Wyniki wyszukiwania - Biblioteka Nauki

1

On the Atmospheric Extinction Reduction Procedure in Multiband Wide-Field Photometric Surveys

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Zakharov A. , Mironov A. , Biryukov A. , Kroussanova N. , Prokhorov M. , Beskin G. , Karpov S. , Bondar S. , Ivanov E. , Perkov A. , Sasyuk V.

Acta Astronomica

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2015

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tom Vol. 65, No. 2

197--204

EN

We propose an improved method for the atmospheric extinction reduction within optical photometry. Our method is based on the simultaneous multicolor observations of photometric standards. Such data are now available within the modern wide-field sky surveys and contain a large amount of information about instant atmospheric conditions. So, it became possible to estimate the extinction parameters on the basis of a quite short observational dataset and, hence, to trace the rapid stars twinkling accurately. Having been developed for a new MiniMegaTORTORa observational system, the proposed method can be adopted for a wide range of modern observational programs.

2

Unified gravimetric reference frame for Polish IGS/EPN stations and geodynamic test fields

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Walo J. , Olszak T. , Pachuta A. , Próchniewicz D. , Szpunar R.

Reports on Geodesy

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2010

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tom z. 1/88

105-113

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Application of the global geopotential models for determination of the levelling normal correction

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Marganski S. , Kalinczuk-Stanałowska K. , Olszak T.

Reports on Geodesy

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2010

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tom z. 1/88

115-120

EN

Vertical networks in Poland are processed in the normal heights system called Kronstatt'86. Levelling evaluation of high precision measurements requires a determinations of normal levelling corrections, based on gravity Faye's anomalies. The purposes of the paper is to analyze the possibility of using in this computations the anomalies generated from global geopotential models while maintaining accuracy analysis which indicate a possible accuracy of Faye's anomalies. Author have compared gravity anomalies obtained directly from measurements with gravity anomalies generated from different global geopotential models EGM96, PGM96, EGM2008. Authors have prospered an algorithm of gravity anomalies computation on geoid surface after free-air moving anomalies from geopotential models. Comparison was made on points of vertical network located in medium-hill areas (around Starachowice near Kielce) and lowland (around Gostyn and Grudziadz) and on others test fields in Poland. The ability to use the geopotential models depends on their resultation. As a result of analysis concluded that only in the plain and lowland areas is possible to use data from global geopotential models with resolution above degree 720.

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OGLE Collection of Star Clusters. New Objects in the Outskirts of the Large Magellanic Cloud

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Sitek M. , Szymański M. K. , Skowron D. M. , Udalski A. , Kostrzewa-Rutkowska Z. , Skowron J. , Karczmarek P. , Cieślar M. , Wyrzykowski Ł. , Kozłowski S. , Pietrukowicz P. , Soszyński I. , Mróz P. , Pawlak M. , Poleski R. , Ulaczyk K.

Acta Astronomica

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2016

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tom Vol. 66, No. 3

255--267

EN

The Magellanic System (MS), consisting of the Large Magellanic Cloud (LMC), the Small Magellanic Cloud (SMC) and the Magellanic Bridge (MBR), contains diverse sample of star clusters. Their spatial distribution, ages and chemical abundances may provide important information about the history of formation of the whole System. We use deep photometric maps derived from the images collected during the fourth phase of the Optical Gravitational Lensing Experiment (OGLE-IV) to construct the most complete catalog of star clusters in the Large Magellanic Cloud using the homogeneous photometric data. In this paper we present the collection of star clusters found in the area of about 225 square degrees in the outer regions of the LMC. Our sample contains 679 visually identified star cluster candidates, 226 of which were not listed in any of the previously published catalogs. The new clusters are mainly young small open clusters or clusters similar to associations.

5

The All Sky Automated Survey. Catalog of Variable Stars. V. Declinations 0° - +28° of the Northern Hemisphere

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Pojmański G. , Pilecki B. , Szczygieł D.

