Observational Instruments & Methods 2023-24 Spring PDF

ÖNEMLİ UYARI: Bu sunum İ.Ü. İstanbul Fen Fakültesi Lisans öğrencilerinin eğitimlerine ücretsiz katkı sağlamak amaçlı hazırlanmış olup, bilimsel kaynak olarak gösterilemez, ücretlendirilemez, izinsiz kaydedilemez, kullanılamaz, çoğaltılamaz ve ticari bir ürün haline dönüştürülemez. i : i https://oys....

ÖNEMLİ UYARI: Bu sunum İ.Ü. İstanbul Fen Fakültesi Lisans öğrencilerinin eğitimlerine ücretsiz katkı sağlamak amaçlı hazırlanmış olup, bilimsel kaynak olarak gösterilemez, ücretlendirilemez, izinsiz kaydedilemez, kullanılamaz, çoğaltılamaz ve ticari bir ürün haline dönüştürülemez. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 1 / 72 İ S TA N B U L ÜNİVERSİTESİ OBSERVATIONAL INSTRUMENTS & METHODS 2023-24 SPRING DERS KODU: ASUB3229 (ENROLLED AFTER 2017-2018) DERS KODU: ASUB4195 (ENROLLED BEFORE 2017-2018) i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 2 / 72 Asst. Prof. Can GÜNGÖR: Asst. Prof. Can GÜNGÖR, completed undergraduate and master degrees in the Department of Astronomy and Space Sciences in Science Faculty of Ege University. He obtained his PhD degree with his researches on ‘low mass x-ray binaries’ in the Department of Physics Engineering, Istanbul Technical University in 2016. Between 2015-2016, he worked in Astrophysical Institute and University Observatory, Jena University Germany, as visiting researcher. Between 2016-2017, he carried out his post doc research first in Sabancı University, Faculty of engineering and Natural Sciences, then, between 2017-2019, he worked in Institute of High Energy Physics, Chinese Academy of Sciences where Chinese first X-ray satellite has been operated and then in 2019, he again worked in Sabancı University as post doc researcher. Since 2020, he has been carrying out his research in the Department of Astronomy and Space Sciences at Science Faculty of Istanbul University on observational and computational x-ray astrophysics. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 3 / 72 Lecture Structure Tuesday 13:00 – 16:00 Tuesday 16:00 – 17:00 presentation) (Labs; Repetition, Practice, student Lecture Notes & book passages – will be uploaded. Classes Lecture presentations – will be uploaded after each class. Instructive links, videos etc. Grading System: Mid Term Exam 40% Final Exam 60% Resit Exam (as a second final if necessary !) Course Attendance: 70% -------------------- Home work: Not Mandatory!! HWs will be given before both mid-term & final in which the scores of HWs (5/100) will be added to your exams. Quizes An observation plan for a specific object (5/100) i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 4 / 72 Kaynaklar: 1. Astronomide Gözlem Araç ve Yöntemleri: Derlemeler Prof. Dr. Tansel AK. (Türkçe kaynak - içerik sıralaması için önemli) i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 5 / 72 Kaynaklar: 2. Astronomical Measurement Andy Lawrence i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 6 / 72 Kaynaklar: 3. An Explorer’s Guide to the Universe Astronomical Observations, Astronomy and the Study of Deep Space By Erik Gregersen i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 7 / 72 Kaynaklar: 4. The Principles of Astronomical Telescope Design Jingquan Chen i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 8 / 72 Kaynaklar: 5. To Measure the Sky an Introduction to Observational Astronomy Frederick R. Chromey i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 9 / 72 Lecture Contents: 1. Astronomical Observation & Observatory; Astronomical observations, observatories, finding the best location for an observatory, light pollution etc. what do we observe, effect of atmosphere … 2. Basics of Optics: Optic Laws, refractive index, Fermat’s principle & Snell’s law, critical angle, Paraxial optics, Lenses and mirrors, magnification, prisms, diffraction gratings and spectroscopy, Fabry Perot interferometer, filters … 3. Telescopes: Classes of double mirror telescopes; Cassegrain, Gregorian, Fermat principle & conics, aberration; monochromatic & chromatic, reflecting telescopes, Focal plane types, Side optical elements for telescopes, telescope mounts, telescope mirrors, Domes, Space telescopes, radio telescopes, infrared, x-ray and gamma ray telescopes, gravitational detectors, cosmic ray telescopes … i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 10 / 72 Lecture Contents: 4. Spectrometers: Basic parts of a spectrometers, telescope mounts, designing a spectrometer, spectrometer types, spectrometer types, prism spectrometers, flat filed spectrometers, concave grating spectrometers 5. Detectors: Detector characterization, CCDs … 6. Observations Methods: Plan, photometric, astrometric, spectrographic observations i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 11 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 12 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. Observational values; What kind of values? Brightness (flux, count rate, etc) i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 13 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. Observational values; What kind of values? Brightness (flux, count rate, etc) Colour (Spectrum) i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 14 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. Observational values; What kind of values? Brightness (flux, count rate, etc) Colour (Spectrum) Position (RA, DEC) Proper motion, vertical speed i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 15 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. Observational values; What kind of values? Brightness (flux, count rate, etc) Colour (Spectrum) Position (RA, DEC) Proper