Martin Altmann


  1. OFFICE:
    Departamento de Astronomia
    de la Universidad de Chile
    der Universität Bonn Auf dem Hügel 71 (room 3.08) Casilla 36D
    Correo Central

    E-Mail : m a r t i n @ d a s . u c h i l e . c l
    Old E-Mail : m a l t m a n n @ a s t r o . u n i - b o n n . d e (still valid)
    Fax: (56) 2 / 229-4101
    Phone: (56) 2 / 97847-31 annex. 50

    Picture showing the Precordillera after a snow storm as seen
    from Cerro Calan, where I live and work (taken 21.04.2004)

  2. PRIVATE: Adresses have been removed (to prevent misuse), if you need to send me a letter, send it to my office address, if you need to know where I live, please mail me at one of the two mail addresses above. Thank you!
    Link to my hometown: Kevelaer (Germany) (in German)
    and the place I'm living now:Las Condes (Part of Santiago de Chile) (in Spanish)

Estudiantes de Practicum de Verano - DOWNLOADS

Aquis ustedes encontraran los documentos (en formato "odp" de open office y PDF de ADOBE - mejor para imprimacion) de los charlas yo teni en Enero 3, 2007.
Max's LINUX primer (en castellano) (PDF)
My Supermongo primer (en ingles) (PDF)


NOTE: As you might have noticed, I am no longer working at the Sternwarte of Bonn university. This does not mean that this page is no longer maintained. Actually a major upgrade of this page is planned in the near future. So please stay tuned!


My current research interests:

  1. sdB stars (and other horizontal branch stars) and the structure of our galaxy

    What are Horizontal Branch (HB) Stars?

    Horizontal Branch stars are evolved medium to low mass stellar objects in their core Helium burning phase. Stars, which have used up all their Hydrogen, and subsequently became Red Giants (RGB), which burn Hydrogen in their shell. Meanwhile the inert core grows in mass so that temperature and pressure of the core rise continuously. At one stage a point is reached when the core ignites and the stars starts its HB-phase. In the meantime the star has lost a large part of its outer shell due to strong stellar winds during the RGB phase. The resulting HB star now contains the 0.5 solar masses He-core and between 0.5 solar masses and very little (<0.01 solar masses) Hydrogen making up its envelope. Depending on this shell the star appears either red or blue with surface temperatures ranging from approximately 3500 K to 40000 K. At intermediate temperatures (6000-7500 K) the HB intersects the instability strip. That is where the RR Lyrae variable HB stars lie. The stars blueward of the instability strip are called blue HB stars (BHB) and subdivided into HBA (7500-10000 K) and HBB stars (10000-20000 K). The part which is even hotter than this is called the Extreme or Extended HB. The EHB stars are called sdB (cooler part, no or very little He in their spectra) or sdOB (hotter part, significant He in their spectra). The even hotter sdO stars are either evolved sdB stars or stars settling to become white dwarfs after their second Red Giant phase (AGB).

    HB stars and the structure of the Galaxy

    These stars are an useful tool for research trying to determine the structure of the older stellar component of our galaxy. In my PhD thesis I determine the physical, spatial and kinematical (i.e. effective temperature, surface gravity, distance, radial velocity and proper motion) of samples of sdB stars in two fields of high galactic latitude. Knowing the spatial distribution of a statistically complete sample of stars, one can determine the scale height of their distribution perpendicular to the galactic plane. This gives information about the population membership (halo or disk) of these stars. Examining the kinematics of stars shows us whether they have disk-like orbits (high orbital velocity, low eccentricities, small maximum z-heights) or have highly inclined, high eccentricity orbits featuring a low orbital velocity, which would characterise them as halo objects.

    Typical orbits of the different varieties of Horizontal Branch stars. Shown are the meridional plots of RR Lyraes (magenta), HBAs (red), HBBs (green) and sdB stars (blue). The difference in the kinematical behaviour of the HB stars can be clearly seen.

    Want to see how sdB stars move trough our Galaxy?
    Then download this MPEG-File (3.9 MB) showing the trajectories of 110 sdB stars (red) and the Sun (blue) as well as their current positions (green):
    sdB orbits - The Movie!
    Note: the stars move backwards in time over 1 Gyr
    More to come, so stay tuned!!!!!

