AD ASTRA...  page 3

(last update: 9. Jan 1999)

false color galaxyWindows to the Universe
Another great site with many options (for example, also for shockwave flush users) and many pictures and some animations of astronomy and space flight (manned and unmanned). Explanations of planetary compositions and inner layers for example are also included. Partially the loading is not very fast, due to large collections of pictures on the page actually being loaded. The pictures are often in high resolution and therefore relatively large.



This site presents diverse online calculation programs and in the light of such catastrophe exploiting movies like "Deep Impact" or "Armaggedon" I guess, that many could be interested especially in the above linked page, where you can live out your mass destruction fantasies. Dependent of size, composition (primarily a question of density) and impact velocity (depends primarily of inclination and eccentricity of the impactors orbit) it can be calculated, how severe the consequences of an impact would be. And this you can execute not only for our, but also for all other major planets of our solar system; of course the differences in atmospheres and escape velocities (these set the lower limits for the impact speed) and surface types are included, when the result is presented. The results are of a rough nature, the displayed precision is arteficial (no general rounding is  applied on the results). For example the angle of the incoming impactor against the surface perpendicular is not included - but this has indeed only a slight effect for the outcome, unless the angle is near 90 degrees.


German FlagSterne und WeltraumSterne und Weltraum

Diese Homepage der einzigen populärwissenschaftlichen deutschen Astronomiezeitschrift ist wie diese einmal im Monat sinnvoll aufzusuchen. Sie enthält neben einer Inhaltsangabe mit Bildern auch kurze Unterschriften und soll hauptsächlich auf das aktuelle Heft Appetit machen. Wer Interesse hat, kann direkt "oberhalb" dieser Seite auch eine der führenden astronomischen Einrichtungen in Deutschland besuchen, da die Domain vom MPI (Max-Planck-Institut) in Heidelberg zur Verfügung gestellt wird. Letzteres betreibt u.a. auch das Observatorium auf dem Calar Alto in Spanien, dessen größtes Fernrohr 3,5 m Öffnung hat. Anmerkung: die Seite arbeitet mit Frames und JavaScript.


Vizier signHipparcos Star Catalog by Vizier

This is a great online resource for astronomers (also for serious amateurs). It contains along with others the famous and not long ago published HIPPARCOS astronomy satellite catalog, which presents the positions and - less accurate - the apparent brightnesses of around 100,000 stars with greatest and over 1,000,000 stars with somewhat less, but also unprecedented accuracy (with a few examples). With a good front end you can use diverse star designations, than the so-called SIMBAD system resolves this and identifies the star(s), of which you want to know these values. Of course you can also specify the coordinates respective ranges of coordinates, to get the most accurate star positions in existence so far.


The Nearest Stars according HIPPARCOS

This is an overview of the HIPPARCOS-revised list of the next stars to the sun in the for non-astronomers somewhat more convenient unit of light years. A few distances had to be took from another source (Yale Catalog), because the sensitivity of that satellite was limited in respect of the apparent brightness of the stars - and as you can see even in the revised list, what has partly remarkable changed, most of the stars near the sun are such feeble ones, that some were below HIPPARCOS capabilities (at least you can confirm it, if you know most of the listed stars).


Astrophysics abstracts, US site
Astrophysics abstracts, German site (also in English)

These are really research instruments and therefore useful for experts of astronomy and physics only. But it seems to be a valuable resource for viewing abstracts of articles in print and also enables access of the pre-print version of the articles. Indeed, more an institute and university tool. Non-experts should ignore it, before they get confused...


hypothetical surface picture of outermost pulsar planetPulsar Planets page

This little homepage was created to show some of the most exotic objects yet known: when they were discovered, no astronomer, who is honest, would have been expected, that there could be planets orbiting neutron stars (more precisely: pulsars). The reason is, that neutron stars, often acting as pulsars, are remnants of giant stellar explosions far beyond out human imagination. These supernovae events are so violent, that every companion of such an exploding star is literally blown to dust and gas. Therefore only one reasonable explanation remains for the existence of such objects: they must have built themselves after the explosion - accreting processes can obviously work even under such circumstances, to build objects of such masses.

Even more, the both well determined planets of PSR1257+12 (an radio astronomic designation for this pulsar) have masses around three times of the mass of our earth and are so far the only known objects in a similar mass range (remember: the up to now known planets of "normal" stars have masses of at least 150 times the mass of our planet).

The page offers a few little pictures to support the imagination and a few MPEGs of roughly 1 MB size, showing the orbits of the discerned pulsar planets (eventually you have to use the index listing of the not protected directories, to access all pictures and MPEGs, if you want).


The International Astronomical UnionInternational Astronomical Union

This official homepage of the IAU is mainly an instrument for communication and to present an overview of the commissions and these combining divisions of the IAU. There is at least now not much material presented, but I think, the interested and serious amateur astronomers should know about this site.


SETI Institute logoSETI Institute

This is not a pure astronomical subject. But because it's the search project, mainly sustained by (radio) astronomers, I list it here and not as biological topic.

The Search for Extra Terresstrial Intelligence was founded by Frank Drake decades ago, and there were many attempts to receive signals from the probably, but so far nonetheless hypothetical other existing technical civilizations.

At this site you can get all the stuff related to this subject. Because the government cut the funding a few years ago, only private money carries it now (for example, computer producers and a few other give money to it). Of course you can made your own donation to them. But beside the money needed they feature also a certain lack of computation power. That's the reason for the offer, to join in computational efforts to analyze the received radio signals and eventually one day extract the searched type of signals.

This offer you can read there:  SERENDIP at Berkeley . Of course this is first an 
experiment, but in other research cases (so the hunt for Mersenne numbers) it was already proved, that such enterprises are feasible even on a world wide base. And all you need for this is, to install the there offered screensaver...


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