COMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 6xxx
|
|
- Sherilyn Gilmore
- 6 years ago
- Views:
Transcription
1 COMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 6xxx Konkoly Observatory Budapest 2 December 2016 HU ISSN CORRELATION OF Hα EMISSION FLUX WITH B & V MAGNITUDES IN THE ECLIPSING BINARY VV Cep POLLMANN, E. 1 ; VOLLMANN, W. 2 ; BENNETT, P.D. 3 1 Emil-Nolde Straße 12, Leverkusen, Germany 2 Dammäckergasse 28/D1/20, A-1210 Wien, Austria 3 Department of Physics & Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada Abstract VV Cephei (= HR 8383 = HD ) is the brightest eclipsing M supergiant binary (M2 Iab + B0-2? V) in the sky, and is a massive binary with one of the longest known orbital periods (7430 days = years) of any eclipsing system. As such, this binary provides a unique opportunity to study the chromosphere, outer atmosphere and stellar wind of a red supergiant star that is spectroscopically similar to the well-studied, bright star Betelgeuse (α Ori). Near eclipse, VV Cep offers a rare chance to observe lines of sight to the hot companion near eclipse that probe deep into the extended outer atmosphere of the M supergiant star. With the next eclipse beginning in August 2017, and lasting nearly two years ( 650 days) from 1st to 4th contact, an extensive observational campaign is planned. In this paper, we report the discovery of a correlation between the visual brightness and the Hα emission flux in VV Cep out of eclipse. Introduction The VV Cep binary is a red supergiant of mass M, with a hot, presumably main-sequence, early B-type companion of comparable mass. The two stars are sufficiently well separated that Roche lobe mass transfer does not occur at present, and given the high orbital eccentricity (e = 0.346, Wright 1977), probably has not occurred over the evolutionary history of the system. (Orbits of binaries undergoing Roche lobe mass transfer circularize on short timescales). In the ultraviolet (UV), the hot companion appears embedded in a region of circumstellar gas, as inferred from the persistent veiling that obscures the UV photospheric spectrum of the B-star companion. The gas around the companion is probably a result of wind accretion from the massive wind of the M supergiant. In VV Cep, Hα emission is especially prominent, with peak fluxes of times that of the (M star) continuum. This Hα emission exhibits radial velocity behaviour opposite to that of the M supergiant, implying a source near the hot companion (Wright 1977). Even though this emission declines sharply for higher Balmer lines, at times Balmer emission remains visible from levels up to n 16. Balmer continuum emission is often observed at wavelengths shortward of 3700 Å, and sometimes dominates this part of the UV spectrum (Bennett & Bauer 2015). In the UV, lines of Fe II also appear strongly in emission, and are probably pumped by Lyman-α and Lyman-β emission (Bennett & Bauer 2015). The great width of these Fe II emission lines (with wings out to 300 km s 1 ) suggests the lineforming region is in Keplerian rotation around the B star companion, as these velocities are far larger than any other observed in the circumstellar environment of VV Cep. Although the source of the companion s emission spectrum is usually attributed to accretion of circumstellar gas from the M star onto the hot star, it is likely that the emission luminosity comes not from the release of gravitational energy, but from recombination of circumstellar hydrogen photoionized by the B star s Lyman continuum. The Hα emission is variable on both short timescales of 150 days and longer timescales of several years. The slow variability in Hα flux appears to correlate with the orbital separation of the two stars, being larger when the companion is near periastron (Bennett, private communication). However, the cause of the fast, short-term variability was unknown until now.
2 Observations and Results VV Cep is a 5th magnitude system of variable visual brightness, with V magnitudes ranging from Due to its high declination (+64 ), VV Cep is circumpolar and well-suited for year-round observations at northern mid-latitude sites. In preparation for the VV Cep international campaign, contemporaneous observations of B and V band DSLR photometry and Hα emission equivalent width (EW) have been obtained over the past three years. A time series of V photometry from W. Vollmann is shown in Figure 1, and Hα EWs from the ARAS spectroscopy group ( are presented in Figure 2. Figure 1. DSLR V magnitude of VV Cep, observed by W. Vollmann Figure 2. Hα EW of VV Cep, observed by the ARAS Spectroscopy group 2
