Quasar spectrum with a Lisa or an Alpy
Quasar spectrum with a Lisa or an AlpyBy Olivier GardeThe Lisa and Alpy spectrographs are particularly suited to the study weak objects. During the Spectro Party 2018 at OHP, we were able to realize the spectrum of a quasar of magnitude V = 16.52 with a 355mm...
Planetary nebulae confirmation
Planetary nebulae confirmationBy Olivier Garde Recommanded equipment : Alpy, Lisa Time : about 4 h For several years, amateur astronomers have been discovering probable planetary nebula candidates thanks to their own images or by scrutinizing professional surveys...
Making Science with an Alpy
Making Science with an Alpy The last paper in Astronomy & Astrophysics magazine (A&A) “New outburst of the symbiotic nova AG Peg after 165 years “ is based on spectra collected by observers from all around the world (12 nations represented) with Hubble,...
How to measure the redshift of a galaxy ?
How to measure the redshift of a galaxy ? Recommanded equipment : Alpy, Lisa, Star Analyser Time : 1 to 4 h Low resolution spectroscopes are particularly well suited to the study of distant galaxies such as Seyfert galaxies or Quasars. We can easily calculate their...
Symbiotics stars
Symbiotics stars Recommended equipment : Star Analyser, Lhires III, eShel, Alpy, Lisa Time : one night or a life time ! Summary Symbiotic stars are interacting binary red giant & hot stars. The red giant loose material which is accreted by the hot star (main...
Del Sco : 2011 campaign for periastron
Del Sco : 2011 campaign for periastron Be stars are hot, non supergiants stars whose spectra have shown or still show spectral emission in Balmer line – typically Halpha. Those emissions comes from material around the star – often an equatorial disk or...
Beta Lyrae – Shelyak !
Beta Lyrae – Shelyak ! Well… beta Lyrae is a special star for us as its arabic name is Shelyak, the origin of the Shelyak Instruments company name. Few years ago, we spent couple of week studying this star spectroscopically. This is a Be star (see article...
Be stars
Be stars Recommended equipment : Lhires III, eShel, Lisa, Alpy Time : one evening to a life time ! Abstract Classical Be stars are non supergiant B-type stars that exhibit or have exhibit emission lines over the photospheric spectrum. This article review common...
Beta Aurigae spectroscopic binary
Beta Aurigae spectroscopic binary Recommended equipment : Lhires III, eShel Time : several observing nights Summary Grâce à la haute résolution du Lhires III, il est possible de séparer de nombreuses étoiles binaires spectroscopiques. Ces étoiles, qui...
RV (Radial Velocity)
RV (Radial Velocity) Recommended equipment : eShel, Lhires III Time : 1 h Stars are moving into space and their spectra appear shifted compared to the same lines in laboratory. Exemple here is SAO104807 which is moving toward us at a speed of 100 km/Sec and SAP112958...
Lithium star : 59 Vir
Lithium star : 59 Vir Recommended equipment : eShel, Lhires III Time : one evening (acquisition) 59 Vir is a G0V type star, close to solar spectral type. But its spectrum display a stroing Li I (6708) absorption line. This star is rather young and lithium will...
Measure star temperature
Measure star temperature Recommended equipment : Lhires III, eShel, Lisa, Alpy, Star Analyser Time : 4h French philosopher Auguste Compte (1798-1857) became very famous when he wrote in 1835 about stars: “… we will never know, by any mean, chemical...
Spectral classification (high resolution)
Spectral classification (high resolution) Recommended equipment : Lhires III, eShel Durée : 1 night Introduction Low resolution spectroscopy allows to classify stars and measure their effective temperature. But this method is limited and hgih resolution spectroscopy...
Spectral classification (low resolution)
Spectral classification (low resolution) Recommended equipment : Lhires III, Star Analyser, Alpy, LISA, eShel Time : 1 night Spectroscopy is a great tool to compare stars between themselves and determine their spectral class – thus their effective temperature....