diff --git a/guide/app_accuracy.tex b/guide/app_accuracy.tex index a87ccc49f3b40..1933a5815729f 100644 --- a/guide/app_accuracy.tex +++ b/guide/app_accuracy.tex @@ -61,7 +61,7 @@ \section{Stellar Astrometry} Even though you can follow movements of stars on the sky for tens of thousands of years, please note that the precision of these predictions are limited by the precision of the data we have at -the present time provided by Hipparcos for bright stars and Gaia. Most of the stars brighter than magnitude 10.5 +the present time provided by Hipparcos for bright stars and Gaia.\newFeature{25.1} Most of the stars brighter than magnitude 10.5 have 3D position and 3D velocity data (i.e., 6D astrometry) in our star catalogs, thus their 6D astrometry are computed at any epoch by assuming linear motion with constant velocity. These calculation provides arcseconds level accuracy of stellar position, arcseconds per year level accuracy of proper motions, arcseconds level accuracy of parallax and km/s @@ -69,7 +69,7 @@ \section{Stellar Astrometry} than magnitude 16.75, 2D computation is performed such that RA/DEC positions are computed from RA/DEC proper motions separately and assume constant proper motion. For stars fainter than magnitude 16.75, no astrometry propagation is performed hence their RA/DEC stay constant at any epoch. -In the study of \citep{deLorenzis:2018}, which emphasized sky position errors with bright high proper motions star like Arcturus, +The study of \citet{deLorenzis:2018} emphasized sky position errors with bright high proper motion stars like Arcturus, Dubhe, Sirius, Toliman and Vega which deviate noticeably from their correct locations even at around 2500BC with Stellarium 0.17.0 released on 21 Dec 2017. The star catalogs and astrometry propagation algorithms have been significantly improved in December 2024, which has solved the problem outlined in the study. But binary stars seem to break apart because Stellarium does diff --git a/guide/app_star_catalogue.tex b/guide/app_star_catalogue.tex index 7514b272b3c45..082c62ce3eec9 100644 --- a/guide/app_star_catalogue.tex +++ b/guide/app_star_catalogue.tex @@ -37,9 +37,9 @@ \section{Star Catalogue File Format}%\label{star-catalogue-file-format} \subsection{General Description}%\label{general-description} \label{sec:Catalogues:stars:general} -Stellarium's star catalogue data is kept in the \file{stars/hip\_gaia3} +Stellarium's star catalogue data is kept in the \file{stars/hip\_gaia3}\newFeature{25.1} sub-directory of the Installation Directory and/or User Directory (see -section~\ref{sec:Directories}). +section~\ref{sec:Directories}).\footnote{The data has significantly changed in version 25.1. The previous structure can be found in older guides.} The main catalogue data is split into several files: @@ -67,8 +67,9 @@ \subsection{General Description}%\label{general-description} \item[\file{name.fab}] \end{description} -When Stellarium starts, it reads the \file{starsConfig.json}\footnote{Or \file{defaultStarsConfig.json} file in Installation Directory} file, from which it determines the -names of the other files, which it then loads. The file \file{stars\_hip\_sp\_0v0\_6.cat} +When Stellarium starts, it reads the file \file{stars/hip\_gaia3/starsConfig.json}% +\footnote{Or \file{stars/hip\_gaia3/defaultStarsConfig.json} file in Installation Directory}, from which it determines the +names of the other files which it then loads. The file \file{stars\_hip\_sp\_0v0\_6.cat} contain spectral type of HIP stars. The file \file{object\_types\_v0\_1.cat} contain object type classification name for the main star catalogs. The file \file{gcvs\_hip\_part.dat} contains data about variables stars @@ -171,18 +172,6 @@ \subsubsection{Zone Records}%\label{zone-records} each zone. The total length of the Zones section depends on the number of zones. See table~\ref{tab:Catalogues:stars:record:zones}. -\begin{table}[htbp] -\begin{tabularx}{\textwidth}{llllX}\toprule -\emph{Name} & \emph{Offset} & \emph{Type} & \emph{Size} &\emph{Description}\\\midrule -num stars in zone 0 & 0 & int & 4 & number of records in this file which are in zone 0\\%\midrule -num stars in zone 1 & 4 & int & 4 & number of records is this file which are in zone 1\\ -\ldots & & & &\\ -num stars in zone $n-1$ & $4n-4$ & int & 4 & number of records is this file which are in zone $n$\\\bottomrule -num stars in zone $n$ & $4n$ & int & 4 & number of records is this file which are in the global zone\\\bottomrule -\end{tabularx} -\caption{Zones section} -\label{tab:Catalogues:stars:record:zones} -\end{table} \subsubsection{Star Data Records}%\label{star-data-records} \label{sec:Catalogues:stars:record:data} @@ -203,35 +192,49 @@ \subsubsection{Star Data Records}%\label{star-data-records} for record structure details. Details about vector algebra related to astrometric calculations can be -found in \citep{2012asas.book.....V}. For catalog with Star Data Record -Type 0, in practice to convert \texttt{x0}, \texttt{x1}, \texttt{x2} to +found in \citep{2012asas.book.....V}. For the catalog with Star Data Record +Type 0, in practice to convert $\mathtt{x0}, \mathtt{x1}, \mathtt{x2}$ to right accension $\alpha$ and declination $\delta$, one can use the following formulas: \begin{equation} \begin{aligned} -\alpha &= \arctan2(\texttt{x1}, \texttt{x0})\\ -\delta &= \arcsin(\texttt{x2}) +\alpha &= \arctan2(\mathtt{x1}, \mathtt{x0})\\ +\delta &= \arcsin(\mathtt{x2}) \end{aligned} \end{equation} -and to convert proper motion vector (\texttt{dx0}, \texttt{dx1}, \texttt{dx2}) to +and to convert proper motion vector $(\mathtt{dx0}, \mathtt{dx1}, \mathtt{dx2})$ to proper motion in right ascension $\mu_{\alpha^*}$ and declination $\mu_{\delta}$, one can use the following formulas: \begin{equation} \begin{aligned} - xy &= \sqrt{\texttt{x0}^2 + \texttt{x1}^2}; \\ - \vec{p} &= \left(-\frac{\texttt{x1}}{xy}, \frac{\texttt{x0}}{xy}, 0.\right); \\ - \vec{q} &= \left(-\frac{\texttt{x0} \cdot \texttt{x2}}{xy}, -\frac{\texttt{x1} \cdot \texttt{x2}}{xy}, xy\right);\\ - \mu_{\alpha^*} &= \vec{p} \cdot \left(\texttt{dx0}, \texttt{dx1}, \texttt{dx2}\right); \\ - \mu_{\delta} &= \vec{q} \cdot \left(\texttt{dx0}, \texttt{dx1}, \texttt{dx2}\right); + xy &= \sqrt{\mathtt{x0}^2 + \mathtt{x1}^2}; \\ + \vec{p} &= \left(-\frac{\mathtt{x1}}{xy}, \frac{\mathtt{x0}}{xy}, 0.\right); \\ + \vec{q} &= \left(-\frac{\mathtt{x0} \cdot \mathtt{x2}}{xy}, -\frac{\mathtt{x1} \cdot \mathtt{x2}}{xy}, xy\right);\\ + \mu_{\alpha^*} &= \vec{p} \cdot \left(\mathtt{dx0}, \mathtt{dx1}, \mathtt{dx2}\right); \\ + \mu_{\delta} &= \vec{q} \cdot \left(\mathtt{dx0}, \mathtt{dx1}, \mathtt{dx2}\right); \end{aligned} \end{equation} where $\mu_{\alpha^*}\equiv\mu_{\alpha}\cos{(\delta)}$. -\begin{table}[p] +\begin{table}[htbp] +\begin{tabularx}{\textwidth}{llllX}\toprule +\emph{Name} & \emph{Offset} & \emph{Type} & \emph{Size} &\emph{Description}\\\midrule +num stars in zone 0 & 0 & int & 4 & number of records in this file which are in zone 0\\%\midrule +num stars in zone 1 & 4 & int & 4 & number of records is this file which are in zone 1\\ +\ldots & & & &\\ +num stars in zone $n-1$ & $4n-4$ & int & 4 & number of records is this file which are in zone $n$\\\bottomrule +num stars in zone $n$ & $4n$ & int & 4 & number of records is this file which are in the global zone\\\bottomrule +\end{tabularx} +\caption{Zones section} +\label{tab:Catalogues:stars:record:zones} +\end{table} + + +\begin{table}[htbp] \begin{tabular}{llllp{75mm}}\toprule \emph{Name} & \emph{Offset} & \emph{Type} & \emph{Size} &\emph{Description}\\\midrule gaia\_id & 0 & long long & 8 & Gaia source id\\%\midrule @@ -273,6 +276,7 @@ \subsubsection{Star Data Records}%\label{star-data-records} \label{tab:StarDataRecord1} \end{table} + \begin{table}[htbp] \begin{tabularx}{\textwidth}{llllX}\toprule \emph{Name} & \emph{Offset} & \emph{Type} & \emph{Size} & \emph{Description}\\\midrule @@ -285,6 +289,8 @@ \subsubsection{Star Data Records}%\label{star-data-records} \caption{Star Data Record Type 2} \label{tab:StarDataRecord2} \end{table} + + \clearpage \section{Variable Stars} diff --git a/guide/guide.bib b/guide/guide.bib index 3aa28c2a8ea2c..3a3f61c593bf0 100644 --- a/guide/guide.bib +++ b/guide/guide.bib @@ -2183,11 +2183,12 @@ @article{Adler:2002 } @BOOK{2012asas.book.....V, - author = {{van Altena}, William F.}, + editor = {{van Altena}, William F.}, title = "{Astrometry for Astrophysics}", - year = 2012, + year = 2013, adsurl = {https://ui.adsabs.harvard.edu/abs/2012asas.book.....V}, - adsnote = {Provided by the SAO/NASA Astrophysics Data System} + adsnote = {Provided by the SAO/NASA Astrophysics Data System}, + publisher = {Cambridge University Press} } @ARTICLE{2016A&A...595A...1G,