The observatory in Bogenhausen
From positional astronomy to modern astrophysics
An interim observatory, set up for topographical survey purposes
in 1805 on the premises of today’s Munich Ostbahnhof, became an
official institute of the Bavarian Academy of Sciences in 1807.
Regular observing was never undertaken there, though.
In 1816/17, a prestigious new building was erected to the east of
Bogenhausen, a village at that time.
In 1827, this observatory was put under the offices of the
newly-founded General Conservatory of scientific collections of the
State of Bavaria.
The office of curator of the observatory and the chair in astronomy
of the Ludwig-Maximilians-Universität München has been held
by the same person since 1852.
On March 18, 1938 (retroactively as of April 1st, 1937), the
observatory was affiliated to the department of physics of the
Ludwig-Maximilians-Universität München and thus became the
Although the charter of the Bavarian Academy of Sciences (1759)
does not explicitly call for the construction of an astronomical
observatory, two observatories were subsequently built on the outskirts
of Munich, by private initiative.
Owing to a lack of qualified personnel, these 2 observatories only
existed for a short period of time and no real observing was done.
The first was set up by Johann Georg Dominicus von Linprun (1714–1787)
in a tower-like building on a bastion (today:
Prinzregentenstraße, vis-à-vis the Haus der Kunst)
(1760–1769/70), the second by Peter von Osterwald (1718–1778)
in a mansion on the Gasteig (today:
Munich cultural center) (1773–1778).
The situation changed when – as a consequence of the political
and military situation at the beginning of the 19th century –
surveying was systematized in Bavaria under the control of French
Successful surveying could only be carried out on the basis of
astronomical position determination.
Therefore, the former Benedictine and astronomer Ulrich Schiegg
(1752–1810) was appointed Astronomer Royal in Munich.
In January 1803 he installed a small observatory in the northwestern
tower of the former Jesuit college in the Neuhauser Straße – since
1783 the location of the Bavarian Academy of Sciences.
Cooperation with the French surveyors was not without problems,
however, and when Schiegg called attention to inconsistencies in the
surveys, he was removed from office upon instigation of the French
The astronomer Karl Felix von Seyffer (1762–1822), who enjoyed good
relations with the French army command, was appointed his successor.
He was charged with the construction of a larger observatory by
Elector Max IV Joseph (1756–1825, reigned 1799 and 1806–1825).
Seyffer immediately had Schiegg’s instruments transported to a wooden
hut in the designated location near present-day Ostbahnhof between the
villages of Haidhausen and Ramersdorf, but made no further progress.
Only in 1807, when the interim observatory became a part of the
restructured Bavarian Academy of Sciences, did things slowly improve:
several astronomical instruments were ordered from the emerging
precision mechanics firm of Utzschneider, Reichenbach, and Liebherr
in Munich, because the available instruments were out of date.
The establishment of Bavaria as a kingdom (1806) and the demand for
better public presentation enhanced the process at first.
When the instruments were delivered (1811/12), the interim observatory
turned out to be too small for them to be installed optimally.
The idea of an extension or a new building, perhaps at a different
location, became increasingly attractive.
The project was delayed due to financial problems and due to Seyffer’s
“astronomical inactivity”, as criticized by his contemporaries.
In fact, surveying was of more interest to Seyffer, and in 1813 he
was given notice and was finally relieved of his office as Astronomer
Royal in 1815.
The Royal Observatory of Bogenhausen according to a lithograph by
C. Lebschée from 1830.
The projecting center part, the meridian hall, contained three transit
instruments, one of which was the meridian circle by Reichenbach.
The dome to the east (on the right side in the picture) contained
an equatorially mounted astrometry telescope, the one to the west
(on the left side) served to set up portable instruments.
Shortly thereafter, on April 1st, 1816 the astronomer Johann Georg
von Soldner (1776–1833) was appointed Seyffer’s successor.
Soldner had been a member of the survey commission since 1808 where
he had set up the theoretical basis of the Bavarian survey.
