- The Voyager 1 and Voyager 2 space probes launched in 1977 are still calling home. Carrying only cassette tapes and 256KB of memory the two probes have entered the interstellar space – the region beyond our solar system – their weak signal send temperature and other information back to earth.
- Gravitational waves are ripples in the structure of space that move at the speed of light. They cause the distance between objects to increase and decrease. Coalescing binary neutron stars may be one (barely) measurable source of gravitational waves.
- Neutron stars, what remains of some stars after they collapse, can rotate up to 600~700 times per second.
- The Sloan Great Wall is a giant wall of clustered galaxies measuring 1.3 billion light-years.
- A gamma ray burst or supernova can release as much energy as our sun will in its 10 billion year life.
KStars is a an open source freeware planetarium program from KDE, the linux platform group. KStars is available for Windows, requires the Microsoft Visual C++ 2015 Redistributable to run on PCs and it will automatically download it if it is not installed.
The program features 100 million stars, 13,000 deep-sky objects and thousands of comets, asteroids, satellites and other sky object in its catalogue. Objects can be added manually or via other downloaded add-ons (see the Data menu).
As with other similar programs choosing a location is the first task after running the program. The program can import and use .fits images for detailed imagery. Moving the mouse object names are displayed as tool tips and right clicking on any provides a wealth of information about the object including viewing images and the option of adding it to a wishlist for observing.
The program window can of course toggle on and off display of horizon, stars, deeps sky objects, planets, milky way, equatorial grid, constellation lines, names and art and also supernovae and satellite positions.
Besides viewing the sky from any location one can also chose a time to view the sky, choose any set time or move in steps to the past or the future. The passage of time can also be sped up to view the changing sky faster. The Pointing menu can change the view based on which direction the viewer is looking at and also center on an object and keep tracking it.
The Tools that come with KStars are really useful for both the amateur sky watcher – with an ‘auto suggest’ tool in the works – and the professional. The calculator provides a lot of information such as object positions, coordinates and radial velocities, Julian dates and sun and moon rise and set times. The Observation planner displays information based on a chosen object, a list can be created and saved for any upcoming sky viewing. The planner includes a ‘What’s up tonight’ tool and the objects added to the wish list can be viewed here. The Sky calendar displays or plots planets’ tracks in the sky.
The program also supports interfacing – using INDI and KDE’s own Ekos platforms – with telescopes to drive the viewer to an object and capture images.
A KStar handbook is accessible from the help menu that provides a wealth of info on every feature available.
Hallo Northern Sky is an educational, fun and fascinating planetarium program for windows and linux machines. It features around 30,000 objects and many more stars in its catalogue and can find any of them, provide descriptions and high resolution pictures with planets ones showing surface features. It can retrieve updated information online for more objects such as asteroids and comets too.
The first action after installing the program is to save a location, the program prompts the user to do so on first start or if there is no location saved. The only input type requires the user to know his/her location’s longitude and latitude (as opposed to a program like Stellarium that can set a user location by name). The program settings is where one can download or update the aforementioned additional or newer lists and images. Within the same settings (File —>Settings) the program interface can be tweaked to use bigger fonts, different fonts (instead of the default Comic Sans) and different colors. The Settings tab of the Settings (!) has options to change local file settings, use different equinox epochs and make corrections for atmospheric effects.
The program has multiple editors to load or edit astronomical data including images (.fits) files and asteroid and comet databases manually. The Search menu loads object (planets, moons, deep space objects, stars, constellations) names and can center on an object’s location. Supplementary or extra databases can be downloaded from the developer site and searched as well. These include additional galaxies and stars. The Objects menu is like loading specific supplements or databases and acts as a filter to view certain objects, for example to filter magnitude or use other deep sky maps that show farther objects. The Date menu can show the sky as it looks 1 hour from now, 1 day from now, tonight or any date.
Moving the mouse on the program window and left clicking on an object provides information about it on the upper left side of the window. Name, brightness, right ascension, declination, magnitude and more is given. Right clicking offers more like centering on the object, downloading images of an object and if no object is selected using one of online resources to search that chosen area of the sky. The Animation option (Screen —>Animation) lets the user visualize movements in time increments and follow planets or star movements.