3 Figure 3 shows the correlation between the Hα emission EW and contemporaneous V photometry of VV Cep for the period January 2014 to October 2016 (JD { ) obtained by W. Vollmann (DSLR, AAVSO & BAV-Germany), B. Hassforther (DSLR, BAV-Germany) and G. Samolyk (CCD, AAVSO data base). We nd the Hα EW is correlated with V magnitude, with a correlation coefficient of R = 0.84 over this period. Although this relationship is reminiscent of the well-known relationship between stellar brightness and Be star emission fluxes (e.g., Harmanec 1983), the cause must be different for VV Cep because most of the visible continuum flux comes from the M supergiant (V 5.0), and not the 7th magnitude B-type companion responsible for the Hα emission. Note that the V band data also includes contributions from the bright Hα emission fluxes, which somewhat complicates interpretation of the results. One way of confrming the correlation of the Figure 3 result is to obtain simultaneous photometry in other bands, e.g., B band. B photometry has the additional advantage that contamination from the weaker Hγ and Hβ Balmer emission lines is much less than from Hα, which contributes significantly to the integrated V-band light of VV Cep. Figure 4 shows a preliminary period analysis of the V photometry of Figure 1, demonstrating that the period of the brightness change lies close to the 150-day period first proposed by Hayasaka et al. (1971). However, many other periods have been reported in the literature over the years: e.g., periods of 60, 110, 114, 116, and 280 days (Graczyk et al. 1999; Saito et al. 1980; McCook et al. 1978; Baldinelli et al. 1979; Pfeiffer et al. 1989). This behaviour suggests the short-term variability is somewhat irregular in nature, and probably has a substantial stochastic component. Indeed, the plot of the V variability, phased to a period days (Figure 4), shows a substantial fraction of this variability remains unexplained by this periodic oscillation. Figure 3. Correlation of VV Cep Hα EW with V magnitude 3
4 Figure 4. Period analysis of the data in Fig. 1; Period = ± 1.2 days W. Vollmann and G. Samolyk also derived B photometry, concurrent with the DSLR V observations (Figure 5). However because of the lower DSLR pixel sensitivity of Vollmann's B photometry, these data are not as precise, nor as accurate, as the V photometry. Vollmann used the Johnson B brightness of the reference stars, but did not transform to the Johnson B system, and therefore there is an offset in the derived B magnitudes compared to Samolyk's more accurate Johnson B magnitudes. Nevertheless, a similar inverse correlation is also seen between the B magnitudes and Hα EW. The addition of this B photometry confirms the inverse nature of the correlation between the Hα emission fluxes and M star brightness shown in Figure 3, derived from a large number of independent DSLR, CCD, and spectroscopic observations by a large number of individual observers over a period of several years. Figure 5. Hα EW vs. DSLR blue (B)-Band Photometry of VV Cep 4
5 Conclusions The observations presented here span the period from JD to JD , corresponding to orbital phases , measured from zero phase at mid-eclipse. The amplitude of the photometric variability is ΔV mag, whereas the amplitude of the total eclipse of the B star is only is ΔV 0.15 mag. The M supergiant is about 2 magnitudes brighter at V than the hot companion. Therefore, changes in disk size and brightness of the B-type companion similar to those observed in Be stars could only result in very limited photometric variability, and so cannot be the cause of the observed V-band photometric variability in VV Cep. Instead, the observed photometric variability must be intrinsic to the M supergiant. The period and photometric amplitude of the variability is quite similar to that resulting from irregular pulsation in other, single late-type supergiants. All of this strongly suggests that the photometric variability observed for VV Cep is intrinsic, and due to irregular pulsation of the M star. In that case, the variable Hα emission flux must be a consequence of the M supergiant's pulsation. One possibility is that the local wind density near the hot companion varies with the change in M star radius over the pulsational cycle, resulting in a higher ambient gas density near the hot star when the M star is at maximum radial extent. This higher circumstellar density results in a more efficient conversion of B-star Lyman continuum photons into Balmer line emission. At maximum radius, the effective temperature of the M star is near minimum, with redder B and V colours, and fainter B and V magnitudes, consistent with the observed Hα-V relation. The cause of the variable emission from the B star companion of VV Cep, and especially the very prominent Hα emission, has remained a mystery for many years. In this paper, we present the first quantitative connection between the variability of the companion's emission flux and the photometric variability of the M supergiant. Furthermore, since the only obvious physical link between these physically separated sources (the VV Cep B and M stars) is the M star wind, we propose that it is the indirect effect of M supergiant pulsation on the wind properties that is responsible for the variability of the Hα (and other Balmer line) emission flux. Therefore, if confirmed by further observation, the prominent Hα emission in VV Cep (and similar stars such as KQ Pup) may provide a useful diagnostic tool for monitoring the behaviour of the