2023-01-30 | 130 years of spectroheliograms at Paris-Meudon observatories (1892-2022) | BASS2000 |
For his part, Henri Deslandres initiated imaging spectroscopy in 1892 at Paris observatory. He invented, concurrently with George Hale in Kenwood (USA) but quite independently, the spectroheliograph designed for monochromatic imagery of the solar atmosphere. Deslandres developed two kinds of spectrographs: the "spectrohéliographe des formes", i.e. the narrow bandpass instrument to reveal chromospheric structures (such as filaments, prominences, plages and active regions); and the "spectrohéliographe des vitesses", i.e. the section spectroheliograph to record line profiles of cross sections of the Sun with a 20'-30' spatial step. This second apparatus was intended to measure the velocities (more exactly the Dopplershifts) of dynamic features. Deslandres moved to Meudon in 1898 with his instruments and tested various combinations, in order to improve the spectral and spatial resolutions, leading to the final large quadruple spectroheliograph in 1908. CaII K systematic observations started at this date and were followed in 1909 by Hα.
The service was organized by Lucien d’Azambuja and continues today. Optical and mechanical parts were revisited in 1989 and the digital technology was introduced in 2002. Full line profiles are registered for all pixels of the Sun since 2018, so that the instrument produces now data-cubes. The collection is one of the longest available (more than 100 000 observations). It contains sporadic images from 1893 to 1907 (during the development phase) and systematic observations along 10 solar cycles since 1908, in Hα and CaII K lines.
This paper summarizes 130 years of observations, instrumental research and technical advances.
2021-06-11 | Video of the partial eclipse of 10 June 2021 | BASS2000 | Read ... |
2020-04-17 | License for BASS2000 data | BASS2000 | Read ... |
2019-12-06 | Data and instruments guides updated | BASS2000 | Read ... |
2019-11-26 | Data access available! | BASS2000 | Read ... |
2019-11-21 | Data access suspended until 2019-11-27 | BASS2000 | Read ... |
2019-05-29 | 1919 eclipse! | Bass2000 | Read ... |
2018-12-17 | F.A.Q. available! | Bass2000 | Read ... |
2018-03-21 | Latest data from Heliophysics Features Catalogue | Bass2000 | Read ... |
2018-03-06 | How to contact BASS2000? | Bass2000 | Read ... |
2017-09-01 | Migration of BASS2000 servers | Bass2000 | Read ... |
2017-06-28 | SPECTROCAM: new camera for the Spectroheliograph of Meudon | Bass2000 | Read ... |
2017-03-09 | Synoptic data from year 1919 | BASS2000 | Read ... |
2016-11-15 | New Webcam available | Bass2000 | Read ... |
2016-07-25 | Solar Spectrum tool updated | C Renié | Read ... |
2015-03-11 | Link to HELIO Features Catalog | C. Renié | Read ... |
2015-02-23 | Status of Nancay RadioHeliograph | NRH team | Read ... |
2014-02-25 | Update of the ephemerids and solar grid service | C. Renie | Read ... |
2013-08-07 | Stopped or degraded NRH observations | A. Kerdraon | Read ... |
2013-02-20 | New Educational resources | C. Renié | Read ... |
2012-12-06 | New observations at Meudon Solar Tower | J. Aboudarham | Read ... |
2008-08-08 | New version! | Read ... |
2008-08-01 | Movies from CLIMSO | Read ... |
2008-06-19 | HeI observations from CLIMSO | Read ... |
2008-01-22 | Green continuum images from Meudon Heliograph | Read ... |
2007-11-09 | New data from Meudon Heliograph | Read ... |
2007-10-18 | CaK observations from CLIMSO | Read ... |
2007-06-15 | New data from CLIMSO | Read ... |
2006-02-20 | Solar Spectrum in UV | C. Renié | Read ... |
2005-11-10 | Nancay Total Radio Flux Antenna | A. Kerdraon | Read ... |
2004-08-31 | Update of the Web Site | C. Renié | Read ... |
2004-05-27 | Venus transit - June 8, 2004 | J-M Malherbe | Read ... |
2003-06-02 | May 31, 2003: pictures of the solar eclipse | - | Read ... |
2003-04-25 | Mercury Transit - May 7, 2003 | J-M Malherbe | Read ... |
2003-02-28 | EGSO software for Meudon spectroheliograph FITS data | N.Fuller | Read ... |
2003-01-28 | New Meudon's webcam: White light | J-M Malherbe | Read ... |
2002-10-02 | Welcome to the new BASS2000 Solar Survey database | J. Aboudarham | Read ... |