Spectroscopic Atlas for Amateur Astronomers 1 Spectroscopic Atlas for Amateur Astronomers A Guide to the Stellar Spectral Classes Richard Walker Version 3.0 03/2012 Spectroscopic Atlas for Amateur Astronomers 2 Table of Contents 1 Introduction ....................................................................................................................... 7 2 Selection, Preparation and Presentation of the Spectra ........................................... 9 3 Terms, Definitions and Abbreviations........................................................................ 12 4 The Fraunhofer Lines .................................................................................................... 14 5 Overview and Characteristics of Stellar Spectral Classes ..................................... 15 6 Appearance of Elements and Molecules in the Spectra......................................... 20 7 Spectral Class O ............................................................................................................ 21 8 Wolf Rayet Stars ............................................................................................................ 28 9 Spectral Class B............................................................................................................. 32 10 LBV Stars......................................................................................................................... 39 11 Be Stars ........................................................................................................................... 43 12 Be Shell Stars ................................................................................................................. 46 13 Herbig Ae/Be and T Tauri Protostars ......................................................................... 48 14 Spectral Class A............................................................................................................. 53 15 Spectral Class F ............................................................................................................. 60 16 Spectral Class G ............................................................................................................ 65 17 Spectral Class K............................................................................................................. 70 18 Spectral Class M............................................................................................................ 78 19 Spectral Sequence on the AGB ................................................................................... 81 20 M(e) Stars on the AGB .................................................................................................. 83 21 Spectral Class S on the AGB ....................................................................................... 85 22 Carbon Stars on the AGB ............................................................................................. 91 23 Spectra of Extragalactic Objects ................................................................................ 97 24 Spectra of Emission Nebulae ....................................................................................100 25 Reflexion Spectra of Solar System Bodies..............................................................116 26 Telluric Molecular Absorption ...................................................................................121 27 The Night Sky Spectrum.............................................................................................123 28 Terrestrial Lightsources .............................................................................................125 29 Spectral Classes and – Values of Important Stars ......................................135 30 Required Ionisation Energies for the Individual Elements ...................................138 31 Bright Planetary Nebulae sorted by Excitation Classes........................................139 32 Terminology of the Spectroscopic Wavelenght Domains ....................................140 33 Appendix .......................................................................................................................141 34 Bibliography and Internet ..........................................................................................147 Spectroscopic Atlas for Amateur Astronomers 3 Change log of the atlas versions Version 1.3: Corrections of some labeling-/typing errors and temperature of the O-class stars, some English language corrections. Version 1.4: Corrections of some labeling and typing errors. sect. 1: correction of citation error regarding Spectroweb. Version 1.5: Sect. 7.4, (8) WR133, expansion velocity of the stellar wind, EW value replaced by FWHM value. sect. 8.3 (9.3): chart