supergiant winds in these binaries. Acknowledgements We are grateful to Sara and Carl Sawicki (Alpine, Texas, USA) for their helpful improvements and suggestions in language. We are grateful to the other observers of the ARAS spectroscopy group: J. N. Terry, B. Koch, O. Thizy, E. Betrand, O. Garde, F. Teyssier, T. Lester, J. Foster, Ch. Buil, M. Schwarz, J. Montier, J. J. Boussat, Dong Li, J. Guarro, & D. Hyde, for their contribution of spectra of VV Cep used to determine for the H EW. We wish to thank Bela Hassforther (Deutsche Arbeitsgemeinschaft Veränderliche Sterne, BAV-Germany) for supplying additional V photometry. Finally, we acknowledge, with thanks, the use of variable star observations contributed to the AAVSO International Database by Gerard Samolyk. 5
6 References: Baldinelli, L., Ghedini, S., Marmi, S. 1979, IBVS, 1675 Bennett, P.D., Bauer, W.H. 2015, in Giants of Eclipse: The Zeta Aurigae Stars and Other Binary Systems, Astrophysics and Space Science Library, Vol. 408, ed. T.B. Ake, & E. Griffin, (Heidelberg: Springer), 85 Graczyk, D., Mikolajewski, M., Janowski, J. L. 1999, IBVS, 4679 Harmanec, P., 1983, Hvar Obs. Bull., 7, 55 Hayasaka, T., Saijo, K., Sato, H., Saito, M., Kitamura, M. 1977, Tokyo Astr. Bull. Second Series, 247, 2865 Hutchings, J. B., Wright, K. O. 1971, MNRAS, 155, 203 McCook, G., P., Guinan, E., F. 1978, IBVS, 1385 Pfeiffer, R. J., Maffei, J. C. 1989, BAAS, 21, 792 Saito, M., Sato, H., Saijo, K., Hayasaka, T. 1980, PASJ 32, Wright, K. O. 1977, JRASC, 71, 152 6
VV Cephei Eclipse Campaign 2017/19
VV Cephei Eclipse Campaign 2017/19 Jeffrey L. Hopkins (187283) Hopkins Phoenix Observatory 7812 West Clayton Drive, Phoenix, Arizona USA phxjeff@hposoft.com Philip D. Bennett Department of Astronomy &
More informationThe Binary System VV Cephei Eclipse Campaign 2017/2019 OHP-Meeting July 2017
The Binary System VV Cephei Eclipse Campaign 2017/2019 OHP-Meeting July 2017 Ernst Pollmann International Working Group Active Spectroscopy in Astronomy http://astrospectroscopy.de 3 One of the best known
More informationSAS The Symposium on Telescope Science. Proceedings for the 34th Annual Conference of the Society for Astronomical Sciences
Proceedings for the 34th Annual Conference of the Society for Astronomical Sciences SAS-2015 The Symposium on Telescope Science Editors: Robert K. Buchheim Jerry L. Foote Dale Mais June 11-13, 2015 Ontario,
More informationIntermediate Report December 2012 Campaign: Photometry and Spectroscopy of P Cyg
Intermediate Report December 2012 Campaign: Photometry and Spectroscopy of P Cyg Ernst Pollmann Emil-Nolde-Str. 12, 51375 Leverkusen, Germany; ernst-pollmann@t-online.de Wolfgang Vollmann Dammäckergasse
More informationPhotometric and spectroscopic observations of the 2014 eclipse of the complex binary EE Cephei
Photometric and spectroscopic observations of the 2014 eclipse of the complex binary EE Cephei David Boyd Variable Star Section, British Astronomical Association, [davidboyd@orion.me.uk] Abstract We report
More informationCOMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 6109
COMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 6109 Konkoly Observatory Budapest 5 June 2014 HU ISSN 0374 0676 LONG-TERM MONITORING OF Hα EMISSION STRENGTH AND PHOTOMETRIC
More informationMass transfer in Binary-System VV Cep
Mass transfer in Binary-System VV Cep Fig: 1 Two of the best known and largest stars in space, which can be found hidden and close together within a dark interstellar cloud of dust in the constellation
More informationPhotometric and spectroscopic observations of the outburst of the symbiotic star AG Draconis between March and June 2016
Photometric and spectroscopic observations of the outburst of the symbiotic star AG Draconis between March and June 2016 David Boyd Variable Star Section, British Astronomical Association, [davidboyd@orion.me.uk]
More informationDetermining the magnitudes and spectral types of the components of the binary Mira X Ophiuchi
Determining the magnitudes and spectral types of the components of the binary Mira X Ophiuchi David Boyd Variable Star Section, British Astronomical Association, [davidboyd@orion.me.uk] Abstract Several
More informationarxiv:astro-ph/ v1 23 Oct 2002
Evolution of the symbiotic nova RX Puppis J. Mikołajewska, E. Brandi, L. Garcia, O. Ferrer, C. Quiroga and G.C. Anupama arxiv:astro-ph/0210505v1 23 Oct 2002 N. Copernicus Astronomical Center, Bartycka
More informationObservingwith a LISA spectrograph. David Boyd BAAVSS, AAVSO, CBA
Observingwith a LISA spectrograph David Boyd BAAVSS, AAVSO, CBA For me, the appeal of spectroscopy is in its scientific potential Photometry reveals changes in a star s brightness R Scutum Spectroscopy
More informationarxiv:astro-ph/ v1 22 Nov 2000
**TITLE** ASP Conference Series, Vol. **VOLUME**, **PUBLICATION YEAR** **EDITORS** OAO1657 415 : A Missing Link in High Mass X-ray Binaries? arxiv:astro-ph/0011401v1 22 Nov 2000 D.H. Maxwell, A.J. Norton
More informationAG Draconis. A high density plasma laboratory. Dr Peter Young Collaborators A.K. Dupree S.J. Kenyon B. Espey T.B.
