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| | Astronomy@Kirkwood IC: Laboratory Exercises---M15 |
 | | After all of the estimated magnitudes are determined, calculate an average apparent magnitude for each of the six RR Lyrae stars. | | | Eventually you will have a table containing eight different values of apparent magnitude for each of the six RR Lyrae stars (that's six measurements on each of the eight photographs). | | | Now, we can assume RR Lyrae stars in general have the same average apparent magnitude. |
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http://www.avalon.net/~bstuder/m15.html
(917 words)
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| | Large Magellanic Cloud Microlensing |
| | The distance distribution of the Sgr RRab, equivalent to about 0.5% of all the MACHO RRab found in the LMC, is overplotted in Figure 3 (we have actually used the reddening independent magnitudes to compute their individual distances because of the heavy differential reddening of the bulge fields). | | | These cuts are optimized to discriminate foreground RR Lyrae from LMC RR Lyrae, blends, and other variable stars. | | | The uncertainty in these individual distances is estimated to be about 10%, with the caveat that the zero point in RR Lyrae absolute magnitudes may be more uncertain (e.g., M |
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http://ecf.hq.eso.org/~ralbrech/sepdec97apjl/975552.html
(3422 words)
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| | [No title] |
| | Starting from the SSCP’s self-similar scaling equations and our knowledge of RR Lyrae stars, we were able to determine uniquely the mass of the Atomic Scale analogues of RR Lyrae stars (helium), the relevant range of principal quantum numbers (n = 7-10) and the relevant angular quantum numbers (l = 0,1). | | | Inherent and practical observational uncertainties that place limits on the quantitative exactitude with which we can test the true degree of self-similarity will be discussed. | | | In order to test the predictions for the RRab subset, which we might also refer to as the n = 10 → 9 and n = 9 → 8 systems, then we will have to rely upon smaller samples of very homogeneous systems observed in environments that maximize uniformity. |
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http://www.amherst.edu/~rloldershaw/newdevyear/2005.htm
(6457 words)
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| | RR Lyrae variable stars |
| | The absolute magnitude of the RR Lyrae variables is known to depend on metallicity, but no general consensus has been reached so far both on the correct slope and on the zero-point of the Mv(RR)-[Fe/H] relation. | | | A large number of research programs at various levels of completion are presently carried out, and new projects are proposed to address the RR Lyrae distance scale and the stellar population issues, as well as the impact of the RR Lyraes on stellar evolution and pulsation theories (see sections 1.4.1, 1.4.2, 1.4.3, and 1.4.4 below). | | | New software tools are being developed, purposely designed to allow the identification of variable stars and to perform period searches and studies of multi periodicities of variable objects. |
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http://www.bo.astro.it/report99/node21.html
(436 words)
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| | OzDASL: Magnitudes of Variable Star RR Lyrae 1198 |
| | For example, Beat Cepheids and Beat RR Lyrae oscillate at more than one frequency. | | | Different classes of variable stars can be located in different regions of a plot of magnitude versus temperature or spectral type. | | | OzDASL: Magnitudes of Variable Star RR Lyrae 1198 |
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http://www.statsci.org/data/oz/rrl1198.html
(749 words)
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| | IMSA Astrophysics: Distance Ladder |
| | To find the distance to the RR Lyrae star, simply determine its apparent visual magnitude, m, and solve the distance modulus equation. | | | For example, we can determine the distance to the RR Lyrae star described above using the mean apparent magnitude (remember, it varies) of 5.81. | | | Unlike Cepheids, whose periodicity is related to its absolute magnitude, RR Lyrae stars have an even simpler relationship with absolute magnitude. |
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http://staff.imsa.edu/science/astro/astrometry/rung3.html
(256 words)
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| | Senior Thesis |