of the theoretical B-class continuum, correction of the wrongly labeled Ca II line (thanks to Robin Leadbeater!). Version 2.0: New: Sect. 12: Be Shell stars and some adjustments to sect. 11. New: Sect. 18 – 21: Spectral sequence of the Mira Variables on the AGB with the classes M(e), S- and carbon stars C. General revision of the title structure, the table of contents and the sect. 31 “Bibliography and Internet”. Version 3.0: Sect. 3.5: Additional Abbreviations, Sect. 3.7: New: Formula for metallicity. Sect. 7: General revision and expansion to the early O Class. Sec. 10: P Cygni, higher resolved profile sections (900L grating) in the green and blue range of the spectrum. Sect. 13: New: Herbig Ae/Be and T Tauri Protostars Sect. 21: Correction of the wrongly labelled BD Camelopardalis: new HD 22649 Sect. 24: General revision of the section, new: determination of the excitation classes of emission nebulae and table 85: SNR M1/ NGC 1952. Sect. 25: Reflexion spectra: former Tables 85 and 86 ==> new Tables 90 and 91 New: Comet C/2009 P1 Garradd, Table 94 Sect. 27: New: Nigth Sky Spectrum Table 96 Sect. 28: Table 106, Calibration spectrum of the glow starter OSRAM ST 111 Sect. 31: List of bright Planetary Nebulae sorted by excitation classes. All Parameter tables of the individual spectral classes: Correction of the wrong (german) abbreviation “Mrd” by bn (thanks to Dave Dowhos!). Spectroscopic Atlas for Amateur Astronomers 4 Directory of Tables Wavelength Gra- Table Page Topic Objects domain ting 01 16 Overview on the spectral classes Spectral strips of 3950 – 6690 200L various stars 02 17 Overview on the spectral classes Intensity profiles of 3950 – 6690 200L various stars 1 25 Spectral features of the Alnitak ζ Ori 3920 – 6710 200L late O-class Mintaka δ Ori 2 26 Detailed spectrum of a late Alnitak ζ Ori 3950 – 4750 900L O-class star 5740 – 6700 3 27 Spectral features of the early to Θ1 Ori C 3800 – 6700 200L middle O-class 68 Cygni 5 31 Wolf-Rayet WR stars, final stage of WR 133 3850 – 7250 200L the O- and early B-Class WR 140 10 34 Development of spectral features Alnilam ε Ori 3900 – 6700 200L within the B-class Gienah Corvi γ CrV 11 36 Effect of the luminosity on spectra Regulus α Leo 3920 – 4750 900L of the late B-class Rigel β Ori φ Sagittarii 12 38 Detailed spectrum of an early Spica α Vir 3800 – 6750 200L B-class star 3900 – 4750 900L 4800 – 5100 5700 – 6050 6450 – 6600 13 41 LBV star, early B-class P Cygni, 34 Cyg 3900 – 6950 200L P Cygni profiles, 6000 – 6800 900L 13A 42 Detailed spectrum LBV star, early P Cygni 34 Cyg 3850 – 4650 900L B-class, P Cygni profiles 4700 – 6050 14 44 Be- star, early B-class Dschubba δ Sco 3650 – 7000 200L 4820 – 4940 900L 6500 – 6700 6670 – 6690 14A 45 Be-star, early B-Class Tsih γ Cassiopeiae 3970 – 6750 200L 15 47 Be Shell Star, comparison to an ζ Tauri 3800 – 6800 200L “ordinary” Be Star Dschubba δ Sco 17 51 Herbig Ae/Be Proto star R Monocerotis 3900 – 7200 200L NGC 2261 18 52 T Tauri Protostar T Tauri 3900 – 7000 200L 20 55 Development of spectral features Castor α Gem 3900 – 6800 200L within the A-class Altair α Aql 21 56 Detailed spectrum of an early Sirius A α CMa 3900 – 6700 200L A-class star 3900 – 4700 900L 4780 – 5400 22 58 Effects of the luminosity on spectra Vega α Lyr 3900 – 4700 900L of the early A-class Ruchbah δ Cas Deneb α Cyg Spectroscopic Atlas for Amateur Astronomers 5 Wavelength Gra- Table Page Topic Objects domain ting 23 59 Metallicity: Vega vs. Sirius Vega α Lyr 3920 – 4700 900L Sirius A α CMa 30 62 Development of spectral features Adhafera ζ Leo 3830 – 6700 200L within the F-class Procyon α CMi 31 64 Effects of the luminosity on spectra Porrima γ Vir 3920 – 4750 900L of the early F-class Caph β Cas Mirfak α Per 40 67 Development of spectral Muphrid η Boo 3800 – 6600 200L features within the G-class Vindemiatrix ε Vir 41 68 Detailed spectrum of an early G- Sun 3800 – 7200 200L class star 3900 – 4800 900L 42 69 Detailed spectrum of an early G- Sun 4700 – 5700 900L class star 5650 – 6700 50 73 Development of spectral features Arcturus α Boo 3900 – 6800 200L within the K-class Alterf λ Leo 51 74 Detailed spectrum of an early Pollux α Gem 3900 – 6800 200L K-class star 3800 – 4800 900L 52 76 Effects of the luminosity on spectra Alsciaukat α Lyncis 4000 – 4900 900L of the late K-class 61 Cygni B 53 77 Detailed spectrum of a later Aldebaran α Tau 5150 – 5900 900L K-class star 5850 – 6700 60 80 Development of spectral features Antares α Sco 3900 – 7200 200L within the M-class Ras Algethi α Her 63 84 Mira Variable M(e), comparison to Mira o Ceti 3900 – 7200 200L a late classified M-Star Ras Algethi α Her 65 87 Extreme S-Class star, comparison R Cygni 4100 – 7300 200L to a Mira Variable M(e) Mira o Ceti 66 89 Development of spectral features Omikron1 Orionis