AG Draconis A high density plasma laboratory Collaborators A.K. Dupree S.J. Kenyon B. Espey T.B. Ake p.r.young@rl.ac.uk Overview CHIANTI database Symbiotic Stars AG Draconis FUSE FUSE observations of AG
More informationSPECTROGRAPHIC OBSERVATIONS OF VV CEPHEI DURING INGRESS AND TOTALITY, *
SPECTROGRAPHIC OBSERVATIONS OF VV CEPHEI DURING INGRESS AND TOTALITY, 1956-57* A. McKellar, K. O. Wright, and J. D. Francis Dominion Astrophysical Observatory Victoria, B.C. In a previous paper, 1 a description
More informationThe Periastron Passages of 28 Tau (published at IBVS No. 6199)
The Periastron Passages of 28 Tau 2012-2015 (published at IBVS No. 6199) Within the time span January 2012 to February 2015 a group of 24 observers of the ARAS community (http://www.astrosurf.com/aras/)
More informationAstr 5465 Feb. 6, 2018 Today s Topics
Astr 5465 Feb. 6, 2018 Today s Topics Stars: Binary Stars Determination of Stellar Properties via Binary Stars Classification of Binary Stars Visual Binaries Both stars visible Only one star visible Spectroscopic
More informationAstronomy 110 Homework #07 Assigned: 03/06/2007 Due: 03/13/2007. Name: (Answer Key)
Astronomy 110 Homework #07 Assigned: 03/06/2007 Due: 03/13/2007 Name: (Answer Key) Directions: Listed below are twenty (20) multiple-choice questions based on the material covered by the lectures thus
More informationAstronomy 421. Lecture 8: Binary stars
Astronomy 421 Lecture 8: Binary stars 1 Key concepts: Binary types How to use binaries to determine stellar parameters The mass-luminosity relation 2 Binary stars So far, we ve looked at the basic physics
More informationLines of Hydrogen. Most prominent lines in many astronomical objects: Balmer lines of hydrogen
The Family of Stars Lines of Hydrogen Most prominent lines in many astronomical objects: Balmer lines of hydrogen The Balmer Thermometer Balmer line strength is sensitive to temperature: Most hydrogen
More informationAstronomy 113. Dr. Joseph E. Pesce, Ph.D. Dr. Joseph E. Pesce, Ph.D.
Astronomy 113 Dr. Joseph E. Pesce, Ph.D. The Nature of Stars 8-2 Parallax For nearby stars - measure distances with parallax July 1 AU d p A A A January ³ d = 1/p (arcsec) [pc] ³ 1pc when p=1arcsec; 1pc=206,265AU=3
More informationAstr 2320 Tues. March 7, 2017 Today s Topics
Astr 2320 Tues. March 7, 2017 Today s Topics Chapter 13: Stars: Binary Stars Determination of Stellar Properties vi Binary Stars Classification of Binary Stars Visual Binaries Both stars visible Only one
More informationDr. Reed L. Riddle. Close binaries, stellar interactions and novae. Guest lecture Astronomy 20 November 2, 2004
Dr. Reed L. Riddle Close binaries, stellar interactions and novae Guest lecture Astronomy 20 November 2, 2004 Gravitational Tides Look at the forces acting on one body orbiting another - more pull on closer
More informationASTR-1020: Astronomy II Course Lecture Notes Section III
ASTR-1020: Astronomy II Course Lecture Notes Section III Dr. Donald G. Luttermoser East Tennessee State University Edition 4.0 Abstract These class notes are designed for use of the instructor and students
More informationChapter 8: The Family of Stars
Chapter 8: The Family of Stars Motivation We already know how to determine a star s surface temperature chemical composition surface density In this chapter, we will learn how we can determine its distance
More informationChapter 10 Measuring the Stars
Chapter 10 Measuring the Stars Some of the topics included in this chapter Stellar parallax Distance to the stars Stellar motion Luminosity and apparent brightness of stars The magnitude scale Stellar
More informationPhotometric Observation and Light Curve Analysis of Binary System ER-Orionis
J. Astrophys. Astr. (2010) 31, 97 104 Photometric Observation and Light Curve Analysis of Binary System ER-Orionis M. M. Lame e 1,, B. Javanmardi 2, & N. Riazi 2, 1 Leiden Observatory, Leiden University,
More informationECLIPSING AND SPECTROSCOPIC BINARY STARS
FINAL YEAR SEMINAR, OLD PROGRAM ECLIPSING AND SPECTROSCOPIC BINARY STARS Author: Franci Gorjup Mentor: Prof. dr. Tomaž Zwitter Ljubljana, December 2013 Abstract: First, we will see, what kind of binary
More informationASTR Look over Chapter 15. Good things to Know. Triangulation
ASTR 1020 Look over Chapter 15 Good things to Know Triangulation Parallax Parsecs Absolute Visual Magnitude Distance Modulus Luminosity Balmer Lines Spectral Classes Hertzsprung-Russell (HR) diagram Main
More informationYoung stellar objects and their environment
Recent Advances in Star Formation: Observations and Theory ASI Conference Series, 2012, Vol. 4, pp 107 111 Edited by Annapurni Subramaniam & Sumedh Anathpindika Young stellar objects and their environment
More informationThe variable nature of the OB star HD13831 Dr. Amira Val Baker. Celebrating Ten Years of Science with STELLA Wednesday 9th November 2016