| | Ab-type RR Lyrae stars are those with period’s larger then.4 days and have large amplitude luminosity variations between.5 and 1.5 magnitudes. | | | The plot presented in their paper ranges in magnitude from 13 to 14 where as plot four in this paper ranges in magnitude from 12.7 to about 14 (Clementini et al. | | | C-type RR Lyrae stars is those with shorter periods usually around.4 days and smaller amplitude variation in the luminosity usually under.5 magnitudes (Binney 1998). |
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http://www.msu.edu/user/hickmot1/seniorthesis.htm
(2737 words)
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| | RR Lyrae variable stars |
| | The absolute magnitude of the RR Lyrae's M | | | At present, several research programs at various levels of completion are being carried out. | | | (RR) is known to depend on metallicity: M |
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http://www.bo.astro.it/report01/node19.html
(134 words)
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| | AAVSO: RR Lyrae Ephemerides |
| | RR Lyrae Ephemerides 2005 - pdf file (1.5 MB) | | | Most new browser packages (such as Netscape Communicator) come with this built in. | | | The RR Lyrae Ephemeris is available in Adobe PDF format which requires the Acrobat PDF reader plug-in. |
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http://www.aavso.org/observing/programs/rrlyrae/rrlyrephem.shtml
(82 words)
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| | [46.02] CCD Photometry of RR Lyrae Variables in The Globular Cluster M53 |
| | The mean magnitude of the RR Lyrae variables is | | | [46.02] CCD Photometry of RR Lyrae Variables in The Globular Cluster M53 | | | We present BV CCD photometry for 44 RR Lyrae variables in the metal-poor ([Fe/H] = -1.99) outer halo globular cluster M53 using the data sets obtained with the University of Hawaii 2.2-meter Telescope and the MDM 2.4-meter Hiltner Telescope. |
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http://www.aas.org/publications/baas/v33n2/aas198/366.htm
(187 words)
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| | [No title] |
| | 1991, "CCD Photometry of the RR Lyrae Star SS Leonis", Journal of the AAVSO, 20, 28. | | | Smith, H., "CCD Photometry of Variable Stars in a Sophomore Level Astronomy Course", Journal of the AAVSO, 22, 35. | | | Much of the observing is carried out by students, both graduate students and undergraduates. |
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http://www.pa.msu.edu/astro/observ/research.html
(521 words)
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| | Astronomy Research |
| | In addition to the RR Lyrae work, we have extended the variability search to the fainter magnitudes associated with variable blue stragglers and eclipsing binary systems on the main sequence or sub-giant branch. | | | The importance of the presence of RR Lyrae variables in globular clusters for investigating the physics and evolution of both the variables themselves and the globular clusters in which they occur is well known. | | | Astronomical research in the Physics Department is concentrated in two areas: investigations of the formation and evolution of planetary nebulae, and the study of RR Lyrae variable stars. |
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http://www.physics.uncc.edu/PhysStaff/Graduate/research1/ast.html
(316 words)
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| | RR Lyrae Stars and the Distance to M4 |
| | REMINDER IF YOU ARE USING YOUR OWN GRAPH PAPER: the graph must have the smallest magnitude value (for brightest) at the top of the "y" axis and the largest magnitude value (for dimmest) at the bottom of the "y" axis. | | | The RR Lyrae stars have a mean absolute magnitude (M) of 0.75. | | | Even though they are not very luminous, RR Lyrae variables serve an important function. |
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http://www.astro.washington.edu/labs/clearinghouse/labs/DistM4/m4.html
(1106 words)
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| | Calvin College - Physics and Astronomy |
| | All RR Lyrae stars have a same average absolute magnitude of 0.6. | | | RR Lyrae variable stars are known for having a short period of variability of less than a day in length. | | | RR Lyrae stars are usually found in globular clusters, which is a cluster of stars from the same source that is gravitationally bound to each other. |
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http://www.calvin.edu/academic/phys/observatory/images/Astr212.Fall2002/SWAnd
(697 words)
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| | Office of Public Affairs at Yale - News Release |