Whereas things had progressed rather slowly in the past, events now
on April 18, 1816 the Academy presented construction plans that
probably stemmed from Seyffer.
Then on June 4th, 1816 King Max I Joseph gave the order to build the
new observatory, and on August 11, 1816 the ground was broken on a
hill to the east of the village of Bogenhausen.
It had been decided to build the new observatory at a new site.
The place was not badly chosen, since the observing conditions were
excellent and Munich was within easy reach.
Furthermore, a decree was issued forbidding any construction or
plantation in the vicinity that was likely to disturb the work of the
future observatory, and which was indeed effective for several decades.
Under the supervision of the Royal building inspector Franz Thurn
(1763–1844) the construction progressed speedily and on November 15,
1817 the basic structure was completed.
It then took another two years to complete the interior and install
The horse-shoe shaped floor plan of the building included the meridian
hall at its center and two observing towers on either side.
The building housed the best instruments available at the time.
The primary instrument was a meridian circle from the
mathematical-mechanical institute of Reichenbach and Ertel.
Routine observing with this instrument commenced in December 1819.
The world’s best-equipped observatory, the Royal Observatory of
Bogenhausen, had gone into operation.
The meridian circle by Reichenbach and Ertel according to a photograph
from around 1900.
It was one of the best meridian circles of the world, the graduation
of its scales having been made with Reichenbach’s famous dividing
engine, improving the accuracy of stellar declination measurements
by a factor of 10.
The classical era
Soldner saw his main task at the new observatory in consolidating
the basic principles of astronomy by numerous measurements of the
positions of the sun, the moon, the planets, and the fundamental stars.
But this was soon interrupted for a short time in March and April
of 1820, when Joseph von Fraunhofer (1787–1826) continued his
spectroscopic studies of planets and bright stars, started earlier
at the optical institute at Benediktbeuern.
His new apparatus for experiments on the nature of the light of
fixed stars was installed in the western tower of the observatory.
Fraunhofer had found dark lines in their spectra similar to those
he had detected in the spectrum of the sun which he then measured
accurately and published in 1817.
Assisted by Soldner, Fraunhofer measured the position of the lines
in the spectrum of Sirius using a micrometer and investigated the
possibility that the refraction of stars of different colors behaved
Thus, the Observatory in Bogenhausen became the first observatory
in the world in which spectroscopic observations of the planets and
stars were performed.
The Scotsman Johann von Lamont (1805–1879), who succeeded Soldner
as director of the observatory in 1835, continued the spectroscopic
surveys using the giant telescope which was delivered in
the same year and installed in a newly constructed building on the
In the summer of 1836 he placed a small prism behind the eye-piece
of the telescope, which enabled him to measure the spectra of stars
40 times fainter than had been possible with Fraunhofer’s apparatus.
Lamont analyzed the spectra of more than two dozen stars, kept records
of their appearance, measured the positions of the strong lines and
left the first pictures of spectra of stars in his observer’s log.
Unfortunately, neither he nor Soldner recognized the potential of
stellar spectroscopy or the immense amount of physical information
contained in the lines.
It was only starting in 1860 that spectroscopic methods became a
ground-breaking research tool in astronomy, physics, and chemistry,
remaining so until today.
Although the refractor continued to be the world’s best telescope
in the following years, Lamont discontinued his observations with it
after some time and from 1840 on limited his astronomical activities
to position measurements of faint stars, using the meridian circle
His main interest turned toward investigating the Earth’s magnetism,
and the observatory gained a world-wide reputation through Lamont’s
fundamental contributions to this field.
Lamont built a geomagnetic observatory on the grounds of the
Bogenhausen observatory and travelled widely in Bavaria, northern
Germany, France, Spain, and Denmark to perform measurements.
His aim was to find magnetic regularities and to construct magnetic
maps of these countries by measuring the direction and intensity of
the Earth’s magnetic field.
