Lab 4: Differential Photometry of an Extrasolar Planetary Transit

Size: px
Start display at page:

Download "Lab 4: Differential Photometry of an Extrasolar Planetary Transit"

Transcription

1 Lab 4: Differential Photometry of an Extrasolar Planetary Transit Neil Lender 1, Dipesh Bhattarai 2, Sean Lockwood 3 December 3, 2007 Abstract An upward change in brightness of 3.97 ± 0.29 millimags in the XO target star was detected using differential photometry near 7:30 UT on November 23, This indicates an extrasolar planet of radius ± times the radius of the target star made an egress from the target star s disk at about this time. Observations with the telescope were made too late to catch ingress; however, changes in relative brightness that are believed to be instrumental occurred at 6:14 UT when a temporary change of filters and focus was made. This in combination with pointing data suggests there may be a fine-level focusing problem with the telescope, making it inadvisable to change filters on the Perkins during future differential photometry measurements. 1. Introduction This project s aim was to detect an extrasolar planet in orbit about an XO target star by means of detecting a change in brightness of the star before and after the planet s transit. 1 nlender@bu.edu 2 dipesh@bu.edu 3 lockwood@bu.edu This change in brightness is very minute even for Jupiter-sized planets, so measuring it requires use of differential photometry. Differential photometry accounts for atmospheric changes during measurement by comparing the brightness of the target star with the brightness of one or more non-target stars also in the images. Typically aperture photometry is used on all relevant stars with sky annulus background removal for high accuracy and precision. It should be noted that measurements of this type have a selection bias towards large planets, as they block more of their star s light. It also has a selection bias for planets close to their stars because they are statistically more likely to have star transits in Earth s line of sight. However, these biases are largely shared by the other form of exo-planet detection, gravitational wobbling, so with present technology they are mostly unavoidable. 2. Observations The possible transit of the XO target was observed between 5:11 UT and 8:27 UT using the R filter and subframe second exposures were taken in the R filter, and readout time was approximately 6 seconds per exposure. The proportion of readout time was large because was taken that the CCD was never saturated, meaning it could only expose for about 10 seconds at a time. The exposures were taken in groups, requiring a manual restart after each set of 25 images. After 225 images, at 6:14 UT, second exposures were taken in the B filter before a switch back to the R filter. It was later determined that so few images did not provide enough signal to detect the change in B magnitude, however the switch to B may have jiggled

2 2 the instrument causing a break in relative photometry between the first 225 images and the later images. Fig. 1. An overscan, bias, and flat calibrated image from the transit. This is the first image, taken at 5:11 UT. 3. Analysis The 675 measurements of the XO target in the R filter taken between 5 and 9 UT were used to verify the existence of an extrasolar planet. This analysis was extremely sensitive to small errors as the difference in brightness during occultation is only tenths of a percent. Differential photometry was used on the target star and five other bright stars or double stars in the image to reach such precise measurements. The first step was to clean the images, subtracting the overscan and bias, and dividing out the flat. The bias was overscan subtracted as well, and the flat was overscan and bias subtracted before normalization. Figure 1 is an example of one of these cleaned images. The next step was the inspection of one of these images for bright point sources. Astrolib s find routine was used on one cleaned image to find the centroids of the six brightest point sources. The brightest of these was the target star, and the relative positions of the other five with respect to the target were calculated. Because the tracking was not perfect, though it was very good, find was applied again to each image to get the exact centroid of the target star. The other star centroids were located by dead reckoning from the target using the relative positions. Having located the centroid of each star in each cleaned image, IDL was used to apply simple aperture photometry. A very large circular aperture was chosen for each star so that the aperture s edge was just beyond the point where the star s point spread function (or both PSFs of a double) became indistinguishable from the background sky. The sky annulus began at the edge of the aperture and ended at twice the radius of the aperture. The pixels within the sky aperture were plotted in a histogram, and a Gaussian was fit onto that Histogram to find the median pixel value of the sky. This value was multiplied by the number of pixels within the star s annulus and subtracted off of the raw flux of the star to determine the real flux of each star. Figure 2 shows a scatter plot of the brightest non-target star s flux against the sum of the flux of all other non-targets. This shows that our relative photometry kept to a very tight ratio throughout. The absolute brightnesses of the stars varied by about 6%, which would have been far too much for this detection had we not used relative photometry. The real flux of the target star was divided by the total real flux of the non-target stars for each image to make a ratio. If the relative brightnesses of the stars were to remain constant, this

