AD ASTRA...

(last update: 18. Apr 2000, see at Hubble Space Telescope)

JPLJPL - Jet Propulsion Laboratory

Most of you will already know this fine resource, but especially for novices I will make two remarks:
 
  • it's the clear number One site for Solar System exploration with space probes with very much and brand new, actual material. It's even possible to check out the news section daily or at least two times the week and to find generally new messages about missions and results
  • also for other people:  if you search for video animations of objects of our own planetary system, follow this link: space videos . The reason is, that the animations of JPL are "only" about the missions or more precisely about the probes than the objects, but if you want really big video cuts, you should order    these per CD or PAL/NTSC from the JPL or another institution, because they    can easily exceed practicable sizes for downloading (with the only exception of really high bandwidth users with about 20 kBytes/s or more capabilities).


The level of this site is moderate, what means, that every interested person should be able to comprehend the presented facts, pictures etc. General the publication efforts of JPL set an positive example.


Extrasolar Planets Encyclopedia      US mirror site

I can simply not put a logo here, because this central homepage about planets outside our solar system presents none. First an important remark: don't email Jean Schneider, unless you really have important new information about the subject of this scientific site. Few things are worse, than getting much useless email if you are working hard at such a vast, complex and important homepage (and "beside this" working at your institute...).

For our French speaking friends there are especially good news, for this original French site offers - logically, I should say - also a French version; you find the link on top of the entry page.

It's probably necessary, to explain some of you usual astronomical abbreviations, to get the maximum use out of this homepage (if you have further questions, mail them (see above) to me and not to Jean Schneider, mail address see below).

One final principal remark: this site contains mainly text informations, but at some pages are also graphics and even animations presented.

Now the announced explanations: with the usual and up to now only working method for the detection of such planets it's only possible to get a minimum mass. This is the column M[.sin i ], where the inclination i (also incl., 2.last column) means the generally unknown and at best speculative angle between the line of sight and the perpendicular of the orbital plane (in which the planet moves around the star).

The semi major axis is the arithmetic mean of the minimum and maximum distance of the planet from the star, given in units of the earth-sun distance (= Astronomical Unit = AU) and the eccentricity is the deviation of it's orbit from a circle, it ranges from 0 (exact circle) up to near 1 (a very lengthy ellipse, like that of comets). Period means simply the time, that the planet needs to complete one orbit around his star.

Below the main star designation are listed: distance from earth in pc = parsec,   1 parsec are 3.2616 light years, the spectral type (better you read a book, if you are interested in this no way trivial classification, our sun has G2V as type in this system) and the apparent brightness for a certain (visual-like) wavelength of light (a logarithmic scale, our sun would have V=4.7 in a distance of 10 pc and lower values mean greater brightness!).

Finally there are updates of this page at the average one time a week, if it's interesting you much, check therefore one time at every weekend back there...


Hubble Space Telescope (HST)Hubble Space Telescope
Space Telescope Science Institute (STScI)Heritage Project

Hubble logoHubble logo Hubble summary site
 
 
This is the facility, which operates the Hubble Space Telescope. It's a public site with similar intentions as the JPL site mentioned above. The difference is of course the instrument: the only large visual (and near-infrared and near-ultraviolet) telescope, which orbits the earth and therefore being in the vantage point of airless space...

The other great difference is, that all types of objects except the sun are observed.

The second link above should be at most visited one time a month, there are the pictures considered to be the best by the team presented in various sizes, with explanations and more. This is truely designed primary for your viewing pleasure. Note: since April you can participate in the selection of the pictures, which are shown! Despite there is already a good response to this offer, you may vote for your own favorite, of course (in April they cite 8,000 votes for the May picture!).

The first is the main link and can be visited at most once a week. There are the complete archives of pictures, captions and also animations. The last deserve a warning: for these are scientists, they create simply large animations very often 5 MB or more in size, because they have the resources to cope with such things. But they warn you not about the size of them - be aware, that they can be very large and so cost a lot of time and money to download! Your only option is, to try the download of an interesting one and look at the display of your Browser to judge, if it's feasible...  The movies are sorted by insertion time, what means, that the newest is on top.

New third (!) official Hubble site: the third link points to a new page of the Space Telescope Science Institute, which is obviously intended as a summary homepage --- opposed to the news presenting first and the single spectacular image presenting second page. I recommend to watch its evolution.


 

(if you're missing a certain US magazine site, please read there, why I removed the link at least temporarily)
 

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comments, suggestions, corrections etc. to: stefan.urbat@apastron.lb.shuttle.de

(URL:  http://www.lb.shuttle.de/apastron/astro1.htm)