motion, vertical speed Time i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 16 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. Bare eyes; How!!!? i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 17 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. Bare eyes; How!!!? Argelander Technique German astronomer F. W. A. Argelander (1799−1875) i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 18 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. Electromagnetic radiation Neutrinos Cosmic rays Meteorites Gravitational waves i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 19 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of stellar objects or a stellar event via bare eyes or by using a technical instruments. Elektromagnetik ışınım i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 20 / 72 i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 21 / 72 i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 22 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. Technical instruments; i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 23 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. Technical instruments; What kind of technical instruments? What kind of techniques? i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 24 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. Technical instruments; What kind of technical instruments? What kind of techniques? Telescopes i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 25 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. Technical instruments; What kind of technical instruments? What kind of techniques? Telescopes Spectrographs i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 26 / 72 1. Astronomical Observation & Observatory; Astronomical Observation: Detecting observational values of celestial objects or a stellar event via bare eyes or by using technical instruments. Technical instruments; What kind of technical instruments? What kind of techniques? Telescopes Spectrographs Detectors; CCD cameras, photometers, photographic plates etc… i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 27 / 72 1. Astronomical Observation & Observatory; Observatory: is a place equipped with specific technical instruments for astronomical observation to observe celestial objects. Ground-based Airborne Space-base Underground-based i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 28 / 72 1. Astronomical Observation & Observatory; Properties of Astronomical Observations: Electromagnetic radiation are detected in an astronomical observation. Astronomical observation is done in a specific location and specific time. To record time and location is one of the most important information. Astronomical events change in time and location of observation is used for precise reductions. It is done for an AIM. So, an astronomer has a scientific goal to answer an open question. It is done by using specific instruments and the instrumental specifications (e.g. detector properties) is important for precise reductions. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 29 / 72 1. Astronomical Observation & Observatory; Observatory: is a place equipped with specific technical instruments for astronomical observation to observe celestial objects. Ground-based Airborne Space-base Underground-based i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 30 / 72 1. Astronomical Observation & Observatory; Observatory: is a place equipped with specific technical instruments for astronomical observation to observe celestial objects. Ground-based Turkish National Observatory i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 31 / 72 1. Astronomical Observation & Observatory; Light Pollution: unwanted or excessive artificial light. The reduction in night sky visibility is a result of “skyglow” upwarddirected light emanating from poorly designed or directed lamps and security floodlights. This wasted light is scattered and reflected by solid or liquid particles in the atmosphere and then returned to the eyes of people on the ground, obliterating their view of the night sky. https://www.lightpollutionmap.info/ i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 32 / 72 1. Astronomical Observation & Observatory; Light pollution also has adverse impacts on birds and other animals. Many migratory birds, for example, fly by night, when light from the stars and Moon helps them navigate. These birds are disoriented by the glare of artificial light as they fly over urban and suburban areas. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 33 / 72 1. Astronomical Observation & Observatory; Unit: magnitude per arcsec squared Paranal/Şili gözlemevi V bandında: 21m.6 La Palma gözlemevi V bandında 21m.9 https://www.lightpollutionmap.info/ i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 34 / 72 1. Astronomical Observation & Observatory; Atmospheric effect: Light is effected by atmosphere via Scattering, absorption, refraction. All of these and the turbulent effects of gas corrupts the quality of the images. The main mechanism of scattering is the Rayleigh scattering which is dispersion of electromagnetic radiation by particles that have a radius less than approximately 0.1 the wavelength of the radiation. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 35 / 72 1. Astronomical Observation & Observatory; Atmospheric effect: Light is effected by atmosphere via Scattering, absorption, refraction. All of these and the turbulent effects of gas corrupts the quality of the images. The main mechanism of scattering is the Rayleigh scattering which is dispersion of electromagnetic radiation by particles that have a radius less than approximately 0.1 the wavelength of the radiation. Molecular number density; a function of temptrature and pressure, so it is a function of altitude; and so it is also related with climate and seasons i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 36 / 72 1. Astronomical Observation & Observatory; Atmospheric effect: Light is effected by atmosphere via Scattering, absorption, refraction. All of these and the turbulent effects of gas corrupts the quality of the images. The main mechanism of scattering is the Rayleigh scattering which is dispersion of electromagnetic radiation by particles that have a radius less than approximately 0.1 the wavelength of the radiation. Mie scattering (non-molecular scattering; aerosol particle scattering) is the scattering from water drops, ice pieces or air pollution. This mechanism is also inversely proportional to wavelength (λ-1). So shorter wavelengths are effected more. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 37 / 72 1. Astronomical Observation & Observatory; Atmospheric effect: Atmospheric turbulences worsen seeing. Seeing: The atmospheric blurring distorts the view of astronomical objects much as ripples in water distort the objects below the surface. The FWHM of the seeing disc (or just "seeing") is usually measured in arcseconds, abbreviated with the symbol (″). A 1.0″ seeing is a good one for average astronomical sites. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 38 / 72 1. Astronomical Observation & Observatory; Atmospheric effect: Atmospheric turbulences worsen seeing. Seeing: The atmospheric blurring distorts the view of astronomical objects much as ripples in water distort the objects below the surface. The FWHM of the seeing disc (or just "seeing") is usually measured in arcseconds, abbreviated with the symbol (″). A 1.0″ seeing is a good one for average astronomical sites. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 39 / 72 1. Astronomical Observation & Observatory; Atmospheric effect: Atmospheric turbulences worsen seeing. Seeing: The atmospheric blurring distorts the view of astronomical objects much as ripples in water distort the objects below the surface. The FWHM of the seeing disc (or just "seeing") is usually measured in arcseconds, abbreviated with the symbol (″). A 1.0″ seeing is a good one for average astronomical sites. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 40 / 72 1. Astronomical Observation & Observatory; Atmospheric effect: Atmospheric turbulences worsen seeing. Seeing: The atmospheric blurring distorts the view of astronomical objects much as ripples in water distort the objects below the surface. The FWHM of the seeing disc (or just "seeing") is usually measured in arcseconds, abbreviated with the symbol (″). A 1.0″ seeing is a good one for average astronomical sites. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 41 / 72 1. Astronomical Observation & Observatory; The resolving power of a telescope: is its ability to produce separate images of two closely spaced objects. The theoretical angular resolving power is given with Rayleigh criteria which is a function of wavelength and the diameter of the telescope. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 42 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 43 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 44 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Higher is better but altitude is not only parameter for a good observatory so we cannot generalize. At the higher altitudes than inversion layer of atmosphere, the molecules are more sparse (rare) and it is better to build an observatory higher than inversion layer of atmosphere where is around 2000m high (depending on season etc.). i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 45 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Higher is better but altitude is not only parameter for a good observatory so we cannot generalize. At the higher altitudes than inversion layer of atmosphere, the molecules are more sparse (rare) and it is better to build an observatory higher than inversion layer of atmosphere where is around 2000m high (depending on season etc.). Conclusion, better to locate higher than 2000m altitude. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 46 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 47 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Average clear sky count must be at least 200. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 48 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Average clear sky count must be at least 200. !! ‘Clear sky’ definition might be different for meteorologists and astronomers. So you must be very careful to use meteorological clear sky charts. Cloudiness must be taken into account. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 49 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Average clear sky count must be at least 200. !! ‘Clear sky’ definition might be different for meteorologists and astronomers. So you must be very careful to use meteorological clear sky charts. Cloudiness must be taken into account. The best study to define cloudiness is to use satellite observations in the energy band of 10.7 micron (infrared) and 6.7 micron (water vapour) wavelength and to do computer simulations along seasons. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 50 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 51 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity The concentration of water vapor present in the air. Water mass in a unit volume. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 52 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity The concentration of water vapor present in the air. Water mass in a unit volume. Precipitable water vapour (PWV), is expressed in terms of the height to which that water substance would stand if completely condensed and collected in a vessel of the same unit. For example the height of 1lt water in a 1m2 area is 1mm, PWV=1mm. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 53 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity The concentration of water vapor present in the air. Water mass in a unit volume. Precipitable water vapour (PWV), is expressed in terms of the height to which that water substance would stand if completely condensed and collected in a vessel of the same unit. For example the height of 1lt water in a 1m2 area is 1mm, PWV=1mm. Optical observations PWV < 5mm i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 54 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity The concentration of water vapor present in the air. Water mass in a unit volume. Precipitable water vapour (PWV), is expressed in terms of the height to which that water substance would stand if completely condensed and collected in a vessel of the same unit. For example the height of 1lt water in a 1m2 area is 1mm, PWV=1mm. Optical observations PWV < 5mm Infrared PWV < 3mm i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 55 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity The concentration of water vapor present in the air. Water mass in a unit volume. Precipitable water vapour (PWV), is expressed in terms of the height to which that water substance would stand if completely condensed and collected in a vessel of the same unit. For example the height of 1lt water in a 1m2 area is 1mm, PWV=1mm. Optical observations PWV < 5mm Infrared PWV < 3mm Microwave < 2mm i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 56 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 57 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Aerosol: Solid or water particles in a gas with sizes smaller than 10 micron. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 58 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Aerosol: Solid or water particles in a gas with sizes smaller than 10 micron. Increase scattering and absorbtion. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 59 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Aerosol: Solid or water particles in a gas with sizes smaller than 10 micron. Increase scattering and absorbtion. Negative effects on telescope mirrors. Shorten the cleaning periods of mirrors. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 60 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Aerosol: Solid or water particles in a gas with sizes smaller than 10 micron. Increase scattering and absorbtion. Negative effects on telescope mirrors. Shorten the cleaning periods of mirrors. Unit is Aerosol index. Must be fewer than 0.5 for a good observatory. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 61 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Light Pollution i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 62 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Light Pollution Average wind speed (and direction) i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 63 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Light Pollution Average wind speed (and direction) Create vibration on telescopes. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 64 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Light Pollution Average wind speed (and direction) Create vibration on telescopes. Max value is around 40-60 km/h i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 65 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Light Pollution Average wind speed (and direction) Seeing i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 66 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Light Pollution Average wind speed (and direction) Seeing Must be less than 1”. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 67 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Light Pollution Average wind speed (and direction) Seeing Atmospheric Turbulence i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 68 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Light Pollution Average wind speed (and direction) Seeing Atmospheric Turbulence To obtain turbulence profiles along height is especially important for adaptive optics. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 69 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Light Pollution Average wind speed (and direction) Seeing Atmospheric Turbulence To obtain turbulence profiles along height is especially important for adaptive optics. It’s measured via balloons or MASS, SCIDAR type instruments. MASS; Multi Aperture Scintillation Sensor -> looking for volunteer SCIDAR; scintillation detection and ranging -> looking for volunteer i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 70 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Light Pollution Average wind speed (and direction) Seeing Atmospheric Turbulence Seismic properties i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 71 / 72 1. Astronomical Observation & Observatory; Choosing the right location for an observatory: Altitude Meteorological conditions, Cloudiness or clear sky counts Absolute humidity, relative humidity Dust & Aerosol Light Pollution Average wind speed (and direction) Seeing Atmospheric Turbulence Seismic properties Strategical parameters – Logistic etc. i : i https://oys. stanbul.edu.tr/uploads/mater als/bd01bbb909c482635fa24f9d27e76077.pptx 26.03.2024 21 40 Sayfa 72 / 72