Terra-Astronomy
(from celestial signs to celestial sciences)

Recent Highlight
Our projects
Our team
Our collaborations
Our publications
Student thesis work
Teaching and Outreach
Conferences and workshops

We use terrestrial archives (historical written, oral, and drawings as well as radioisotopes on Earth) to study effects of variable solar activity and nearby stellar explosions on Earth: The long-term irradiance variation of our Sun affects atmosphere, climate, and biosphere of the Earth. Nearby explosive events (like strong flares on our Sun, normal stars, and neutron stars, novae and supernovae, as well as gamma-ray bursts) deposit high-energy emission into the Earth atmosphere. Both, the steady flux of Galactic cosmic rays into the Solar system – modulated by the variable solar wind – and the transient flux from high-energy events generate radioisotopes (like ¹⁰Be, ¹⁴C) on Earth, so that they can be used to study such effects.

One can reconstruct solar activity and can identify relevant stellar explosions over the last few millenia using both radioisotopes on Earth and historical observational reports about aurorae, comets, sunspots, (super-)novae, etc. from all civilizations on Earth: While European and Eastern Asian reports have been studied already, historical documents from Arabia were not considered much, yet. Terra-Astronomy is universal and trans-disciplinary. European, Byzantine, and East Asian reports date back up to 2000–3000 years. One can try to use Babylonian, Assyrian, Hithite, and Egyptian reports to go back even further.

The ultimate goals are (i) to understand solar activity variations well enough for sufficiently precise expectations of solar activity for the next few years and decades (space weather and Earth climate), and (ii) to evaluate possible effects of nearby explosions on climate and evolution on Earth in the past.

In an additional, complimentary project part, we investigate the pre-historic epoch with neutron stars and runaway stars – both the last 100,000 years with supernova remnants and even the last few million years.

The Earth is truely a celestial body, and it is subject to variable emission from the Sun and from many other celestial objects.

In comparison to similar fields...

• Terra-Astronomy is also a study of space weather: it covers several millennia and uses historical archives, but it includes studying space weather (solar storms in the near Earth environment like the low-Earth orbits of satellites and astronauts) on all time-scales;

• it is not just a study of catastrophic events (like asteroids hitting Earth), but instead studies variations of emission on all time-scales, and it includes explosive events;

• it is a study of solar-terrestrial relations and extends this subject to all other relevant astrophysical phenomena;

• it is not just a natural science, but a trans-displiplinary endeavour with science, humanities, and arts, e.g. the interpretation of celestial observations and their impact on history;

• it is applied historical astronomy with the reconstruction of naked-eye astronomy, and also involves terrestrial radioisotope archives and new current astronomical (follow-up) observations; and

• it is not only about history of science, because we use historical archives for advancing certain fields of astrophysics – yet, we also study the history of astronomy.

Astronomy is one of very few scientific disciplines, where historical observations and data – as reported in manuscripts of previous centuries and millennia (partly also oral tradition, cave paintings and drawings) – can be used not only to study the history of this field (and to constrain chronologies in general), but also to obtain new results at the forefront of actual astrophysical science: Solar activity, space weather, supernovae, comets, etc.

Our project is feasible for the last few millenia, namely since reports were written and preserved.

This project has a strong potential for public awareness on our dependance on external factors and worldwide citizen science with non-professional historians and high-school students searching for more reports about celestial events in their local chronicles. Terra-Astronomy is highly trans-disciplinary: Astronomy, solar and plasma physics, geophysics (Earth magnetic field), biology and meteorology (effects on atmosphere, weather, biosphere), history, languages, cultural impact of astronomical observations on civilizations, etc.

While astronomy so far was the study of everything in the Universe but Earth, Terra-Astronomy also studies Terra (planet Earth) with astrophysical methods: Planet Earth – for us – is an important part of the Universe.