| | The QUEST CCD camera was built under the direction of Charles Baltay, Eugene Higgins Professor and chair of physics, and professor of astronomy at Yale. | | | The QUEST camera, which consists of 16 2048x2048 pixel CCDs, is mounted on 1m Schmidt telescope at the Llano del Hato Observatory in Venezuela. | | | SDSS had detected a clump of stars, both RR Lyrae variables and A type stars, that appeared to be the remains of a satellite galaxy that had been accreted by the Milky Way. |
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http://www.yale.edu/opa/newsr/01-01-08-01.all.html
(565 words)
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| | What is an RR Lyrae? |
| | The star RR Lyrae as it appears in the Deep Sky Survey | | | RR Lyraes are much hotter than our Sun. | | | The first known RR Lyrae variable was the star RR Lyrae. |
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http://etacar.umn.edu/~martin/rrlyrae/rrlyrex.htm
(594 words)
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| | AAVSO: RR Lyrae Charts |
| | Please consult the RR Lyrae committee pages for information on how to observe and report observations on these objects. | | | Below is a list of 40 RR Lyrae stars for which we have published new charts. | | | You can search the charts using our online chart search engine. |
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http://www.aavso.org/observing/programs/rrlyrae/rrlyrcharts.shtml
(46 words)
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| | MSN Encarta - Search Results - RR |
| | MSN Encarta - Search Results - RR Home | | | Exclusively for MSN Encarta Premium Subscribers--quickly search thousands of articles from magazines such as Time, Newsweek, The Atlantic Monthly, and Smithsonian. | | | RR Lyrae Star, type of variable star (Star), used in the determination of distances in astronomy. |
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http://ca.encarta.msn.com/RR.html
(132 words)
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| | Catalog of RR Lyrae stars from the SMC |
| | The mean extinction free magnitudes derived for RRab stars are 18.97, 19.45 and 19.73 mag for the I, V and B-bands, respectively. | | | We present the catalog of RR Lyrae stars from the 2.4 square degree of central parts of the Small Magellanic Cloud (SMC). | | | The photometric data were collected during four years of the OGLE-II microlensing survey. |
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http://bulge.princeton.edu/~ogle/ogle2/rrlyr_smc.html
(271 words)
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| | Standard Candle Calibration |
| | Assuming an intrinsic dispersion of 0.14 mag in absolute magnitude, this will determine M | | | If not, it will demonstrate that there is something fundamental that we do not understand about either subdwarfs or RR Lyraes. | | | The period-luminosity relation for Cepheid variables, and the luminosity-metallicity relation for RR Lyrae stars, are fundamental to the determination of distances to the galaxies in nearby clusters and thus, ultimately, to the determination of the expansion age of the universe (c.f. |
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http://www.usno.navy.mil/FAME/science/StandardCandles.html
(665 words)
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| | Re: What does 'RR' stand for in RR Lyrae stars? |
| | There are lots of different classes of variable stars, and each class is named after the first object of its type to be discovered. | | | Most university-level astronomy textbooks will have a lot of information about variable stars (I got the information about the naming business from Abell's "Exploratin of the Universe") as does David Levy's "Observing Variable Stars: A Guide for the Beginner" (1989, Cambridge University Press). | | | Well, as you may know, 'Lyrae' means that the star is in the constellation Lyra, and the variable stars in each constellation are all named in a specific order. |
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http://www.madsci.org/posts/archives/jul99/930832662.As.r.html
(261 words)
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| | Sagittarius Dwarf Galaxy Unlike Milky Way Satellite |
| | Future numerical simulations will assess the feasibility of each of these scenarios. | | | Patrick Cseresnjes and his collaborators compared the period distribution of RR Lyrae stars in Sgr with those of all other dwarf galaxies with a known RR Lyrae population. | | | Stellar evolution theory indicates that RR Lyraes are more than 10 Gigayears old. |
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http://unisci.com/stories/20021/0226021.htm