Acta Astronomica

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2005

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tom Vol. 55, No. 3

275--301

EN

This paper contains the fifth part of the Catalog of Variable Stars created from the V-band photometric data collected by 9°×9° camera of the All Sky Automated Survey. Preliminary list of variable stars found in the fields located between declination 0° and +28° of the northern hemisphere is presented. 11 509 stars brighter than V=15 mag were found to be variable (2 482 eclipsing, 1 397 regularly pulsating, 318 Miras and 7 310 other stars). Automated algorithm taking into account light curve properties (period, Fourier coefficients) and other available data (2MASS colors, IRAS fluxes) was applied to roughly classify the objects. This paper concludes our preliminary efforts to detect variable stars brighter than V≈14 mag over the sky south of declination +28°. A short summary of the current ASAS Catalog of Variable Stars is presented and links to the on-line data are provided. All the photometric data are available over the INTERNET at http://www.astrouw.edu.pl/~gp/asas/asas.html or http://archive.princeton.edu/~asas

6

Photometric Maps Based on the OGLE-III Shallow Survey in the Large Magellanic Cloud

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Ulaczyk K. , Szymański M. K. , Udalski A. , Kubiak M. , Pietrzyński G. , Soszyński I. , Wyrzykowski Ł. , Poleski R. , Gieren W. , Walker A. R. , Garcia-Varela A.

Acta Astronomica

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2012

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tom Vol. 62, No. 3

247--268

EN

We present photometric maps based on data from the shallow survey in the Large Magellanic Cloud performed as the supplementary project during the third phase of the Optical Gravitational Lensing Experiment. They cover about 40 square degrees in the LMC and contain mean calibrated VI photometry and astrometry of about 1.7 million stars. The magnitudes of the registered objects range from 9.1 to 18.5. We discuss the quality of data and present color-magnitude diagrams of selected fields. The maps together with the main LMC photometric maps are available to the astronomical community from the OGLE Internet archive.

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Use of information and communication technology to access tourist information and services: The results of research conducted among Polish tourists in Małopolska Voivodeship

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Pawłowska-Legwand A.

Turyzm

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2019

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tom 29

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nr 2

105-112

EN

Information and communication technology (ICT) is widely used to access tourist information and services, and as a result using digital tools and sources influences tourist behaviour. The main goal of this paper, based on research, is to describe the behaviours and opinions of tourists who used ICT before travelling. The results include the evaluation of the usefulness of digital tools from a tourist’s point of view, and indicates that tourists are interested in using ICT. Respondents aged over 35, who are living in cities and have had at least secondary education or a university degree, are more active users of digital tools. Websites, mobile applications and other ICT uses have been treated by respondents primarily as a source of tourist information in its widest sense, and a tool which facilitates the process of planning travel routes and purchasing travel-related services. Social media, which facilitate sharing travel-related content, also have a major significance.

8

Investor Relations & Importance in the Global Financial Market

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Dziawgo D.

Equilibrium. Quarterly Journal of Economics and Economic Policy

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2012

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tom 7

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nr 2

EN

The aim of the elaboration is to draw attention to selected aspects of investor relations importance for capital market functioning to increase the quality of communication with investors in the global financial market.The article presents the importance of investor relations from a macroeconomic and microeconomic point of view. The theory was complemented with selected surveys results.The surveys were conducted by the author on a sample of individual investors, stock-quoted companies and sell-side analysts on Polish capital market between June 2009 – March 2010. In the article, description method, comparison method, case study and questionnaire method were used.

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Preferencje i zachowania komunikacyjne mieszkańców miast i gmin aglomeracji miejskich na przykładzie Gdyni, Sopotu, Rumi i Kosakowa

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Hebel K. , Grzelec K.

Transport Miejski i Regionalny

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2004

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tom nr 6

9-15

PL

Porównanie wyników badań marketingowych preferencji i zachowań komunikacyjnych mieszkańców z czterech miast i gmin aglomeracji miejskich. Badania przeprowadzono w latach 2001 - 2003 metodą wywiadu bezpośredniego.

EN

The comparison of marketing studies related to preferences and travel behaviour of inhabitants living in four towns of Gdynia agglomeration. The studies have been carried on 2001 - 2003 using direct contact method.