The variable nature of the OB star HD13831 Dr. Amira Val Baker Celebrating Ten Years of Science with STELLA Wednesday 9th November 2016 STELLA robotic telescope Dr Ana Gonzales-Galan Celebrating Ten Years
More informationOGLE-TR-56. Guillermo Torres, Maciej Konacki, Dimitar D. Sasselov and Saurabh Jha INTRODUCTION
OGLE-TR-56 Guillermo Torres, Maciej Konacki, Dimitar D. Sasselov and Saurabh Jha Harvard-Smithsonian Center for Astrophysics Caltech, Department of Geological and Planetary Sciences University of California
More informationMeasuring the Stars. The measurement of distances The family of distance-measurement techniques used by astronomers to chart the universe is called
Measuring the Stars How to measure: Distance Stellar motion Luminosity Temperature Size Evolutionary stage (H-R diagram) Cosmic distances Mass The measurement of distances The family of distance-measurement
More informationInfrared Spectroscopy of the Black Hole Candidate GRO J
Infrared Spectroscopy of the Black Hole Candidate GRO J1655-40 1 Francis T. O Donovan March 19th, 2004 1 Based on a paper by F. T. O Donovan & P. J. Callanan (in preparation). Black Holes in the Sky At
More informationActuality of Exoplanets Search. François Bouchy OHP - IAP
Actuality of Exoplanets Search François Bouchy OHP - IAP How detect extrasolar planets? Two main difficulties : 1 A tiny angular separation 0.75 arcsec Sun Jupiter at 4 light years 4 Sun Jupiter at 100
More informationBasics, types Evolution. Novae. Spectra (days after eruption) Nova shells (months to years after eruption) Abundances
Basics, types Evolution Novae Spectra (days after eruption) Nova shells (months to years after eruption) Abundances 1 Cataclysmic Variables (CVs) M.S. dwarf or subgiant overflows Roche lobe and transfers
More informationBinary Stars (continued) ASTR 2120 Sarazin. γ Caeli - Binary Star System
Binary Stars (continued) ASTR 2120 Sarazin γ Caeli - Binary Star System Visual Binaries: Types of Binary Stars Spectroscopic Binaries: Eclipsing Binaries: Periodic changes in brightness, stars block one
More informationTidal effects and periastron events in binary stars
Tidal effects and periastron events in binary stars Gloria Koenigsberger & Edmundo Moreno Universidad Nacional Autónoma de México gloria@fis.unam.mx; edmundo@astroscu.unam.mx December 8, 2008 ABSTRACT
More informationFUSE Observations of a Mira Variable Star
Proceedings of 12th Cambridge Workshop on Cool Stars, Stellar Systems, & The Sun, 2003 University of Colorado. FUSE Observations of a Mira Variable Star Donald G. Luttermoser 1, Michael W. Castelaz 2 Abstract.
More informationHOMEWORK - Chapter 17 The Stars
Astronomy 20 HOMEWORK - Chapter 7 The Stars Use a calculator whenever necessary. For full credit, always show your work and explain how you got your answer in full, complete sentences on a separate sheet
More informationGuiding Questions. Measuring Stars
Measuring Stars Guiding Questions 1. How far away are the stars? 2. What is meant by a first-magnitude or second magnitude star? 3. Why are some stars red and others blue? 4. What are the stars made of?
More informationUniversitetski prospect 13, Moscow, , Russia; 2 Faculty of Physics, M. V. Lomonosov Moscow State University,
Baltic Astronomy, vol. 25, 317 323, 2016 DETAILS OF THE CLASSIFICATION OF SYMBIOTIC STARS: THE CASE OF THE SYMBIOTIC NOVA AG PEG A. A. Tatarnikova 1, M. A. Burlak 1, D. V. Popolitova 2, T. N. Tarasova
More informationSpectropolarimetry of Beta Lyrae: Constraining the Location of the Hot Spot and Jets
Spectropolarimetry of Beta Lyrae: Constraining the Location of the Hot Spot and Jets Jamie R. Lomax 1 and Jennifer L. Hoffman 1 arxiv:1011.3548v1 [astro-ph.sr] 15 Nov 2010 1 University of Denver, Denver,
More informationarxiv: v1 [astro-ph.sr] 26 Mar 2013
arxiv:1303.6401v1 [astro-ph.sr] 26 Mar 2013 ISSN 1845 8319 A NEW LOOK INTO THE SPECTRAL AND LIGHT VARIATIONS OF ε AUR P. HARMANEC 1, H. BOŽIĆ 2, D. KORČÁKOVÁ 1, L. KOTKOVÁ 3, P. ŠKODA 3, M. ŠLECHTA 3,
More informationBased on papers presented at the 88th and 89th AAVSO Spring meetings; revised Spring 2001
Schmude et al., JAAVSO Volume 30, 2001 53 PHOTOMETRIC STUDY OF RX CEPHEI Richard W. Schmude, Jr. Joy Jones Benjamin Jimenez Gordon College 419 College Dr. Barnesville, GA 30204 Based on papers presented
More informationThe Ultraviolet Spectrum of VV Cephei Out of Eclipse
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC, 112:31È49, 2000 January ( 2000. The Astronomical Society of the PaciÐc. All rights reserved. Printed in U.S.A. The Ultraviolet Spectrum of VV Cephei
More informationPhysics Homework Set I Su2015
1) The particles which enter into chemical reactions are the atom's: 1) _ A) protons. B) positrons. C) mesons. D) electrons. E) neutrons. 2) Which of the following type of electromagnetic radiation has