(729 words)
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| | Research Endeavours (Christine Clement) |
| | Frequency Analysis of the First Overtone RR Lyrae Stars and the Indication for Nonradial Pulsations, Astrophysical Journal, 542, 257-280 | | | Most of my recent work involves the study of RR Lyrae variables. | | | Clement, C. and Shelton, I. New CCD Observations of the RR Lyrae Variables in the Oosterhoff Type II Cluster M9, Astronomical Journal, 118, 453-461. |
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http://www.astro.utoronto.ca/~cclement/papers.html
(1259 words)
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| | [No title] |
| | Click on File Name to review table fields and notes. | | | We present new measurements of the metallicity of 131 RR Lyrae stars in the globular cluster {omega} Centauri, using the hk index of the Caby photometric system. | | | The hk method has distinct advantages over {delta}S and other techniques in determining the metallicity of RR Lyrae stars and has allowed us to obtain the most complete and homogeneous metallicity data to date for the RR Lyrae stars in this cluster. |
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http://xml.gsfc.nasa.gov/archive/journals/AJ/119/1824
(264 words)
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| | RR Lyrae Stars - Cambridge University Press |
| | The absolute magnitude of the RR Lyrae stars; 3. | | | This book reviews our current understanding of RR Lyrae stars. | | | RR Lyrae stars beyond the Milky Way; Glossary of symbols; Short list of journal abbreviations; References; Index. |
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http://www.cup.cam.ac.uk/catalogue/catalogue.asp?ISBN=0521548179
(233 words)
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| | RR Lyr Comparison Table |
| | RR Lyrae stars are also fainter than Cepheids, with absolute magnitudes around +0.7, corresponding to a luminosity about 45 times the Sun's. | | | RR Lyrae stars are valid distance indicators out to more than 200 kpc. | | | A large class of pulsating (amplitude variation about 1 mag) blue giants of anomalous spectral type (A2-F6) with periods of less than 1 day. |
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http://www.csi.uottawa.ca:4321/astronomy/RRLyr_table.html
(191 words)
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| | RR Lyrae - Wikipedia, the free encyclopedia |
| | As RR Lyrae variables are important standard candles, knowing the precise distance of this star is necesssary to determine its luminosity, and hence that of other stars in its class. | | | It has a period of about 13 hours, and oscillates between apparent magnitudes 7 and 8. | | | If accurate, this gives RR Lyrae an absolute magnitude of 0.61, roughly 49 times solar luminosity. |
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http://en.wikipedia.org/wiki/RR_Lyrae
(165 words)
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| | M3 Movies |
| | RR Lyrae often have amplitudes of variation as high as 1 magnitude in V, and even higher in B. The RRab stars (fundamental mode pulsators) are the most numerous and have periods of roughly half a day. | | | RR Lyrae are particularly useful in determining the distance to globular clusters, and have even been used to measure the distance to the magellanic clouds, where the Cepheid distance scale is calibrated. | | | In fact, because globular clusters contain so many RR Lyrae, these variables were once known as "cluster variables." So what are RR Lyrae? |
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http://cfa-www.harvard.edu/~jhartman/M3_movies.html
(680 words)
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| | Etoiles RR Lyrae |
| | Bailey that most of these variables were of a particular type: period less than one day, amplitude of the order of one magnitude. | | | One then deduced that the cause of variation was the same for cepheids and RR Lyrae. | | | At that time, many astronomers, as noted by H.A. Smith, were believing that cepheids are spectroscopic binaries and that their variations due to their binarity. |
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http://webast.ast.obs-mip.fr/people/leborgne/dbRR/rr001en.htm
(489 words)
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| | RR Lyrae |
| | RR Lyrae has a period of 13h 36m and a range of one full magnitude, 7.1 to 8.1. | | | RR Lyrae is the prototype of a class of variables (that is, the ‘main’ star in that category, usually the first star discovered with its particular characteristics). | | | RR Lyrae variables are very old giants which pulsate (that is their outer layer expands and contracts). |