He developed a portable magnetic theodolite of which about 45 were
built in the observatory’s workshop and sold to interested scientists.
These sophisticated instruments were used in expeditions to southern
Africa, Australia, and central Asia, or used in observatories.
With a lens diameter of 28.5 cm and its high quality optics, the
Fraunhofer refractor was the best telescope of the world for the
4 years following its installation in 1835.
The telescope had been commissioned in 1825.
Before his death in 1826, Fraunhofer had designed the telescope
mount and melted the glass block from which his successor Georg Merz
(1793–1870) later ground the lens.
Lamont’s successor, Hugo von Seeliger (1849–1924), who was the
observatory’s director from 1882 until his death, returned the
observatory’s main activities to astronomy, without losing sight of
the geophysical studies.
Shortly before the turn of the century, the Bavarian Academy of
Sciences, eager to continue the tradition of geophysical observations
in Bogenhausen, constructed a new geomagnetic observatory.
A seismological station soon followed.
In 1922, these facilities were officially designated the geophysical
Seeliger’s theoretical work on celestial mechanics, error analysis, and
stellar statistics made him the foremost German astronomer of the time.
Although practically all his ideas (for example his
mathematical-analytical model of the structure and size of the galactic
stellar system and his nova theory) became astronomical history soon
after his death, no longer standing up to the scrutiny of modern
findings, it is to his credit that he recognized basic problems and
attempted to solve them.
In this, Seeliger influenced the astronomical world-view of his time
and enhanced the Bogenhausen observatory’s reputation in the field
Foreign scientists came to visit time and again, and Seeliger’s
personality and aptitude as an excellent and stimulating teacher
attracted many students over the years.
One of the most brilliant of these was Karl Schwarzschild (1873–1916),
who obtained his doctorate under Seeliger in 1898 and to whom modern
astrophysics owes many ideas that are still valid today.
But Seeliger also viewed the new developments in physics (such as
quantum mechanics and the theory of relativity) with considerable
skepticism, and was reluctant to adopt innovations.
Thus he was ultimately responsible for the Bogenhausen observatory
sinking into relative insignificance in the coming decades.
The observatory site around 1900:
The main building erected in 1816/17 can be seen on the left; on the
right, joined to the main building by a connecting passage, is the
refractor building set up in 1835, housing the Fraunhofer refractor.
From the turn of the century onwards, the expanding city of Munich
increasingly encroached upon the observatory.
But plans for the Possartstraße took account of the astronomers’ needs:
the road was built in extension of the meridian circle in a strictly
north–south direction, so that meridian circle measurements could
go on unhindered.
Much of the observatory was destroyed in the heavy air raids of
July 1944, and reconstruction took until 1954.
1949 additionally brought a radical change:
all geophysical equipment was removed from the observatory site and
annexed to the institute for applied geophysics that had been newly
created at the Ludwig-Maximilians-Universität in 1948.
At the same time, the solar observatory on Mount Wendelstein, which had
been built for military purposes in the Alps in 1941, was affiliated
to the observatory.
The modern times
The turnaround came when Peter Wellmann (1913–1999) took office as
the observatory’s director (1961–1982).
Astronomical observations seeking to find answers to current problems
in astronomy were no longer possible in densely populated cities.
It had become clear that only through radical change could the
observatory hope to catch up with the progress in astrophysical
research that had been made in the meantime, particularly in the
As plans were already being made in Europe for providing shared
access to modern observational instrumentation at sites chosen for
their favorable meteorological conditions, Wellmann could for the
time being focus on creating a modern working and teaching environment.
In 1964, the nearly-150-year-old observatory building was demolished
and the construction of a new building on the historical site was
In October 1966, after more than 2 years of construction, researchers
could finally take up their work in the new building, consisting of
an auditorium, several seminar rooms, modern offices, and above all
a sophisticated computer system.
For historical reasons, the institute kept the name of
“University Observatory” (Universitäts-Sternwarte München, USM).