    Collaborators: Klaas S. de Boer (Bonn), Heinz Edelmann (Bamberg), O.-M. Cordes (Bonn), Torsten Kaempf (Bonn), Philip Willemse (Bonn), Marcio Catelan (Univ. Catolica, Stgo.), Rene Mendez (Univ. de Chile, Stgo.)
  2. Establishing a catalogue of spectrophotometric standards in the frame of the DIVA satellite mission (In Collaboration with Uli Heber, Zorica Pavcovic (Bamberg) and Klaas S. de Boer (Bonn).
  3. Proper motions of Dwarf Spheroidal Galaxies (In collaboration with Rene Mendez (UdC), Edgaro Da Costa (UdC), Mario Pedreros (Universidad de Tarapaca, Arica, Chile).
  4. Wide Field MUSYC and CYDER Surveys. While these are like most surveys of this kind primarily designed to deal with extragalactic topics these two have a strong galactic section and even include the derivation of proper motions. I am looking for White Dwarfs (incl. cool White Dwarfs), substellar Brown Dwarfs and other stellar objects of interrest.

    A part of the CYDER C2 field (BVI)
    Full frame (JPEG 5 MB)
  5. General observing at Hoher-List Observatory
A research page with more information about the topics mentioned above is planned.

Download my dissertation (PhD. Thesis)
The DIVA Standard Star Archive Doesn't work yet :-(

Back to Sternwarte

Publication list

My list of publications


My current timetable for those who want to know where I am at the moment.

Programs and utilities

SuperMongo Macros

SM is a plotting programme written by Robert Lupton and Patricia Monger, which is widely used in astronomy and other sciences. In my long during use of this program, I inevitably wrote a lot of macros. One or two of them might be useful for other people too. Therefore I make them available to the public on this page.
(Disclaimer: Please note, that I'm not responsible for any damage or other problems caused by using these macros. You may freely use and change them, the risk is entirely yours!!!)

Martins Gallery

Astronomical images and photographs from our observatory Hoher List:

Picture of the month 11-12/2000: h & chi Persei (NGC 869 & NGC 884)
with HoLiCam (true colour) 17.2.1999, Observers: Oliver Cordes

Index page: Listing of all available images (quick reference)
Other gallery pages (astronomical and other) are planned.

Copyright notice: Since there are quite a few enquiries about publication of images from the Gallery Page, I have reviewed and updated the copyright notice, hoping to make things a little clearer.



La Silla: 3.6 m and NTT telescopes                                NGC 2997: picture taken with the 1.54 m Danish Telescope
                                                                                       and DFOSC

NGC 5128: The brightest elliptical galaxy in the sky has
obviously interacted with a dusty object, such as a galactic disk.
Image taken in BVR passbands with the 1.54 m Danish Tele-
scope and DFOSC on 03.05.2002 (The absorption due to
cloud cover was at the time approximately 6 mag).

It never snows in a desert, like the Atacama desert, least of all, when it's almost summer! Well, see for yourself (Link refers to a series of pictures taken on the 31.10.1999)

A page with informations (and links) about the various observatories I have visited and the telescopes I have observed with is planned.

Meanwhile for people who cannot wait to see how the weather is like at typical observatories:



Links to official sites and other sites concerning some of the observatories, I've been to:


Pages concerning my private interests, hobbies and other things will be made available soon!
The first site concerns two of my greatest hobbies,
travelling and photography:

Gallery page showing photographs from all over the world:
This is still a very preliminary version, which will continue to grow over the next months. So check in every now and then, as new images will be put on the site, as well as new destinations, and new page design etc.

Pictures taken durning my 3 month stay at ESO in Chile (January - March 2003)


A page containing my favourite links (astronomical and other) will be implemented shortly.
And last but not least, a page about the company I've learned to hate most of all (in German) ....
Das beste Argument fürs Autofahren: Die BAHN!!!!

Back to:

First version: 09th September, 1996
Last update: 03rd January 2007

Please send remarks about my homepage to Martin via E-Mail to m a r t i n @ d a s . u c h i l e . c l
[an error occurred while processing this directive]