Recent Highlight:

• Publication in MNRAS

Our projects:

• Solar activity proxies for the pre-telescopic epoch

• Completeness of historical observations

• Solar activity in the Maunder minimum

• Drawings of celestial observations in historical chronicles

• Cultural relevance of halo sightings

• Historical supernovae in Arabic documents

• Super-flares on Sun-like stars

• Comet orbit reconstruction with historical observations

• Colors of stars
   

Our team:

• PI: Ralph Neuhäuser

• Co-PI: Dagmar L. Neuhäuser (proxies and patterns; text analysis and critique; cultural relevance)

• Valeri Hambaryan (high-energy astrophysics and variability)

• Kai-Uwe Michel (PhD student, high-mass X-ray binaries)

• Markus Mugrauer (naked-eye astronomy reconstruction, e.g. historical comet orbits)

• Daniela Luge (historical texts in Latin and Greek)
   

Our collaborations:

• Rainer Arlt, AIP Potsdam,
  Sunspots

• Jesse Chapman, U Berkeley, USA
  East-Asian celestial observations

• Matteo Cosci, U Ca'Foscari Venezia, Italy
  Observations of supernova SN 1604

• Amir Harrak, U Toronto, Canada,
  Syriac celestial observations

• Paul Kunitzsch, LMU München (deceased 2020),
  Arabic celestial observations

• Wafiq Rada, Babylon, Iraq (deceased 2015),
  Arabic celestial observations

• Pouyan Rezvani, PAL, Bavarian Academy of Sciences
  https://ptolemaeus.badw.de/team/46
  Arabic and Persian celestial observations

• Petra Schmidl, Uni Erlangen-Nürnberg
  Arabic and Persian celestial observations

• Guillermo Torres, Harvard and Smithsonian, Boston, USA
  Stellar astrophysics
   

Our publications:

• Neuhäuser R. & Neuhäuser D.L., Mugrauer M., Luge D., Chapman J. (2024): "The Mira discovery problem - Observations by David Fabricius in 1596 and 1609 (and by others before?): Positional accuracy, brightness, color index, and period", Astron. Notes 345, id. e20230131
  https://onlinelibrary.wiley.com/doi/10.1002/asna.20230131

• Neuhäuser R. & Neuhäuser D.L. (2024): "Occultation records in the Royal Frankish Annals for A.D. 807: Knowledge transfer from Arabia to Frankia?", J. Hist. Astron. 55, 364-395
  https://journals.sagepub.com/doi/epub/10.1177/00218286241238731 (unpublished short appendix on the travel of the mixed delegation here)

• Neuhäuser D.L., Neuhäuser R. (2023): "Les couleurs de Betelgeuse", L'Astronomie 170, p. 38-45

• Neuhäuser D.L., Neuhäuser R. (2023): "The shifting hues of Betelgeuse", Astronomy & Geophysics 64, p. 1.38-1.42, PDF

• Neuhäuser D.L. (2023): "Beteigeuze - Vom Gelben zum Roten Überriesen", Sterne und Weltraum 1/2023, p. 23-25

• Neuhäuser R., Torres, G., Mugrauer, M., Neuhäuser D.L., Chapman, J., Luge, D., Cosci, M. (2022): "Colour evolution of Betelgeuse and Antares over two millennia, derived from historical records, as a new constraint on mass and age", Mon. Not. R. Astron. Soc., 516, 693–719, PDF

• Neuhäuser R., Neuhäuser D.L. (2022): "Arguments for a comet as cause of the Hopewell airburst are unsubstantiated", Nature Scientific Reports 12, 12090, PDF
  https://www.nature.com/articles/s41598-022-16211-5
  reply by Tankersley et al. here – 2nd Matters Arising here — original article retracted

• Wagner D., Neuhäuser R., Arlt R. (2022): "Bayesian approach for auroral oval reconstruction from ground-based observations", J. Atmo. Solar-Terr. Physics 228, 105824
  https://doi.org/10.1016/j.jastp.2022.105824

• Neuhäuser R., Neuhäuser D.L. (2021): "Critical comments on publications by S. Hoffmann and N. Vogt on historical novae/supernovae and their candidates", Astron. Notes 342, 675–695, PDF
  https://doi.org/10.1002/asna.202113872

• Neuhäuser D.L., Neuhäuser R., Mugrauer M., Harrak A., Chapman J. (2021): "Orbit determination just from historical observations? Test case: The comet of 760 CE is identified as 1P/Halley", Icarus 364, 114278, PDF
  https://doi.org/10.1016/j.icarus.2020.114278

• Neuhäuser R., Neuhäuser D.L., Chapman J. (2021): "Novae, supernovae, or something else? – (Super-)nova highlights from Hoffmann & Vogt are quite certainly comets (AD 668 and 891)", Mon. Not. R. Astron. Soc. 501, L1–L6, PDF
  https://ui.adsabs.harvard.edu/abs/2021MNRAS.501L...1N/abstract