10

The All Sky Automated Survey. The Catalog of Bright Variable Stars in the I-band, South of Declination +28°

80%

Sitek M. , Pojmański G.

Acta Astronomica

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2014

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tom Vol. 64, No. 2

115--123

EN

This paper presents the results of our extensive search for the bright variable stars in approximately 30 000 square degrees of the south sky in the I-band data collected by 9°×9° camera of the All Sky Automated Survey between 2002 and 2009. Lists of over 27 000 variable stars brighter than 9 mag at maximum light, with amplitudes ranging from 0.02 mag to 7 mag and variability time-scales from hours to years, as well as corresponding light curves are provided. Automated classification algorithm based on stellar properties (period, Fourier coefficients, 2MASS J, H, K, colors, ASAS V-band data) was used to roughly classify objects. Despite low spatial resolution of the ASAS data (&assymp;15'') we cross-identified all objects with other available data sources. Coordinates of the most probable 2MASS counterparts are provided. 27 705 stars brighter than I=9$ mag were found to be variable, of which 7842 objects were detected to be variable for the first time. Brief statistics and discussion of the presented data is provided. All the photometric data is available over the Internet at http://www.astrouw.edu.pl/~gp/asas/AsasBrightI.html

11

Supernovae and Other Transients in the OGLE-IV Magellanic Bridge Data

80%

Kozłowski S. , Udalski A. , Wyrzykowski Ł. , Poleski R. , Pietrukowicz P. , Skowron J. , Szymański M. K. , Kubiak M. , Pietrzyński G. , Soszyński I. , Ulaczyk K.

Acta Astronomica

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2013

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tom Vol. 63, No. 1

1--19

EN

We analyze two years (mid-2010 to mid-2012) of OGLE-IV data covering ≈65 deg2 of the Magellanic Bridge (the area between the Magellanic Clouds) and find 130 transient events including 126 supernovae (SNe), two foreground dwarf novae and another two SNe-like transients that turned out to be active galactic nuclei (AGNs). We show our SNe detection efficiency as a function of SN peak magnitude based on available SNe rate estimates. It is 100% for SNe peak magnitudes I<18.8 mag and drops to 50% at I≈19.7 mag. With our current observing area between and around the Magellanic Clouds (≈600 deg2), we expect to find 24 SNe peaking above I<18 mag, 100 above I<19 mag, and 340 above I<20 mag, annually. We briefly introduce our on-line near-real-time detection system for SNe and other transients, the OGLE Transient Detection System.

12

The All Sky Automated Survey. The Catalog of Variable Stars. II. 0h-6h Quarter of the Southern Hemisphere

80%

Pojmański G.

Acta Astronomica

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2002

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tom Vol. 52, No. 4

397--427

EN

This paper describes the first part of the photometric data from the 9°×9° ASAS camera monitoring the whole southern hemisphere in the V-band. Data acquisition and reduction pipeline are described and preliminary list of variable stars presented. Over 1 300 000 stars brighter than V=15 mag on 10 000 frames were analyzed and 3126 were found to be variable (1055 eclipsing, 770 regularly pulsating, 132 Mira and 1169 other, mostly SR, IR and LPV stars). Periodic light curves have been classified using the fully automated algorithm, which is described in detail. Basic photometric properties are presented in the tables and exemplary light curves are printed for reference. All photometric data are available over the Internet at http://www.astrouw.edu.pl/~gp/asas/asas.html or http://archive.princeton.edu/~asas.

13

Robust Filtering of Artifacts in Difference Imaging for Rapid Transients Detection

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Klencki J. , Wyrzykowski Ł. , Kostrzewa-Rutkowska Z. , Udalski A.

Acta Astronomica

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2016

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tom Vol. 66, No. 1

15--29

EN

Real-time analysis and classification of observational data collected within synoptic sky surveys is a huge challenge due to constant growth of data volumes. Machine learning techniques are often applied in order to perform this task automatically. The current bottleneck of transients detection in most surveys is the process of filtering numerous artifacts from candidate detection. We present a new method for automated artifact filtering based on hierarchical unsupervised classifier employing Self-Organizing Maps (SOMs). The system accepts 97% of real transients and removes 97.5% of artifacts when tested on the OGLE-IV Transient Detection System. The improvement of the artifacts filtering allows for single-frame-based detection of transients within OGLE-IV, which now alerts on transient discoveries in less than 15 minutes from the image acquisition.