More information125-Day Spectral Record of the Bright Nova Delphini 2013 (V339 Del)
Mooers and Wiethoff, JAAVSO Volume 42, 2014 161 125-Day Spectral Record of the Bright Nova Delphini 2013 (V339 Del) Howard D. Mooers Department of Geological Sciences, University of Minnesota Duluth, Duluth,
More informationSearching for Other Worlds
Searching for Other Worlds Lecture 32 1 In-Class Question What is the Greenhouse effect? a) Optical light from the Sun is reflected into space while infrared light passes through the atmosphere and heats
More informationThe 2003 eclipse of EE Cep is coming. A review of past eclipses
A&A 403, 1089 1094 (2003) DOI: 10.1051/0004-6361:20030430 c ESO 2003 Astronomy & Astrophysics The 2003 eclipse of EE Cep is coming A review of past eclipses D. Graczyk 1, M. Mikołajewski 1,T.Tomov 1,D.Kolev
More informationAstronomy 421. Lecture 14: Stellar Atmospheres III
Astronomy 421 Lecture 14: Stellar Atmospheres III 1 Lecture 14 - Key concepts: Spectral line widths and shapes Curve of growth 2 There exists a stronger jump, the Lyman limit, occurring at the wavelength
More information7. BINARY STARS (ZG: 12; CO: 7, 17)
7. BINARY STARS (ZG: 12; CO: 7, 17) most stars are members of binary systems or multiple systems (triples, quadruples, quintuplets,...) orbital period distribution: P orb = 11 min to 10 6 yr the majority
More information3.4 Transiting planets
64 CHAPTER 3. TRANSITS OF PLANETS: MEAN DENSITIES 3.4 Transiting planets A transits of a planet in front of its parent star occurs if the line of sight is very close to the orbital plane. The transit probability
More informationThe Wolf-Rayet + O binary WR 140 in Cygnus
The Wolf-Rayet + O binary WR 140 in Cygnus http://spektroskopie.fg-vds.de Fachgruppe SPEKTROSKOPIE 1. The system The archetype of colliding-wind binary (CWB) systems is the 7.9-year period WR+O binary
More informationExamination paper for FY2450 Astrophysics
1 Department of Physics Examination paper for FY2450 Astrophysics Academic contact during examination: Robert Hibbins Phone: 94 82 08 34 Examination date: 04-06-2013 Examination time: 09:00 13:00 Permitted
More informationDistribution of X-ray binary stars in the Galaxy (RXTE) High-Energy Astrophysics Lecture 8: Accretion and jets in binary stars
High-Energy Astrophysics Lecture 8: Accretion and jets in binary stars Distribution of X-ray binary stars in the Galaxy (RXTE) Robert Laing Primary Compact accreting binary systems Compact star WD NS BH
More informationIndirect Methods: gravitational perturbation of the stellar motion. Exoplanets Doppler method
Indirect Methods: gravitational perturbation of the stellar motion Exoplanets The reflex motion of the star is proportional to M p /M * This introduces an observational bias that favours the detection
More informationThe cosmic distance scale
The cosmic distance scale Distance information is often crucial to understand the physics of astrophysical objects. This requires knowing the basic properties of such an object, like its size, its environment,
More informationPhysics Homework Set 2 Sp 2015
1) A large gas cloud in the interstellar medium that contains several type O and B stars would appear to us as 1) A) a reflection nebula. B) a dark patch against a bright background. C) a dark nebula.
More informationBlack Hole and Host Galaxy Mass Estimates
Black Holes Black Hole and Host Galaxy Mass Estimates 1. Constraining the mass of a BH in a spectroscopic binary. 2. Constraining the mass of a supermassive BH from reverberation mapping and emission line
More information6. Detached eclipsing binaries
Rolf Kudritzki SS 2015 6. Detached eclipsing binaries 50% of all stars live in binary systems and some of them are eclipsing 1 Rolf Kudritzki SS 2015 classification of binary systems by geometry of equipotential
More informationEvidence of coupling between the thermal and nonthermal emission in the gamma-ray binary LS I through optical observations
Evidence of coupling between the thermal and nonthermal emission in the gamma-ray binary LS I +61 303 through optical observations X. Paredes-Fortuny, M. Ribo, V. Bosch-Ramon, J. Casares, O. Fors, J. Nu
More informationFormation and Evolution of Planetary Systems
Formation and Evolution of Planetary Systems Meyer, Hillenbrand et al., Formation and Evolution of Planetary Systems (FEPS): First Results from a Spitzer Legacy Science Program ApJ S 154: 422 427 (2004).
More informationBUILDING GALAXIES. Question 1: When and where did the stars form?
BUILDING GALAXIES The unprecedented accuracy of recent observations of the power spectrum of the cosmic microwave background leaves little doubt that the universe formed in a hot big bang, later cooling
More informationNAME: VARIABLE STARS. What will you learn in this Lab?