• Neuhäuser R., Geymeier M., Arlt R., Chapman, J. (2020): "Comparison of telescopic and naked-eye sunspots for the very small spots on February 15, 1900 and January 30, 1911", Astron. Notes 341, 366
  https://ui.adsabs.harvard.edu/abs/2020AN....341..366N/abstract

• Neuhäuser R., Neuhäuser D.L., Posch T. (2020): "Terra-Astronomy – Understanding historical observations to study transient phenomena", in: Lago T. (Ed.) Astronomy in Focus – Proc. Focus Meetings IAU GA (held August 2018, Vienna, Austria), Cambridge University Press, 145–147, PDF

• Wagner, D. & Neuhäuser, R. (2019): "Variation of the auroral oval size and offset for different magnetic activity levels described by the Kp-index", Astron. Notes 340, 483–493
  https://ui.adsabs.harvard.edu/abs/2019AN....340..483W/abstract

• Neuhäuser, R., Kunitzsch, P., Mugrauer, M., Luge, D. and van Gent, R. (2018): Tycho Brahe, Abu Ma^cshar, und der Komet hinter Venus. In: Wolfschmidt, G. (ed.): Astronomie im Ostseeraum. Astronomy in the Baltic. Proceedings der Tagung des Arbeitskreises Astronomiegeschichte in der Astronomischen Gesellschaft 2015 (held in Kiel, Sept 2015). Nuncius Hamburgensis 38, tredition, Hamburg, 161–173

• Neuhäuser D.L., Neuhäuser R., Harrak, A. (2018): "Reports and drawings of celestial observations in the 8th century Syriac Chronicle of Zuqnin (auroral and meteoritic phenomena)", Journal of the Canadian Society for Syriac Studies 18, 67-90, PDF

• Neuhäuser R., Arlt R., Richter S. (2018): "Reconstructed sunspot positions in the Maunder Minimum based on the correspondence of Gottfried Kirch", Astron. Notes 339, 219-267, PDF
  http://adsabs.harvard.edu/abs/2018AN....339..219N

• Neuhäuser D.L. & Neuhäuser R. (2018): "On the perspective in and dating of Munch's Screaming Clouds - comments on the article by Fikke et al., 2017", Weather (Royal Meteorological Society Journal) 73(4), 133-134, PDF
  http://onlinelibrary.wiley.com/doi/10.1002/wea.3172/full
  with a response by Fikke & Nordli 2018

• Neuhäuser D.L., Neuhäuser R., Chapman J. (2018): "New sunspots and aurorae in the historical Chinese text corpus? Comments on uncritical digital search applications", Astron. Notes 339, 10-29,
  arXiv:1711.05132
  http://onlinelibrary.wiley.com/doi/10.1002/asna.201713390/full

• Neuhäuser R., Neuhäuser D.L., Rada W., Chapman J., Luge, D., Kunitzsch P. (2017): "Interpretation of the historic Yemeni reports of supernova SN 1006: early discovery in mid-April 1006 ?", Astron. Notes 338, 8-18,
  http://adsabs.harvard.edu/abs/2017AN....338....8N

• Neuhäuser R., Ehrig-Eggert C., Kunitzsch P. (2017): "An Arabic report about supernova 1006 by Ibn Sina (Avicenna)". Astron. Notes 338, 19-25,
  http://adsabs.harvard.edu/abs/2017AN....338...19N

• Neuhäuser, R., Rada, W., Kunitzsch, P. and Neuhäuser, D.L. (2016): Arabic Reports about Supernovae 1604 and 1572 in Rawḥ al-Rūḥ by ^cĪsā b. Luṭf Allāh from Yemen. J. Hist. Astron. 47, 359–374,
  http://adsabs.harvard.edu/abs/2016JHA....47..359N, PDF

• Neuhäuser R. & Neuhäuser D.L. (2016): "Teleskopische Beobachtungen von Sonnenflecken durch Simon Marius in den Jahren 1611 bis 1619". In: Gaab H. & Leich P. (Eds.): Simon Marius und seine Forschung, Acta Historica Astronomiae, Vol. 57, Akademische Verlagsanstalt, Leipzig, 179–198,
  www.simon-marius.net/pix/content/4/Neuhaeuser_Teleskopische-Beobachtungen-von-Sonnenflecken_2016.pdf