The main building of the old observatory was demolished in 1964 and
a new modern institute building was constructed on the same site in
the following 2 years.
The move-in took place on October 10, 1966.
The name “University Observatory” was preserved for historical
Scientific interest at the institute now focused on astrophysics,
especially in the theory and calculation of the structure of
stellar atmospheres, using the latest results in radiative transfer,
hydrodynamics, and atomic physics.
Stellar spectroscopy had thus returned to the Bogenhausen site,
its place of origin.
Besides this, significant attention was given to the analysis of the
physical properties of particular types of variable stars.
The institute also achieved success in the development and construction
of a series of new observational instruments, many of which were
deployed at the European Southern Observatory (ESO) at La Silla in
Chile, which had taken up operations in 1969.
ESO soon became the leading optical observatory in the world.
Astronomical research in Bogenhausen had undergone a basic change:
the gathering of data and the reduction and interpretation of
measurements were no longer done in the same place.
Observations were and are being made at remote observatories, or with
Observing runs must be planned in detail in advance, subject to the
approval of an international research committee that judges the
applications and allocates the scarce observing resources at the
At the home institute, the results are analyzed, interpreted, and
published in international journals.
The European Southern Observatory (ESO) on the 2400-m-high Cerro La
Silla in the southern fringes of the Atacama desert, 160 km north of
The observatory went into operation in 1969 and quickly became the
best optical observatory of the world.
In its heyday, 16 telescopes were in service.
Starting in the 1970s, La Silla became the “home observatory”
for scientists of the Bogenhausen observatory.
The boom continued in the following decades and today the observatory
ranks among the best in the world.
Apart from the established highly sophisticated stellar astrophysical
analyses (stellar winds, chemical evolution of galaxies), unsolved
issues regarding the large-scale structure of the universe, the origin,
evolution, and interaction of galaxies and their chemical properties
are being investigated.
This includes the analysis of galactic black holes and the
investigation of dark matter by means of gravitational lenses.
Numerical simulations using supercomputers have become an essential
means of describing complex physical phenomena in the universe, and
the observatory has added simulations of the origin and the evolution
of the galaxies, the formation and dynamics of molecular clouds and
the formation of stars and planets to its scientific program.
Specific radiation phenomena that result from the interaction of cosmic
plasmas with electric and magnetic fields are also being studied.
These investigations range from the physics of aurorae and solar
flares to as-yet poorly understood radiation bursts linked to black
holes and pulsars, up to questions regarding the origin of cosmic
The four 8.2-m telescopes of the VLT on the 2635-m-high Cerro
Paranal in the Chilean Atacama desert, approximately 130 km south
The roof of the control building, from which all telescopes are
monitored and observations are performed, can be seen in the back on
the left hand side, at the edge of the summit plateau.
To the right of this are the telescopes number 1 and 2, at which the
two FORS instruments are deployed, in whose development the observatory
has been instrumental.
The FORS2 instrument (yellow) in the Cassegrain focus of VLT telescope
number 2, pointed nearly horizontally for testing purposes.
In spite of its huge dimensions
(height: 3 m, diameter: 1.6 m (without the four attached gray
electronics enclosures), weight: 2.5 tons), the instrument is dwarfed
by the support structure of the 8.2-m main mirror.
New developments in instrumentation have been pursued from the
Scientific instrumentation of large telescopes has become increasingly
sophisticated, requiring synergies of scientific and technical
know-how of several institutes as well as cooperation with industry
to successfully plan, build, and deploy such instruments.
Furthermore, these projects require third-party funding (on the scale
of millions of Euros) essentially by the Research Program of the
Federal Ministry of Education and Research (BMBF), allowing additional
staff to be hired and non-personnel-costs to be financed.
Due to its reputation, the USM was and is successful in raising funds
and has been a valued partner in national and international research
consortia and has thus been involved in important instrumentation
projects for over 20 years.
Innovative instruments are being built in close cooperation with
national institutes, but also with institutes in Great Britain,
the Netherlands, Italy, the USA, and China.