Use the mouse wheel to zoom in and out or Ctrl+R for the aforementioned animation. The program has many hot keys built in. The extensive help file on the same page has lots more info.
Information can be copied to the clipboard when it is displayed on the status bar, just left click on the status bar to copy information about the clicked on area. ASCOM is supported, Hallo Northern Sky can interface with compatible telescopes and direct them to point to objects.
Aciqra (Version: 2.2 tested) is an open source planetarium software. It is one of the more complete ones available. It features star catalogs and NGC and IC catalogs that include millions of stars and 1000s of deep sky objects such as galaxies. It offers corrections for atmospheric refraction and other enhancements to be as accurate as possible in tracking stars and other objects. It also provides extra information on objects such as asteroid and comets and events such as eclipses.
The interface of the program is not the best but it does try to stay true to the claim that it is made to be efficient. The color and contrast of the buttons is the first issue when using Aciqra. They almost mix into the sky image behind them.
The bottom of the program from left to right features the buttons to exit, correct for refraction, track for earth’s rotation, toggle night vision mode (red color) and toggle current view information (universal time, location, field of view, right ascension, declination, azimuth and altitude).
The right hand side features the time control (view the sky in the past and future), label data which lets the user view very useful information on the objects in the sky like magnitude brightness, color (star temperature indicator), common name, scientific name and size. Object labels highlights constellations, stars, solar system and deep space objects. Further up the right hand side are toggles for the visibility of stars, deep sky objects, solar system objects and ground level.
The program opens with a DOS window where it takes longer than one would expect to load the objects and other information. Also upon first install it opens with its configuration settings text file where default user location, font and many other settings can be viewed and edited. It has some of the mouse and keyboard controls to navigate and move within the sky but the scroll wheel does not zoom in and out as I expected. Aciqra includes an option to save the current sky view as an image. It is available for Linux as well.
Stellarium is described as
Stellarium is a free open source planetarium for your computer
Stellarium is an excellent companion for the hobbyist and the curious astronomer. It has an attractive interface that is at the same time educational. Stellarium provides a view of the sky similar to the one that would visible to the naked eye at any given time.
The program has two slide-in menus at the bottom and left hand corners of its interface and they offer tabbed menus that control a multitude of settings and features. The list of features is extensive and Stellarium is really a program that requires its multi-page *.pdf userguide. Setting a location is probably the first option to use as this will show the sky as it looks where you are. Location is set via the left hand slide-in menu and it is also possible to view the sky as it is in other locations and then of course to set one’s own as default. Mouse dragging is used to move around the sky. Mouse wheel zooms in and out. Time control, in the bottom slide-in menu, shows the position and movement of stars and planets in the past and future, in varying speeds.
The Sky and viewing options window has many choices for the landscape or ground that will be the program’s setting. It is possible to set if planets are shown, how much the stars twinkle, if an atmosphere is shown and even how much light pollution there is. There are numerous paragraphs and text on the history of astronomy in the Starlore tab.
The Search window (also invoked by pressing the F3 button) searches the extensive list of stars and planets in its database that includes the likes of the Hipparcos Catalogue.
The Configuration window is the place to play around with the system time, download more star catalogues and to try out scripts. Script support is limited as of this post (version 0.10.2) but more is promised.
The bottom slide-in menu offers the tools that would be most used when running Stellarium. Beside the aforementioned ability to move time faster to track star and planet movements here one can switch to full screen mode and night (red colored screen to preserve night vision) mode. Centering the highlighted or chosen star on screen and switching between equatorial and azimuthal mounts are two other useful options. Toggling planet labels, nebula positions, atmosphere, ground, constellation lines, art and labels on and off further enriches the experience and all are done via the said menu.
The aforementioned *.pdf userguide shows the breadth of options and possibilities of Stellarium. From everything like scripting, creating landscapes, adding Nebula images, taking screenshots (using Ctrl and s keys) and to the many command line parameters.
Stellarium is open source cross platform software and requires a graphics card capable of rendering OpenGL. An *.ini configuration file written into the program folder is accessible from the program’s start menu and offers another way to tweak the characteristics of Stellarium, for example the presentation font can be changed here but there is much more and some are detailed on the FAQ page.