• Neuhäuser R., Kunitzsch P., Mugrauer M., Luge D., van Gent R. (2016): "Tycho Brahe, Abu Ma^cshar, and the comet beyond Venus (ninth century A.D.)". J. Hist. Astron. 47, 136-158, PDF

• Neuhäuser R. & Neuhäuser D.L. (2016): "Sunspot numbers based on historic records in the 1610s – early telescopic observations by Simon Marius and others". Astron. Notes 337, 581-620
  http://adsabs.harvard.edu/abs/2016AN....337..581N

• Neuhäuser R. & Neuhäuser D.L. (2015): Variations of 14-C around AD 775 and AD 1795 – due to solar activity. Astron. Notes 336, 930-954
  http://adsabs.harvard.edu/abs/2015AN....336..930N

• Neuhäuser D.L. & Neuhäuser R. (2015): "A red cross appeared in the sky" and other celestial signs: Presumable European aurorae in the mid AD 770s were halo displays. Astron. Notes 336, 913-929
  http://adsabs.harvard.edu/abs/2015AN....336..913N, Preprint on arXiv.org

• Neuhäuser R., Arlt R., Pfitzner E., Richter S. (2015): Newly found sunspot observations by Peter Becker from Rostock for 1708, 1709, and 1710. Astron. Notes 336, 623-633
  http://adsabs.harvard.edu/abs/2015AN....336..623N

• Chapman J., Neuhäuser D.L., Neuhäuser R., Csikszentmihalyi M. (2015): A review of East Asian reports of aurorae and comets circa AD 775. Astron. Notes 336, 530-544
  http://adsabs.harvard.edu/abs/2015AN....336..530C

• Neuhäuser R. & Neuhäuser D.L. (2015): Solar activity around AD 775 from aurorae and radiocarbon. Astron. Notes 336, 225-248
  http://adsabs.harvard.edu/abs/2015AN....336..225N

• Rada W. & Neuhäuser R. (2015): Supernova SN 1006 in two historic Yemeni reports. Astron. Notes 336, 249-257
  http://adsabs.harvard.edu/abs/2015AN....336..249R

• Neuhäuser D.L. & Neuhäuser R., (2015): Himmelspredigt - Haloerscheinungen in der Reformationszeit. In: Salatowsky, S. & Lotze, K.H. (Eds.) Katalog zur Ausstellung "Himmelsspektakel. Astronomie im Protestantismus der Frühen Neuzeit". Veröffentlichungen der Forschungsbibliothek Gotha, Vol. 52, Gotha 2015, 12-23, PDF

• Neuhäuser, R., Kunitzsch, P. and Rada, W. (2015): Arabic observations of historic supernovae. In: Wolfschmidt, G. (Ed.): Astronomie in Franken. Von den Anfängen bis zur modernen Astrophysik. 125 Jahre Dr. Karl Remeis-Sternwarte Bamberg (1889). Tagung des Arbeitskreises Astronomiegeschichte in der Astronomischen Gesellschaft 2014. Nuncius Hamburgensis 31, tredition, Hamburg, 519–559.

• Neuhäuser D.L. & Neuhäuser R. (2014): In den Himmeln erschien ein rotes Kruzifix: Halo-Code und Halo-Vergessenheit. In: Wolfschmidt, G. (Ed.): Proc. Der Himmel über Tübingen – Barocksternwarten – Landesvermessung – Hochenergieastrophysik. Tagung des Arbeitskreises Astronomiegeschichte in der Astronomischen Gesellschaft 2013, Nuncius Hamburgensis 28, tredition, Hamburg, 470-518, PDF

• Neuhäuser R. & Neuhäuser D.L. (2014): Historische Beobachtungen als Schlüssel für das Verständnis von Radiocarbon-Schwankungen. In: Wolfschmidt, G. (Ed.): Proc. Der Himmel über Tübingen – Barocksternwarten – Landesvermessung – Hochenergieastrophysik. Tagung des Arbeitskreises Astronomiegeschichte in der Astronomischen Gesellschaft 2013, Nuncius Hamburgensis 28, tredition, Hamburg, 465-469, PDF

• Neuhäuser R. & Kunitzsch P. (2014): A transient event in AD 775 reported by al-Ṭabarī: A bolide – not a nova, supernova, or kilonova. Astron. Notes 335, 968-980
  http://adsabs.harvard.edu/abs/2014AN....335..968N