These instruments are being used in large telescopes throughout
the world, providing the prerequisites for making new scientific
Among these instruments are the two combi-instruments FORS1 and FORS2
carrying the main burden of observations (direct imaging, multiple
simultaneous spectroscopy, polarimetry) at ESO’s Very Large Telescope
(VLT) on Paranal/Chile since the end of the 1990s.
Until now, three scientific papers a week are published in research
journals based on data gained with the FORS instruments.
Furthermore, the KMOS infrared spectrograph is under construction
and is likely to begin operations in 2011 as a second-generation
instrument at the VLT.
KMOS will deliver spatially resolved spectral information (196 spectra
per object) of up to 24 remote galaxies simultaneously.
KMOS will thus provide insight into the processes involved in the
origin and evolution of galaxies.
Last but not least, the USM will be involved in the construction of
the camera MICADO for the E-ELT project (European Extremely Large
Telescope) currently in the planning stage.
From 2021 onwards this really enormous telescope with a diameter
of 39 meters will allow us to look back to the era of the formation
of the first stars and galaxies.
In this picture of the VLT complex the smaller, darker dome of the
2.6-m VLT Survey Telescope can bee seen between VLT domes
number 3 and 4.
For this survey telescope, in cooperation with other institutes in the
Netherlands, in Italy and in Germany, the observatory has delivered
one of the biggest CCD-cameras ever built.
The camera will be used for large-scale surveys of the sky, with
detailed observations using VLT instruments following up for objects
Model of the E-ELT (European Extremely Large Telescope).
The light-gathering capacity of its 39-m mirror will permit imaging
the formation of the primordial stars and galaxies for the first time.
Due to the finite speed of light, telescopes are time machines that
allow looking back into the past of our universe in order to study it.
As part of an international consortium, in 2007 the observatory has
been awarded the contract for the design of the first camera (MICADO)
with which the E-ELT is scheduled to begin operations 2021 in Chile.
The telescope will weigh 5500 tons and will be housed in a dome
whose dimensions (height:
64 m, diameter:
77 m) will far surpass those of the nave of the Frauenkirche in Munich.
The USM also has its own observatory on the summit of the 1838-m-high
Wendelstein, about 75 km southeast of Munich.
There, observations of the solar corona, prominences, and sunspots
had been carried out for several decades as part of an international
network of solar observatories.
In the mid-1980s, these observations were terminated and the switch
to night-time astronomy was made.
Between 1989 and 2007, a 0.8-m telescope was operated, and,
using instruments built at the USM, ambitious stellar photometric
observation programs were carried out (some simultaneously with
satellite measurements or spectroscopic observations at international
large telescopes), as well as pixel-lensing experiments towards the
Andromeda galaxy for detecting macroscopic dark matter.
The need for a modern, larger telescope of the 2-m class, allowing
such programs to be run even more efficiently, became increasingly
clear over the years.
With 130 clear nights per year, mostly with good atmospheric
transmittance and a so-called “seeing” comparable to that on
Paranal/Chile, the Wendelstein is indeed a good location for such a
state-of-the-art telescope costing 8 million Euros.
In 2006, the Bavarian Ministry for Science, Research and Art approved
the project and the new telescope will come into operation in 2011.
The USM is also involved in the operation of the 9-m Hobby-Eberly
telescope of the McDonald observatory in western Texas, where it has
operated since 1998 and is used solely for spectroscopic analyses.
One of its spectrographs was conceived in cooperation with US partners
and built in Bogenhausen.
The observatory on Mount Wendelstein has been part of the University
Observatory since 1949.
Built originally as a solar observatory in 1941 for military purposes,
it has served exclusively for night-time observation since 1989.
At present, the Wendelstein observatory is undergoing major
construction work in preparation for the deployment of a 2-m telescope,
which is scheduled to begin operation in 2011.