NAME: VARIABLE STARS What will you learn in this Lab? This lab will cover three of the main types of variable stars that we observe in our night sky: RR Lyrae stars, Cepheid variable stars and Eclipsing
More informationTypes of Stars 1/31/14 O B A F G K M. 8-6 Luminosity. 8-7 Stellar Temperatures
Astronomy 113 Dr. Joseph E. Pesce, Ph.D. The Nature of Stars For nearby stars - measure distances with parallax 1 AU d p 8-2 Parallax A January ³ d = 1/p (arcsec) [pc] ³ 1pc when p=1arcsec; 1pc=206,265AU=3
More informationASTRONOMY AND ASTROPHYSICS. High resolution spectroscopy of symbiotic stars. V. Orbital and stellar parameters for FG Ser (AS 296)
Astron. Astrophys. 353, 952 957 (2000) High resolution spectroscopy of symbiotic stars V. Orbital and stellar parameters for FG Ser (AS 296) ASTRONOMY AND ASTROPHYSICS U. Mürset 1, T. Dumm 1, S. Isenegger
More informationTrES Exoplanets and False Positives: Finding the Needle in the Haystack
Transiting Extrasolar Planets Workshop ASP Conference Series, Vol. 366, 2007 C. Afonso, D. Weldrake and Th. Henning TrES Exoplanets and False Positives: Finding the Needle in the Haystack F. T. O Donovan
More informationStars - spectral types
Stars - spectral types 1901: Led by Annie Jump Cannon, Harvard astronomers looked at the spectra of >200,000 stars. Classified them as A, B, C etc. Cannon rearranged them into OBAFGKM based on how lines
More informationLecture 12: Distances to stars. Astronomy 111
Lecture 12: Distances to stars Astronomy 111 Why are distances important? Distances are necessary for estimating: Total energy released by an object (Luminosity) Masses of objects from orbital motions
More informationPayne-Scott workshop on Hyper Compact HII regions Sydney, September 8, 2010
Payne-Scott workshop on Hyper Compact HII regions Sydney, September 8, 2010 Aim Review the characteristics of regions of ionized gas within young massive star forming regions. Will focus the discussion
More informationThe Hertzprung-Russell Diagram. The Hertzprung-Russell Diagram. Question
Key Concepts: Lecture 21: Measuring the properties of stars (cont.) The Hertzsprung-Russell (HR) Diagram (L versus T) The Hertzprung-Russell Diagram The Stefan-Boltzmann Law: flux emitted by a black body
More informationClassification of nova spectra
International Workshop on Stellar Spectral Libraries ASI Conference Series, 2012, Vol. 6, pp 143 149 Edited by Ph. Prugniel & H. P. Singh Classification of nova spectra G. C. Anupama Indian Institute of
More informationAST-1002 Section 0459 Review for Final Exam Please do not forget about doing the evaluation!
AST-1002 Section 0459 Review for Final Exam Please do not forget about doing the evaluation! Bring pencil #2 with eraser No use of calculator or any electronic device during the exam We provide the scantrons
More informationMeasuring Radial & Tangential Velocity. Radial velocity measurement. Tangential velocity measurement. Measure the star s Doppler shift
17. The Nature of the Stars Parallax reveals stellar distance Stellar distance reveals luminosity Luminosity reveals total energy production The stellar magnitude scale Surface temperature determines stellar
More informationMeasuring Radial & Tangential Velocity. Radial velocity measurement. Tangential velocity measurement. Measure the star s Doppler shift
17. The Nature of the Stars Parallax reveals stellar distance Stellar distance reveals luminosity Luminosity reveals total energy production The stellar magnitude scale Surface temperature determines stellar
More informationVariable Stars South. Who we are What we do. 2
Who we are What we do www.variablestarssouth.org 2 We are a group of amateur astronomers. Mainly from Australia New Zealand with a few from other parts of the globe We study stars that vary in brightness
More informationElectromagnetic Spectra. AST443, Lecture 13 Stanimir Metchev
Electromagnetic Spectra AST443, Lecture 13 Stanimir Metchev Administrative Homework 2: problem 5.4 extension: until Mon, Nov 2 Reading: Bradt, chapter 11 Howell, chapter 6 Tenagra data: see bottom of Assignments
More informationThe orbital period variations of AH Virgins
Research in Astron. Astrophys. Vol.0 (20xx) No.0, 000 000 http://www.raa-journal.org http://www.iop.org/journals/raa Research in Astronomy and Astrophysics The orbital period variations of AH Virgins Ming
More informationLecture 21. Stellar Size
Lecture 21 Stellar Mass; The Main Sequence Visual and Spectroscopic Binaries Mass and the Main Sequence Explaining the Main Sequence Mar 8, 2006 Astro 100 Lecture 21 1 Stellar Size Taking ratios to the
More informationScience Olympiad Astronomy C Division Event National Exam
Science Olympiad Astronomy C Division Event National Exam University of Nebraska-Lincoln May 15-16, 2015 Team Number: Team Name: Instructions: 1) Please turn in all materials at the end of the event. 2)
More informationThe Deaths of Stars. The Southern Crab Nebula (He2-104), a planetary nebula (left), and the Crab Nebula (M1; right), a supernova remnant.
