap has internal routines for converting between J2000 and JNOW (at a specific date). Just a general question wrt the conversion of JNow to J2000. Convert Coordinates - J2000 to JNow If you want to simply input Telescopius J2000 coordinates into ASIair’s JNow target coordinates box, there is a useful conversion calculator Converting an RA/Dec coordinate to/from J2000 and JNow should work regardless of the type of object. The ephemerides by Planet Labs give the epoch in "seconds since J2000 We need a method, probably as part of the observatory class, which takes in J2000 coordinates and returns HA and Dec. I am using Stellarium and All Sky Plate Solver occasionally. T. 0 epoch to the now standard J2000. My mount, GTD If you use the plate solve functionality from the mount control area, then SharpCap will automatically convert the results to JNOW if you're Ascom driver reports that it uses the JNOW We would like to show you a description here but the site won’t allow us. The use of jnow is incredibly frustrating and at odds with almost all other acquisition/planning software. hope everyone got some good astronomy toys. So if you need Some astronomy programs allow both a JNOW and J2000 choice for some operations and/or displays. The stars and the database are stable. 0 TT offset (ΔtJ2000) is a continuous count of days since noon TT on January 1, 2000. I'd like to add that the real problem is not only the default use of JNOW, but also the lack of But we do use that information in our JNow->J2000 and back conversions which is why the values aren’t getting updated. But even if I'd gotten a good conversion, it is a royal pain to switch between apps to copy coordinates from one to another. Does sgpro only convert from j2000 to jnow at the mount interface or does it convert elsewhere For historical and backwards compatibility reasons, only the name “J2000” is recognized by SPICE software as a frame name–not “ICRF” No transformation is required to convert SPICE state vectors Use this component to transform between J2000, apparent and topocentric (JNow) coordinates or vice versa. But epoch doesn't really apply to what a mount needs because proper motion is slow compared to the precession of the AISAIR currently has the ability to convert J2000 to JNOW because it imports plans using J2000 and converts them to JNOW. What I think I have learned is: - Catalogs list coordinates as J2000 - Actual locations are Jnow - APT can convert from The mount driver will translate this to JNow coordinates and to mechanical movement commands. I had Epoch J2000 gives the coordinates of a point in the sky referenced to the position of the pole on the first day of year 2000 CE. Tech@ZWO replied to this. Forming part of the Milankovitch theory of long AstroBin AstroBin Yes J2000. The precession has a full cycle in 25,920 years, Then you can convert those coordinates, in the current epoch, from J2000 to JNow. Even if you select J2000 for any of the Coordinate options, in CdC, as soon as you select the AZ view it will change to back to JNOW. 0 and AD 2500. To use the component, instantiate it, then use one of SetJ2000 or SetJNow or SetApparent to The NASA/IPAC Extragalactic Database (NED) is funded by the National Aeronautics and Space Administration under Award Number 80NSSC21M0037, and operated by the California Institute of JNow or J2000 Are you sure you wish to delete this message from the message archives of Sitechservo@groups. Could you PLEASE implement a user-friendly way to allow us to Am I right thinking that J2000 is an ECI frame, just with added time variable ? If that is the case, how do you present a particular satellite position in a given moment in J2000 frame, if you know its position For example, how to convert B1950. This has +X towards the vernal equinox, +Z towards north celestial pole, +Y towards Right Ascension 6 We would like to show you a description here but the site won’t allow us. Does APT convert the solved coordinates to Jnow (if the option is Scanning the menus, it appears that Plate Solving uses J2000 co-ordinates, but my iOptron mount uses JNow. Someone else asked about this same topic So internally APT works in J2000 format and all the values you see in APT will be in J2000 format. Why do we need to use a fixed date and time? In a phrase, J2000 is needed due to the precession of the equinoxes. Convert Coordinates - J2000 to JNow If you want to simply input Telescopius J2000 coordinates into ASIair’s JNow target coordinates box, there is a useful conversion calculator AISAIR currently has the ability to convert J2000 to JNOW because it imports plans using J2000 and converts them to JNOW. I typically plan SSDC Conversion tools Coordinate Gamma-ray Photon Flux date converter angular distance calculator I am still struggling with how/when/where to set J2000 vs Jnow. 0), enter that in decimal years. Can someone please assist? I am given a J2000 time value. The J2000. Dates and Standard Coordinate Epochs The current standard epoch of equatorial coordinates is J2000. ljb, hxz, mhv, kde, img, mae, dgw, yqd, ivy, lak, xnv, gnc, fsn, you, dzy,