14

The Optical Gravitational Lensing Experiment. OGLE-III Photometric Maps of the Galactic Bulge Fields

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Szymański M. K. , Udalski A. , Soszyński I. , Kubiak M. , Pietrzyński G. , Poleski R. , Wyrzykowski Ł. , Ulaczyk K.

Acta Astronomica

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2011

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tom Vol. 61, No. 2

83--102

EN

We present OGLE-III Photometric Maps of the Galactic bulge fields observed during the third phase of the OGLE project. This paper describes the last, concluding set of maps based on OGLE-III data. The maps contain precise, calibrated VI photometry of about 340 million stars from 267 fields in the Galactic bulge observed during entire OGLE-III phase (2002-2009), covering about 92 square degrees in the sky. Precise astrometry of these objects is also provided. We briefly discuss the photometry procedures and the quality of the data. We also present sample data and color-magnitude diagrams of the observed fields. All photometric data are available to the astronomical community from the OGLE Internet archive.

15

OGLE Collection of Star Clusters. New Objects in the Magellanic Bridge and the Outskirts of the Small Magellanic Cloud

80%

Sitek M. , Szymański M. K. , Udalski A. , Skowron D. M. , Kostrzewa-Rutkowska Z. , Skowron J. , Karczmarek P. , Cieślar M. , Wyrzykowski Ł. , Kozłowski S. , Pietrukowicz P. , Soszyński I. , Mróz P. , Pawlak M. , Poleski R. , Ulaczyk K.

Acta Astronomica

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2017

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tom Vol. 67, No. 4

363--378

EN

The Magellanic System (MS) encompasses the nearest neighbors of the Milky Way, the Large (LMC) and Small (SMC) Magellanic Clouds, and the Magellanic Bridge (MBR). This system contains a diverse sample of star clusters. Their parameters, such as the spatial distribution, chemical composition and age distribution yield important information about the formation scenario of the whole Magellanic System. Using deep photometric maps compiled in the fourth phase of the Optical Gravitational Lensing Experiment (OGLE-IV) we present the most complete catalog of star clusters in the Magellanic System ever constructed from homogeneous, long time-scale photometric data. In this second paper of the series, we show the collection of star clusters found in the area of about 360 square degrees in the MBR and in the outer regions of the SMC. Our sample contains 198 visually identified star cluster candidates, 75 of which were not listed in any of the previously published catalogs. The new discoveries are mainly young small open clusters or clusters similar to associations.

16

OGLE-IV Real-Time Transient Search

80%

Wyrzykowski Ł. , Kostrzewa-Rutkowska Z. , Kozłowski S. , Udalski A. , Poleski R. , Skowron J. , Blagorodnova N. , Kubiak M. , Szymański M. K. , Pietrzyński G. , Soszyński I. , Ulaczyk K. , Pietrukowicz P. , Mróz M.

Acta Astronomica

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2014

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tom Vol. 64, No. 3

197--232

EN

We present the design and first results of a real-time search for transients within the 650 sq. deg. area around the Magellanic Clouds, conducted as part of the OGLE-IV project and aimed at detecting supernovae, novae and other events. The average sampling of about four days from September to May, yielded a detection of 238 transients in 2012/2013 and 2013/2014 seasons. The superb photometric and astrometric quality of the OGLE data allows for numerous applications of the discovered transients. We use this sample to prepare and train a Machine Learning-based automated classifier for early light curves, which distinguishes major classes of transients with more than 80% of correct answers. Spectroscopically classified 49 supernovae Type Ia are used to construct a Hubble Diagram with statistical scatter of about 0.3 mag and fill the least populated region of the redshifts range in the Union sample. We investigate the influence of host galaxy environments on supernovae statistics and find the mean host extinction of AI=0.19±0.10 mag and AV=0.39±0.21 mag based on a subsample of supernovae Type Ia. We show that the positional accuracy of the survey is of the order of 0.5 pixels (0.13'') and that the OGLE-IV Transient Detection System is capable of detecting transients within the nuclei of galaxies. We present a few interesting cases of nuclear transients of unknown type. All data on the OGLE transients are made publicly available to the astronomical community via the OGLE website.