Together with the Max Planck Institutes for Astrophysics and
Extraterrestrial Physics and the ESO administration in Garching,
the USM in Bogenhausen covers nearly the whole range of astrophysical
Having almost 1000 employees, these institutes constitute the largest
center of astronomy in Germany and one of the biggest and most active
in the world.
Cooperation between the institutes has been intensified over a
period of decades, and today they collaborate closely on a number of
scientific and technical projects.
The international reputation has also attracted an increasing number
of students who appreciate the wide range of scientific opportunities
More than 30% of the physics students at the
Ludwig-Maximilians-Universität München choose astrophysics as an
elective course for their Diploma examination, and the number of
students who choose a theoretical or experimental problem from modern
astrophysics as a PhD thesis is steadily increasing.
In the year 2000, on initiative of the Max-Planck-Gesellschaft,
the institutes founded the International Max Planck Research
School on Astrophysics (IMPRS) at the LMU with the aim of offering
highly qualified and motivated students from all over the world the
opportunity to profit from the excellent scientific environment in
Munich in acquiring a PhD.
The establishment of the school was an immediate success:
at present, 70 students are working on their PhD theses at the
Applications from motivated students, mostly from abroad, are so
numerous that only 20% of those who apply can be accepted.
The crab nebula at a distance of 6000 light-years is the result of
a supernova explosion that took place in our Galaxy in 1054.
In its center is the remnant of the exploded star, a neutron star
with a diameter of only a few kilometers.
The gas ejected during the explosion is still hurtling through space
with a speed of over 4 million km/h.
This electronic image was taken for test purposes by the FORS team
in November 1999 using FORS2 at VLT telescope number 2.
This electronic image (FORS Deep Field) represents one of the
farthest views towards the edge of our observable universe ever taken
from the ground.
The image is the result of a total integration time of more than
20 hours and shows a field of view corresponding to only 7% of the
surface of the full moon.
Some 10 000 mostly far-away galaxies of different types and shapes
can be identified.
Before being captured by FORS1 at VLT telescope number 1 in the autumn
of 1999, the light from these galaxies had been travelling for up to
10 billion years, thus being much older than our own solar system.
In the first round of an initiative started in 2005 to bolster science
at German universities, the USM played a leading role in submitting
the proposal and setting up the Excellence Cluster for fundamental
physics entitled “Origin and Structure of the Universe”.
In this project astrophysicists join together with nuclear and particle
physicists in the quest to find answers to the most important unsolved
questions of modern science which link the smallest and the largest
scales in the cosmos:
the innermost structure of matter, space and time, the origin and
nature of the four fundamental forces as well as the structure,
geometry and evolution of the elemental abundances in the universe.
Among other things, ideas about dark matter, dark energy, supersymmetry
and quantum gravity are investigated and new laws in physics are
The E-cluster is initially supported with 6.5 million Euros per year
up to 2011 and has led to a considerable increase in staff at the USM.
The commitment and reputation of the Cluster member has certainly
contributed to the title of “Elite University” being awarded to
Thus, the Observatory in Bogenhausen has proved for many years that it
is able and willing to accept the challenges of modern astrophysics
and to play an important role in cooperative international efforts
to study the origin, structure, and development of our universe.
Dr. Reinhold Häfner, University Observatory Munich, January 2009.
Die Attribute der Bayerischen Akademie der
Münchener Historische Studien, Abteilung Bayerische Geschichte, Band 8,
R. Häfner, R. Riekher:
Die Pioniere der Sternspektroskopie. Die stellarspektroskopischen
Untersuchungen von Fraunhofer (1816–1820) und Lamont (1836).
In: Acta Historica Astronomiae Vol. 18, 137–165 (2003)
Die Universitäts-Sternwarte München im Wandel ihrer Geschichte.
R. Häfner, H. Soffel (Hg.):
Johann von Lamont 1805–1879, Leben und Werk.
Astronomie in Bayern 1914–1945.
University Observatory Munich: Nr. 1–5, 11, 13
European Southern Observatory: Nr. 6–10, 12, 14