- Created new Body Class which downloads the occulting body information from online source. At the moment, it downloads only from the Small-Body DataBase. The Body class will be the manager for all the Body informations, such as Ephem, Shape, Ring, etc. [#51]
- New Class PhysicalData, which inherits from astropy.units.quantity.Quantity, is created to handle physical data with uncertainty, reference and notes. [#51]
- "pole_position_angle" and "apparent_magnitude" functions are now present in Body instead of Ephem.[#51]
- A new EphemHorizons was created which is strictly equal to EphemJPL (EphemJPL may be removed in v1.0). [#51]
- A shortcut was created in Occultation where the user can pass the coordinate of the star directly to Occultation, the Star object will be created automaticaly. [#46]
- prediction() now makes use of the user input of the star to calculate faster the occultation parameters. [#48]
- Star() is now able to fully receive astrometric parameters from the user. [#48]
- Star() is able to download and use the distance from Bailer-Jones et al (2018). [#27]
- "pole_position_angle" and "apparent_magnitude" is passed to Body Class. In Ephem, it will raise a FutureWarning. [#51]
- The Ephem classes are now passed through the Body Class which will have priority over Ephem attributes. Parameters such as "spkid", "radius", "H" and "G". [#51]
- All Ephem Classes now inherits from BaseEphem, which holds core functionality for all of them. [#51]
- The new Body Class was implemented in Occultation. For backward compatibility, the previous usage is still possible if the Ephem object have a name. The Body Class is only required if the object is a planet or a planetary satellite. [#51]
- prediction() now creates the time array inside each division to avoid memory overflow. [#48]
- prediction() now propagates the positions of the stars using only the proper motions before comparing the stars with the ephemeris. [#48]
- The new Body Class was implemented in prediction. For backward compatibility, the previous usage is still possible. [#51]
- Fixes issue that happenned in occ_params() when the instant of the occultation was outside the given range. The function now gives appropriate error messages. The automatic range search was increased to 50 min from central instant in a recursive search. [#45, #48]
- Star now calculates the robust propagation of the position of the star and correspondent uncertainties. [#18]
- Fixed bug in Star().__str__() where pmDEC was printed wrong. [#43]
- A small bug fix was made in Star with the units of the star position error when coordinates are local. [#51]
- Module to verify if kwargs are allowed was created. This was included throughout the code. [#8]
- Added a parameter that allows the used to plot a dot corresponding the center of the ellipse [#35]
- Property LightCurve.time_mean that returns the mean time of the chord (positive) or the mean time of the observation (negative). [#34]
- Function Observer.altaz() that calculates the altitude and azimuth for a given target and instant. [#34]
- Four new parameters were added to plot_occ_map(): path: for the user to select a directory where to save the plots; site_name: If True, the name of the sites will be plotted; chord_delta and chord_geo: for the user to plot the path of a chord from distance of the center or passing by some coordinate, respectively. [#35]
- Two methods were added to PredictionTable() to help the user to remove bad events from table: keep_from_selected_images() and remove_occ(). [#35]
- config module is now a directory. It now includes a module with decorators and another for variables. [#31,#35]
- In EphemKernel, code argument was replaced by spkid. When using 'code', a FutureWarning is raised stating code as deprecated and will be removed from v1.0. [#26]
- In LightCurve.immersion and LightCurve.emersion, an error will rise when these values were not instanciated or fitted. [#34]
- Now the user has the possibility to redefine tref, immersion, emersion, initial_time and end_time after instantiated. [#35]
- lambda_0 argument was replaced by central_bandpass and delta_lambda by delta_bandpass. When using 'lambda_0' or delta_lambda, a FutureWarning is raised stating lambda_0 or delta_lambda as deprecated and will be removed from v1.0. [#36]
- Occultation.new_astrometric_positions() now shows a warning when time is far by more than 1 day from the occultation closest approach. [#21]
- Occultation.to_log() and print(Occultation) added the polar radius, equivalent radius, the Sun-Geocenter-Target angle and the Moon-Geocenter-Target angle, geocentric albedo, the altitude and azimuth of the target for each Observer. [#17]
- In fit_ellipse(), pos_angle and dpos_angle were deprecated in favor of position_angle and dposition_angle. [#35]
- Changed "GCRS" to "Geocentric" in the string representation to avoid confusion about the reference frame. [#35]
- prediction() now calculates the ephemeris inside each division to avoid memory overflow. [#31]
- PredictionTable.to_ow() will now raise a warning if the radius or the error of the ephemeris is not present. [#35]
- Now Star downloads all parameters from Gaia and saves them in the meta_gaia attribute [#35]
- Added function get_position() to EphemPlanete. This corrects a bug that prevented Occultation to run with EphemPlanete. [#41]
- Fixed bug in EphemJPL where id_type was redefined inside __init__(). [#41]
- Fixed error that appears when the fit was done separately (immersion and emersion times). Now the final model agrees with the fitted values. [#9]
- Fixed error when the file with the light curve has three columns. [#19]
- Fixed error when the exptime within the LightCurve was set as zero or negative. [#23]
- Fixed error in the automatic mode of LightCurve.normalize(). [#34]
- Fixed bug that was raised in LightCurve.log() when there were no initial or end times for lightcurves instantiated with immersion and emersion. [#35]
- Corrected error calculation using err = sqrt(star_err^2 + fit_err^2) [#18]
- Occultation.plot_occ_map() now uses the fitted ellipse to calculate the projected shadow radius [#22]
- Corrected bug that raised an error when calling Occultation.get_map_sites() and there were no observation added to Occultation. [#31]
- Corrected bug that did not save the fitted params in all occultations when more than one occultation was used in fit_ellipse(). [#35]
- Added axis_labels and lw (linewidth) to Occultation.plot_chords(). [#35]
- Fixed error that was generated when only one prediction was found. [#16]
- Fixed error in the output format of PredictionTable.to_ow() when coordinate was positive [#35]
### Object Classes
The documentation of all classes and functions are on their docstrings, while the scientific part is presented in the full documentation. Here follows a list with the main Object Classes:
Ephem Three Object Classes created to generate geocentric ephemeris for a given solar system object. EphemJPL queries the JPL Horizons service and download ephemeris information. EphemKernel reads the BSP files to calculate the ephemeris using the Spiceypy package. EphemPlanet reads an ASCII file with previously determined positions and interpolate them for a given instant.