3 3 Fig. 2. This figure compares the brightness of the brightest non-target star to the sum of the brightness of the others. It shows that relative photometry (errors of order width of line) will be much more precise than absolute photometry (errors of order total spread in data) in these conditions. ratio should remain constant. The ratio is dependent on relative brightness, so it is largely immune to atmospheric effects, and because the aperture radii were very large, changes in seeing also will have little effect on the ratio. This ratio is plotted against time in figure 3 (Large points with error bars represents bins of 75, the red line is a 100 point smooth). Even though the noise is still significant, a jump upwards in the brightness of the target star is visible around 7.5 hours UT, corresponding with the expected egress time. Also noticeable is a jump downwards in brightness around 6.2 hours UT. This corresponds with our attempt to image the XO target in the B filter, which may have jiggled our instrument and changed the ratio somehow. It is thought that the focus control may not report the true focus and that the focus was not changed back to exactly where it was. This is supported by figure 4, which shows the declination the telescope believed it was pointing at. Notice that there is a steep jump coincident with the change in filters followed by a change in character of the curve. A change in focus would move the images of the stars on the detector and might cause this effect. The numbers involved are very precise, and the slightest change in the instrument may have been enough to visibly throw them off. Because of this, it is wise to compare the flux from between the B filter debacle and the egress to the flux from after the egress to find changes in relative brightness. The data in bins 4, 5, and 6 were used for pre-egress, and the data from bins 8 and 9 were used for post-egress, with a reasonable certainty that egress occurred during bin 7. Unfortunately, there is no evidence for an ingress near the beginning of the data set, meaning that we probably just missed it or did not catch enough of it to actually see it. The downward jump in flux at 6:14 UT is almost certainly not the ingress as it was at the incorrect time, and was probably caused by the jiggling. 4. Results Analysis of the two previously mentioned windows leads to the following results. Errors are estimated using the standard deviation of the data points and dividing by N. The pre-egress and post-egress flux ratios were ± and ± respectively. Carrying the errors through properly, the flux ratio while the planet occults the star is ± and the difference in magnitude is 3.97 ± 0.29 millimags. This means that the radius of the planet is ± times the radius of the star, assuming that the planet blocks all light and emits none.

4 4 Fig. 3. The telescope s declination angle over time. Note the sudden jump and change in character at 6:14 UT, coincident with the use of the B filter. The more consistent drifting near the end is believed to result from pointing compensation for atmospheric refraction. In addition, there is reason to believe that there is a problem with the focusing on the telescope. The changes in focus involved in using the B filter disrupted the relative photometry and pointing as shown in figures 3 and 4. There also seemed to be some abnormalities involving the relative focuses between filters that we noticed during observations, especially involving the I filter and the relatively large changes in focus involved with using it.

5 5 Fig. 4. The relative brightness of the target over time. Note the change caused by the filter jiggle around 6:14 UT, and the change caused by the egress around 7:30 UT. The line is a 75 point smooth of the data, and the large points with error bars (9 total) represent bins of 75 data points (data was observed in groups of 25 points). For statistics, Bins 4, 5, 6 are used for pre-egress and Bins 8 and 9 are used for post egress.

Lab 4 Radial Velocity Determination of Membership in Open Clusters

Lab 4 Radial Velocity Determination of Membership in Open Clusters Lab 4 Radial Velocity Determination of Membership in Open Clusters Sean Lockwood 1, Dipesh Bhattarai 2, Neil Lender 3 December 2, 2007 Abstract We used the Doppler velocity of 29 stars in the open clusters

More information

Transiting Exoplanet in the Near Infra-red for the XO-3 System

Transiting Exoplanet in the Near Infra-red for the XO-3 System Transiting Exoplanet in the Near Infra-red for the XO-3 System Nathaniel Rodriguez August 26, 2009 Abstract Our research this summer focused on determining if sufficient precision could be gained from

More information

Lecture 8. October 25, 2017 Lab 5

Lecture 8. October 25, 2017 Lab 5 Lecture 8 October 25, 2017 Lab 5 News Lab 2 & 3 Handed back next week (I hope). Lab 4 Due today Lab 5 (Transiting Exoplanets) Handed out and observing will start Friday. Due November 8 (or later) Stellar

More information

Detection of Exoplanets Using the Transit Method

Detection of Exoplanets Using the Transit Method Detection of Exoplanets Using the Transit Method De nnis A fanase v, T h e Geo rg e W a s h i n g t o n Un i vers i t y, Washington, DC 20052 dennisafa@gwu.edu Abstract I conducted differential photometry

More information

You, too, can make useful and beautiful astronomical images at Mees: Lesson 3

You, too, can make useful and beautiful astronomical images at Mees: Lesson 3 You, too, can make useful and beautiful astronomical images at Mees: Lesson 3 Calibration and data reduction Useful references, besides Lessons 1 and 2: The AST 142 Projects manual: http://www.pas.rochester.edu/~dmw/ast142/projects/project.pdf