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http://www.dibonsmith.com/lyr_rr.htm
(93 words)
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| | RR Lyrae star |
| | RR Lyrae variables, however, are older, less massive, and fainter (with luminosities typical around 45 Lsun) than Cepheids. | | | Some of them have similar light curves to those of Cepheid variables (earning them the now-obsolete name of cluster Cepheids or short-period Cepheids) and, like Cepheids, obey a period-luminosity relation that enables them to serve as reliable distance indicators. | | | A short-period, yellow or white giant pulsating variable; RR Lyrae stars belong to Population II and are often found globular clusters (hence one of their older names of cluster variables) or elsewhere in the galactic halo. |
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http://www.daviddarling.info/encyclopedia/R/RR_Lyrae_star.html
(268 words)
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| | NGC 6388/NGC 6441 Discussion |
| | The RR Lyrae data is used to help in determining the unusual nature of these clusters and test the models of Sweigart & Catelan (1998). | | | Fourteen of these variables are likely cluster member RR Lyrae and a number of the variables found are likely RR Lyrae. | | | Forty-six of these variables are RR Lyrae stars, most of which are probable cluster members. |
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http://www.noao.edu/noao/staff/pritzl/clusters.html
(1594 words)
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| | [No title] |
| | RR Lyrae: the zero point of temperature and magnitude scales. | | | The Absolute Magnitude and Kinematics of RR Lyrae Stars via Statistical Parallax | | | The Absolute Magnitude and Kinematics of RR Lyrae Stars Via Statistical Parallax |
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http://www.columbia.edu/~fms5/w896.html
(2905 words)
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| | More Research |
| | This work complements my past and present work on determining the RR Lyrae luminosity using a method called statistical parallax. | | | The velocities, positions, and chemical composition of the stars in our Galaxy have "locked in" the memory of the properties of the gas clouds which formed them. | | | An accurate knowledge of the RR Lyrae luminosity makes them "standard candles" -- by simply measuring the apparent brightness of an RR Lyrae, you have determined its distance. |
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http://physics.bgsu.edu/~layden/ASTRO/EDUC/more_research.htm
(1109 words)
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| | The metallicities and kinematics of RR Lyrae variables. I. New observations of local stars |
| | The metallicity distribution of the RR Lyrae stars peaks at [Fe/H]_K_{approx}-1.5, and is narrower than that of the Ryan and Norris (1991AJ....101.1865R) subdwarfs, as expected since the most metal-rich and metal-poor progenitors preferentially appear as stable red and blue horizontal branch stars, rather than as RR Lyrae. | | | The abundance distribution of the local RR Lyrae stars is in excellent agreement with the changing abundance distributions of distant RR Lyrae stars as a function of galactocentric distance, as derived by Suntzeff et al. | | | The metal-rich tail of the RR Lyrae distribution extends to [Fe/H]_K_{approx}0, and a qualitative analysis of the distribution of distances from the galactic plane shows that the stars in this tail (i.e., [Fe/H]_K_>-1.0) are more concentrated to the plane than the more metal-poor stars. |
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http://www.cs.wisc.edu/niagara/data/nasa/AJ_108_1016.xml
(522 words)
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| | Evolution of V79 in M3 |
| | The RR Lyrae variables in type II clusters should switch modes at longer periods, and as a result, their mean periods will be longer than those in the type I clusters. | | | This is the first observed mode switch for an RR Lyrae variable, and it is direct observational evidence for blueward evolution of horizontal-branch stars in the Oosterhoff type I cluster M3. | | | A standard method for investigating the evolution of horizontal-branch stars is to analyze the period changes of RR Lyrae variables in globular clusters. |
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http://ecf.hq.eso.org/~ralbrech/novdec97apjl/975521.html
(2814 words)
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| | Field RR Lyrae calibration |