JPL Horizons - https://ssd.jpl.nasa.gov/horizons.cgi
Star Object Class created to deal with the star parameters. From the Gaia-DR2 Source ID or a sky region, it queries the VizieR service and downloads the star’s information. From Gaia DR2 Catalog (<font color=blue>Gaia Collaboration 2016a, 2016b and 2018</font>) it gets the RA, DEC, parallax, proper motions, G magnitude and star radius; from the NOMAD Catalog (<font color=blue>Zacharias et al. 2004</font>) it gets the B, V, R, J, H and K magnitudes. The user can calculate the ICRS coordinate of the star at any epoch. It can be barycentric (corrected from proper motion) or geocentric (corrected from proper motion and parallax). Also, the apparent diameter of the star is calculated using Gaia DR2 information, or some models such as <font color=blue>Van Belle (1999)</font> and <font color=blue>Kervella et al. (2004)</font>.
Gaia - Gaia Collaboration 2016a, 2016b and 2018 Mission: https://ui.adsabs.harvard.edu/abs/2016A%26A...595A...1G/abstract DR1: https://ui.adsabs.harvard.edu/abs/2016A%26A...595A...2G/abstract DR2: https://ui.adsabs.harvard.edu/abs/2018A%26A...616A...1G/abstract VizieR - https://vizier.u-strasbg.fr/viz-bin/VizieR NOMAD - Zacharias et al. 2004 https://ui.adsabs.harvard.edu/abs/2004AAS...205.4815Z/abstract Van Belle, 1999 - https://ui.adsabs.harvard.edu/abs/1999PASP..111.1515V/abstract Kervella, 2004 - https://ui.adsabs.harvard.edu/abs/2004A%26A...426..297K/abstract
Observer: Object Class created to deal with the observer location. The user can also download the ground-based observatories from the Minor Planet Center (MPC) database.
MPC sites - https://minorplanetcenter.net/iau/lists/ObsCodesF.html
Light Curve: Object Class that receives the observational light curve (with time and the occulted star normalized photometry relative to reference stars) and some observational parameters (filter and exposure time). It has functions to determine the instants that the solar system object enters in front of the star and leaves, (immersion and emersion times, respectively). The model considers a sharp-edge occultation model (geometric) convolved with Fresnel diffraction, stellar diameter (projected at the body distance) and finite integration time (<font color=blue>Widemann et al., 2009; Sicardy et al., 2011</font>).
Widemann et al. 2009 - https://ui.adsabs.harvard.edu/abs/2009Icar..199..458W/abstract Sicardy et al. 2011 - https://ui.adsabs.harvard.edu/abs/2011Natur.478..493S/abstract
Occultation: Main Object Class within SORA, created to analyze stellar occultations, and control all the other Object Classes within this package. Its functions allow converting the times for each observatory in the occulted body positions in the sky plane relative to the occulted star (
IERS Conventions: https://www.iers.org/IERS/EN/Publications/TechnicalNotes/tn36.html
Some extra Objects Classes:
PredictionTable: Using the prediction function within SORA results in an Object Class that is a slight modification of an AstropyTable. The added changes allow to create the occultation map for each prediction, convert into specific formats, such as OccultWatcher and PRAIA (<font color=blue>Assafin et al. (2011)</font>).