17

The Qatar Exoplanet Survey

80%

Alsubai K. A. , Parley N. R. , Bramich D. M. , Horne K. , Collier Cameron A. , West R. G. , Sorensen M. P. , Pollacco D. , Smith J. C. , Fors O.

Acta Astronomica

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2013

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tom Vol. 63, No. 4

465--480

EN

The Qatar Exoplanet Survey (QES) is discovering hot Jupiters and aims to discover hot Saturns and hot Neptunes that transit in front of relatively bright host stars. QES currently operates a robotic wide-angle camera system to identify promising transiting exoplanet candidates among which are the confirmed exoplanets Qatar 1b and 2b. This paper describes the first generation QES instrument, observing strategy, data reduction techniques, and follow-up procedures. The QES cameras in New Mexico complement the SuperWASP cameras in the Canary Islands and South Africa, and we have developed tools to enable the QES images and light curves to be archived and analysed using the same methods developed for the SuperWASP datasets. With its larger aperture, finer pixel scale, and comparable field of view, and with plans to deploy similar systems at two further sites, the QES, in collaboration with SuperWASP, should help to speed the discovery of smaller radius planets transiting bright stars in northern skies.

18

Light Curves of Symbiotic Stars in Massive Photometric Surveys II. S and D'-Type Systems

80%

Gromadzki M. , Mikołajewska J. , Soszyński I.

Acta Astronomica

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2013

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tom Vol. 63, No. 4

405--428

EN

We present results of period analysis of ASAS, MACHO and OGLE light curves of 79 symbiotic stars classified as S and D'-type. The light curves of 58 objects show variations with the orbital period. In case of 34 objects, orbital periods are estimated for the first time, which increases the number of symbiotic stars with known orbital periods by about 64%. The light curves of 46 objects show, in addition to the long-term or/and orbital variations, short-term variations with time scales of 50-200 days most likely due to stellar pulsations of the cool giant component. We also report eclipse-like minima and outbursts present in many of the light curves.

19

The All Sky Automated Survey. Catalog of Variable Stars. IV. 18h-24h Quarter of the Southern Hemisphere

80%

Pojmański G. , Maciejewski G.

Acta Astronomica

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2005

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tom Vol. 55, No. 1

97--122

EN

In this paper we present the fourth part of the photometric data from the 9ox9o ASAS camera monitoring the whole southern hemisphere in V-band. Preliminary list (based on observations obtained since January 2001) of variable stars located between RA 18h and 24h is released. 10311 stars brighter than V=15 mag were found to be variable (1641 eclipsing, 1116 regularly pulsating, 938 Mira-type and 6616 other stars). Light curves have been classified using the automated algorithm taking into account periods, amplitudes, Fourier coefficients of the light curves, 2MASS colors and IRAS infrared fluxes. Basic photometric properties are presented in the tables and some examples of thumbnail light curves are printed for reference. All photometric data are available over the INTERNET at http://www.astrouw.edu.pl/~gp/asas/asas.html or http://archive.princeton.edu/~asas

20

Using All-Sky Surveys to Find Planetary Transits

80%

Pepper J. , Gould A. , DePoy D. L.

Acta Astronomica

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2003

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tom Vol. 56, No. 3

213--228

EN

Transits of bright stars offer a unique opportunity to study detailed properties of extrasolar planets that cannot be determined through radial-velocity observations. We propose a new technique to find such systems using all-sky small-aperture transit surveys. We derive a general formula for the number of stars that can be probed for such systems as a function of the characteristics of the star, the planet, and the survey. We use this formula to derive the optimal telescope design for finding transits of bright stars: a 2 inch "telescope" with a 4k×4k camera.