| | The trigonometric parallaxes of the n-brightest (closest) RR Lyrae stars must be determined in order to calibrate the absolute magnitude as a function of period, and metallicity if the relation between the field and cluster RR Lyrae stars it to be used at the 1% level. | | | The 20 brightest field RR Lyrae stars range from 7.66 mean-light V to about 10.0. |
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http://www.ess.sunysb.edu/simswg/siswg/node39.html
(99 words)
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| | AllRefer.com - RR Lyrae (Astronomy, General) - Encyclopedia |
| | More articles from AllRefer Reference on RR Lyrae | | | You are here : AllRefer.com > Reference > Encyclopedia > Astronomy, General > RR Lyrae | | | AllRefer.com - RR Lyrae (Astronomy, General) - Encyclopedia |
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http://reference.allrefer.com/encyclopedia/X/X-RRLyrae.html
(119 words)
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| | RR Lyrae |
| | Related content from HighBeam Research on: RR Lyrae | | | RR Lyrae variable (The Hutchinson Dictionary of Scientific Biography) | | | Yale researcher identifies stars that give clues to the Milky Way. |
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http://www.infoplease.com/id/A0918266
(89 words)
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| | RR Lyrae variable stars in the CCD/Transit Instrument Survey |
| | We detected a total of 42 RR Lyrae stars to a faint limiting magnitude of V=19. | | | We searched the CCD/Transit Instrument (CTI) survey databases for RR Lyrae variable stars. | | | The resulting survey area covers a large range of both Galactic latitude and longitude, amounting to approximately 50deg^2. |
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http://www.cs.wisc.edu/niagara/data/nasa/AJ_112_742.xml
(185 words)
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| | [101.11] LONEOS RR Lyrae Survey: Early Results |
| | RR Lyrae stars are excellent standard candles for two reasons: they have characteristic lightcurves which make them easily identifiable, and they also have small scatter in their intrinsic brightness. | | | We present lightcurves of several newly discovered RR Lyrae. | | | We also present follow-up photometry with the 3.5-m Apache Point Observatory (APO) and 0.76-m Manastash Ridge Observatory (MRO) to determine the degree of contamination and for the refinement of selection criteria. |
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http://www.aas.org/publications/baas/v33n3/dps2001/772.htm
(209 words)
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| | Chapter 18: Celestial Distances |
| | Since all the RR Lyrae stars in a given cluster have | | | Astronomers noticed that all RR Lyrae stars in a |
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http://www.astro.virginia.edu/~emm8x/astr124/lectures/Lecture_16_files/v3_slide0075.htm
(56 words)
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| | MSN Encarta - Search Results - RR Lyrae Star |
| | RR Lyrae Star, type of variable star, used in the determination of distances in astronomy. | | | MSN Encarta - Search Results - RR Lyrae Star | | | The name derives from the prototype star, discovered in the... |
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http://uk.encarta.msn.com/RR_Lyrae_Star.html
(109 words)
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| | World History :: Encyclopedia Index -- Rr |
| | INDEX OF ARTICLES: Rr Articles are indexed by the first word of the title, including "A," "The," etc. | | | World History :: Encyclopedia Index -- Rr Events Encyclopedia Localities Companies Surnames Shop |
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http://www.worldhistory.com/wiki/Rr.htm
(80 words)
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| | Thomas M. Corwin, Associate Professor |
| | BV Photometry of the RR Lyrae Variables in the Globular Cluster M75" Corwin, T. M., Borissove, J., Ferraro, F. Smith, H. and Raburn, W. "Fourier Decomposition Analysis of the RR Lyrae Light Curves in the Globular Cluster M3" Cacciari, C., Corwin, T. and Carney, B. In preparation. |
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http://www.physics.uncc.edu/PhysStaff/Mike/Corwin.html
(83 words)
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| | Catalogue Selection Page |
| | VizieR Service at Centre de Données astronomiques de Strasbourg | | | Photometry of the ab-type RR Lyrae star V1 (75 rows) | | | Photometry of the ab-type RR Lyrae star V5 (15 rows) |
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http://vizier.cfa.harvard.edu/viz-bin/VizieR?-source=J/AJ/109/618
(182 words)
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