The Deaths of Stars The Southern Crab Nebula (He2-104), a planetary nebula (left), and the Crab Nebula (M1; right), a supernova remnant. Once the giant phase of a mediummass star ends, it exhales its outer
More informationX-ray and infrared properties of Be/X-ray binary pulsars
Recent Trends in the Study of Compact Objects: Theory and Observation ASI Conference Series, 203, Vol. 8, pp 03 08 Edited by Santabrata Das, Anuj Nandi and Indranil Chattopadhyay X-ray and infrared properties
More informationAstronomy 7A Midterm #1 September 29, 2016
Astronomy 7A Midterm #1 September 29, 2016 Name: Section: There are 2 problems and 11 subproblems. Write your answers on these sheets showing all of your work. It is better to show some work without an
More informationStellar Masses: Binary Stars
Stellar Masses: Binary Stars The HR Diagram Again A Diagram for People Q: What is happening here? A: People grow. They are born small, and then grow in height and mass as they age (with a fair bit of individual
More informationNational Science Olympiad Astronomy C Division Event 19 May 2012 University of Central Florida Orlando, FL
National Science Olympiad Astronomy C Division Event 19 May 2012 University of Central Florida Orlando, FL Artist Illustration of Red Giant, White Dwarf and Accretion Disk (Wikimedia) TEAM NUMBER: TEAM
More informationThe orbital period variations of AH Virginis
RAA 2015 Vol. 15 No. 2, 275 280 doi: 10.1088/1674 4527/15/2/010 http://www.raa-journal.org http://www.iop.org/journals/raa Research in Astronomy and Astrophysics The orbital period variations of AH Virginis
More informationMeasuring star formation in galaxies and its evolution. Andrew Hopkins Australian Astronomical Observatory
Measuring star formation in galaxies and its evolution Andrew Hopkins Australian Astronomical Observatory Evolution of Star Formation Evolution of Star Formation Evolution of Star Formation Evolution of
More informationRevision: Sun, Stars (and Planets) See web slides of Dr Clements for Planets revision. Juliet Pickering Office: Huxley 706
Revision: Sun, Stars (and Planets) See web slides of Dr Clements for Planets revision Juliet Pickering Office: Huxley 706 Office hour (Pickering): Thursday 22nd May 12-11 pm Outline overview of first part
More informationMeasuring the components of the binary Mira X Ophiuchi. David Boyd
Measuring the components of the binary Mira X Ophiuchi David Boyd X Ophwas Variable Star of the Year in the 2014 BAA Handbook The article included this light curve from observations by John Toone It appears
More informationStar formation : circumstellar environment around Young Stellar Objects
Bull. Astr. Soc. India (2005) 33, 327 331 Star formation : circumstellar environment around Young Stellar Objects Manoj Puravankara Inter-University Centre for Astronomy and Astrophysics, Pune - 411007,
More informationBinary Nature and Long-Term Variations of g Cassiopeiae
Publications of the Astronomical Society of the Pacific, 114:1226 1233, 2002 November 2002. The Astronomical Society of the Pacific. All rights reserved. Printed in U.S.A. Binary Nature and Long-Term Variations
More information1 of 6 5/2/2015 6:12 PM
1 of 6 5/2/2015 6:12 PM 1. What is parallax? The distance to an object, measured in parsecs. The difference between the apparent and absolute magnitude. The apparent shift in POSITION of an object caused
More informationObservations of Pulsating Stars
Observations of Pulsating Stars Noel Richardson April 15, 2008 1 Introduction Pulsating stars are stars that show some sort of instability, often which can be called vibration or oscillation just as easily
More informationThe Family of Stars. Chapter 13. Triangulation. Trigonometric Parallax. Calculating Distance Using Parallax. Calculating Distance Using Parallax
The Family of Stars Chapter 13 Measuring the Properties of Stars 1 Those tiny glints of light in the night sky are in reality huge, dazzling balls of gas, many of which are vastly larger and brighter than
More informationShort-period cataclysmic variables at Observatorio Astronomico Nacional IA UNAM.
Contrib. Astron. Obs. Skalnaté Pleso 43, 294 299, (214) Short-period cataclysmic variables at Observatorio Astronomico Nacional IA UNAM. S. Zharikov Observatorio Astronomico Nacional, Instituto de Astronomia,
More informationChapter 15 Lecture. The Cosmic Perspective Seventh Edition. Surveying the Stars Pearson Education, Inc.
Chapter 15 Lecture The Cosmic Perspective Seventh Edition Surveying the Stars 15.1 Properties of Stars Our goals for learning: How do we measure stellar luminosities? How do we measure stellar temperatures?
More informationHD Transits HST/STIS First Transiting Exo-Planet. Exoplanet Discovery Methods. Paper Due Tue, Feb 23. (4) Transits. Transits.
Paper Due Tue, Feb 23 Exoplanet Discovery Methods (1) Direct imaging (2) Astrometry position (3) Radial velocity velocity Seager & Mallen-Ornelas 2003 ApJ 585, 1038. "A Unique Solution of Planet and Star
More informationSun. Sirius. Tuesday, February 21, 2012
Spectral Classification of Stars Sun Sirius Stellar Classification Spectral Lines H Fe Na H Ca H Spectral Classification of Stars Timeline: 1890s Edward C. Pickering (1846-1919) and Williamina P. Fleming
More informationAnalysis of the rich optical iron-line spectrum of the x-ray variable I Zw 1 AGN 1H
Analysis of the rich optical iron-line spectrum of the x-ray variable I Zw 1 AGN 1H0707 495 H Winkler, B Paul Department of Physics, University of Johannesburg, PO Box 524, 2006 Auckland Park, Johannesburg,
More informationAstronomy 102: Stars and Galaxies Final Exam Review Problems Revision 2
Astronomy 102: Stars and Galaxies Final Exam Review Problems Revision 2 Multiple Choice Questions: The first eight questions are multiple choice. Except where explicitly noted, only one answer is correct
More information