OccultWatcher - https://www.occultwatcher.net/ Assafin et al., 2011 - https://ui.adsabs.harvard.edu/abs/2011gfun.conf...85A/abstract
ChiSquare: This Object Class is the result of the fitting functions within SORA, such as _LightCurve.occ_lcfit()_ and _Occultation.fit_ellipse()_. This Class has functions that allow viewing the values that minimize the
#### INPUTS AND OUTPUTS v0.1
- ##### INPUTS
-
Event Related (Star and Ephem)
- Object Name or provisory designation
- Object Code (only for EphemKernel)
- BSP file and name (only for EphemKernel)
- DE file and name (only for EphemKernel)
- Ephemeris offset for RA and DEC -
$Delta alpha cdot cos delta$ ,$Delta delta$ (set as 0,0) - Occultation date and time
- Occulted star coordinates RA and DEC; or Gaia code
- Star offset for RA and DEC -
$Delta alpha cdot cos delta$ ,$Delta delta$ (set as 0,0)
-
Observer Related
- Site name and location (latitude, longitude, and height; or IAU/MPC code)
- Light curve file and name; or array with fluxes and times; or immersion and emersion times
- Exposure time in seconds
- Observational bandwidth in microns (set as 0.7
$pm$ 0.3 microns, Clear)
-
Fitting Related
- Initial guess for light curve fitting: immersion, emersion and opacity.
- Range to explore all three parameters
- Initial guess for ellipse parameters: center (f,g), equatorial radius, oblateness, and position angle
- Range to explore all five parameters
-
Event Related (Star and Ephem)
##### OUTPUTS
- Star
- Star Gaia-DR2 ID
- Star coordinates at 2015.5 and uncertainty - RA and DEC (hh mm ss.sss , +dd mm ss.sss, mas, mas)
- Star proper motion - in RA, DEC - and uncertainties (mas/yr)
- Star parallax and uncertainty (mas)
- Star coordinates propagated to event epoch and uncertainty - RA and DEC (hh mm ss.sss , +dd mm ss.sss, mas, mas)
- Star magnitudes G, B, V, R, J, H, K (mag)
- Star projected diameter and model (km and mas, model: GDR2, Van Belle, Kervella)
- Star offset applied in RA and DEC (mas, mas)
- Object and Ephemeris
- Object Name
- Object radius (km)
- Object mass (kg)
- Ephemeris kernel (version and DE)
- Offset applied in RA/DEC (mas, mas)
- Object’s distance (AU)
- Object apparent magnitude for the date (mag)
- Occultation
- Event date and time (yyyy-mm-dd hh:mm:ss.sss)
- Closest approach Angle - CA (arcsec)
- Reference time (yyyy-mm-dd hh:mm:ss.sss)
- Position Angle - PA (degree)
- Shadow’s velocity relative to the geocenter (km/s)
- Number of positive observations
- Number of negative observations
- Observer Information
- Detection status (positive, negative, overcast, tech. problem, other)
- Site Name
- Site MPC/IAU code (if any)
- Site coordinates - Latitude, Longitude and height (dd mm ss.s ; dd mm ss.s ; m)
- Light curve file name
- Number of images (lines in LC)
- Light curve fitting information (for each positive detection)
- Acquisition start time (yyyy-mm-dd hh:mm:ss.sss)
- Acquisition end time (yyyy-mm-dd hh:mm:ss.sss)
- Exposure time (s)
- Cycle time (s)
- Time offset applied in LC (s)
- Light curve calculated RMS
- Calculated normalised flux and bottom flux (standard = 1, 0)
- Band width and uncertainty (microns)
- Shadow's velocity relative to the station (km/s)
- Fresnel scale (s and km)
- Projected stellar size scale (s and km)
- Integration time scale (s and km)
- Dead time scale (s and km)
- Model resolution - size of synthetic LC point (s and km)
- Immersion Time and uncertainty (yyyy-mm-dd hh:mm:ss.sss +/- s.sss)
- Immersion Time and uncertainty - 1$sigma$ and 3$sigma$ (s)
- Emersion Time and uncertainty (yyyy-mm-dd hh:mm:ss.sss +/- s.sss)
$chi^2$ fit model- Emersion Time and uncertainty - 1$sigma$ and 3$sigma$ (s)
- Minimum Chi-square -
$chi^2_{min}$ - Number of fitted points for im- and emersion
- Number of fitted parameters
- Minimum Chi-square per degree of freedom -
$chi^2_{min-pdf}$ - Elipse fit procedure
- Fitted parameters: Equatorial radius and uncertainty (km); Center position (
$f_0$ ,$g_0$ ) and 1$sigma$ uncertainties (km, km); Oblateness and uncertainty; Position angle and uncertainty (degree)- Minimum Chi-square -
$chi^2_{min}$ - Minimum Chi-square per degree of freedom -
$chi^2_{min-pdf}$ - Number points used to fit ( X points from Y chords )
- Astrometric object center position at occ. time and uncertainty (hh mm ss.sss +dd mm ss.sss
$pm$ mas)- Plots and files (some are optional)
- Prediction map (Lucky Star model)
- Normalised light curve - for each site (x = time; y = flux)
- Chi-square map for immersion and emersion times (x = time; y =
$chi^2$ )- Light curve and synthetic LC- for each site (x = time; y = flux)
- Chords projected in sky plane (x =
$xi$ (km); y =$eta$ (km) )- Chi-square map for each ellipse parameter (x = time; y =
$chi^2_{param}$ )- Chords projected in sky plane and the best ellipse fitted with 1$sigma$ uncertainties (x =
$xi$ (km); y =$eta$ (km) )- Log file with all information