• Chapman J., Csikszentmihalyi M., Neuhäuser R. (2014): The Chinese comet observation in AD 773 January. Astron. Notes 335, 964-967
  http://adsabs.harvard.edu/abs/2014AN....335..964C

• Neuhäuser R. & Hambaryan V.V. (2014): A solar super-flare as cause for the ¹⁴C variation in AD 774/5 ?. Astron. Notes 335, 949-963
  http://adsabs.harvard.edu/abs/2014AN....335..949N

• Kitze M., Neuhäuser R., Hambaryan V.V., Ginski, C. (2014): Superflares on the slowly rotating solar type stars KIC10524994 and KIC07133671. Mon. Not. R. Astron. Soc. 442, 3769-3776
  http://adsabs.harvard.edu/abs/2014MNRAS.442.3769K

• Hambaryan V.V. & Neuhäuser R. (2013): A Galactic short gamma-ray burst as cause for the ¹⁴C peak in AD 774/5. Mon. Not. R. Astron. Soc. 430, 32-36
  http://adsabs.harvard.edu/abs/2013MNRAS.430...32H

Student thesis work:

• Jonna Schickhoff, Bachelor thesis:
  Numbering of stars in ancient Chinese asterisms (ongoing)

• Kai-Uwe Michel, PhD thesis:
  High-mass X-ray binaries in nearby associations (ongoing)

• Phillip Pukallus, Bachelor thesis:
  Earth rotation (Delta T) in AD 840 and 1185 (2022)

• Malina Jürgensen, Bachelor thesis:
  Celestial observations in Gregor of Tours' work (2022)

• Oliver Lux, PhD thesis:
  Runaway stars in nearby young supernova remnants (2021)

• Daniel Wagner, PhD thesis:
  Reconstruction of aurora oval and geomagnetic pole from ground-based aurorae (2020)

• Michael Geymeier, Master thesis:
  Comparison of SN 1604 light curve with modern supernovae (2019)

• Saskia Schlagenhauf, Bachelor thesis:
  Historical meteor showers (2019)

• Manfred Kitze, PhD thesis:
  Flares on Sun-like stars in Kepler data (2017)

• Marie Sophie Zeidler, Bachelor thesis:
  Historical Novae (2016)

• Cora Preiß, Bachelor thesis:
  Aurorae in the Oort, Wolf, and Spörer Grand Minima (2015)

• Jan Sende, Master thesis:
  Cosmic-ray impacts on Earth and radionuclei production (2015)

• Susanne Richter, Master thesis:
  Solar activity proxies in the Maunder Minimum in letters to and from Kirch (2015)

• Danny Hässner, Bachelor thesis:
  Two-dimensional sunspot counting from the butterfly diagram (2015)

• Tamara Zehe, Bachelor thesis:
  Location of geo-magnetic pole from aurorae (2014)

• Markus Drüke, Bachelor thesis:
  Solar activity from C-14 (2014)
   

Teaching and Outreach:

• Lecture with exercises and seminar on "Terra-Astronomy" (Summer 2023)

• Lecture with exercises and seminar on "Terra-Astronomy" (Summer 2021)

• Lecture with exercises and seminar on "History of Astronomy" (Fall 2020/21)

• Lecture with exercises and seminar on "Terra-Astronomy" (Summer 2019)

• Advanced seminar on "Novae and Supernovae" (Fall 2018/19): schedule

• Lecture with exercises and seminar on "Terra-Astronomy" (Summer 2017)

• Advanced seminar on "Historical Astronomy" (Fall 2016/17): schedule

• Advanced seminar on "Stellar variability and Terra Astronomy" (Fall 2015/16)

• Ausstellung Himmelsspektakel Gotha with participation by us (Summer 2015): PDF

• Lecture with exercises and seminar on "Terra-Astronomy" (Summer 2015)

• Advanced seminar on "Solar activity reconstruction" (Fall 2014/15): schedule
   

 Conferences and workshops:

• Lorentz-Center Workshop October 2019: "Historical Supernovae, Novae and Other Transient Events" (SOC: J. McAllister, R. Neuhäuser, J. Vink, P. Zhou): link

• Focus Meeting 5 at General Assembly of the International Astronomical Union, August 2018: link

• Session at Deutscher Orientalisten-Tag (DOT), September 2017: schedule