More information

Observations of Transiting Exoplanets with Differential Photometry

Observations of Transiting Exoplanets with Differential Photometry Manuscript accepted by the Scientific Terrapin, Dec 2011 Observations of Transiting Exoplanets with Differential Photometry Brett Morris University of Maryland bmorris3@astro.umd.edu ABSTRACT Preliminary

More information

Photometry with Iris Photometry with Iris

Photometry with Iris Photometry with Iris Author: Daniel Duggan & Sarah Roberts - Faulkes Telescope Project Introduction Photometry is the measurement of the intensity or brightness of an astronomical object, such as a star or galaxy by adding

More information

High Time Resolution Photometry of V458 Vul

High Time Resolution Photometry of V458 Vul High Time Resolution Photometry of V458 Vul Samia Bouzid 2010 NSF/REU Program Physics Department, University of Notre Dame Advisor: Dr. Peter Garnavich High Time-Resolution Photometry of Nova V458 Vul

More information

Detection of Exoplanets by Amateur Astronomers

Detection of Exoplanets by Amateur Astronomers Detection of Exoplanets by Amateur Astronomers September 17, 2015 by Dennis M. Conti email: dennis_conti@hotmail.com 1 Background Exoplanet (Extrasolar Planet) a planet orbiting a distant host star First

More information

Exoplanet Observing by Amateur Astronomers

Exoplanet Observing by Amateur Astronomers Exoplanet Observing by Amateur Astronomers May 22, 2016 by Dennis M. Conti, Ph.D. Chairman, AAVSO Exoplanet Section email: dennis@astrodennis.com 1 The Night Sky Q: Which stars host one or more planets?

More information

Lecture 9. November 1, 2018 Lab 5 Analysis

Lecture 9. November 1, 2018 Lab 5 Analysis Lecture 9 November 1, 2018 Lab 5 Analysis News Lab 2 Handed back with solution; mean: 92.1, std dev: 5.5 Lab 3 Handed back next week (I hope). Lab 4 Due November 1 (today) News Lab 5 (Transiting Exoplanets)

More information

Exoplanet Observations by Amateur Astronomers. by Dennis M. Conti, Ph.D. Chairman, AAVSO Exoplanet Section

Exoplanet Observations by Amateur Astronomers. by Dennis M. Conti, Ph.D. Chairman, AAVSO Exoplanet Section Exoplanet Observations by Amateur Astronomers by Dennis M. Conti, Ph.D. Chairman, AAVSO Exoplanet Section email: dennis@astrodennis.com 1 The Night Sky Q: Which stars host one or more planets? A: Most

More information

Precise photometric timming of transiting exoplanets

Precise photometric timming of transiting exoplanets Precise photometric timming of transiting exoplanets Proposal for the spanish network of robotic telescopes Guillem Anglada-Escudé anglada@am.ub.es... Departament d Astronomia i Meteorologia, Universitat

More information

Fundamentals of Exoplanet Observing

Fundamentals of Exoplanet Observing Fundamentals of Exoplanet Observing Dennis M. Conti Chair, AAVSO Exoplanet Section Copyright Dennis M. Conti 2017 1 The Strange World of Exoplanets Most exoplanets we have discovered are close-in, large

More information

Fundamentals of Exoplanet Observing

Fundamentals of Exoplanet Observing Fundamentals of Exoplanet Observing Dennis M. Conti Chair, AAVSO Exoplanet Section Copyright Dennis M. Conti 2017 1 The Strange World of Exoplanets Most exoplanets we have discovered are close-in, large

More information

Secondary Eclipse of Exoplanet TrES-1

Secondary Eclipse of Exoplanet TrES-1 Secondary Eclipse of Exoplanet TrES-1 Patrick Herfst Studentnumber 9906770 Sterrewacht Leiden, room 441 herfst@strw.leidenuniv.nl Supervised by dr. Ignas Snellen Contents 1 Summary 3 2 Introduction 4 2.1

More information

Data Processing in DES

Data Processing in DES Data Processing in DES Brian Yanny Oct 28, 2016 http://data.darkenergysurvey.org/fnalmisc/talk/detrend.p Basic Signal-to-Noise calculation in astronomy: Assuming a perfect atmosphere (fixed PSF of p arcsec

More information

ADVANCED CCD PHOTOMETRY AND EXOPLANET TRANSIT PHOTOMETRY. By : Kenny A. Diaz Eguigure

ADVANCED CCD PHOTOMETRY AND EXOPLANET TRANSIT PHOTOMETRY. By : Kenny A. Diaz Eguigure ADVANCED CCD PHOTOMETRY AND EXOPLANET TRANSIT PHOTOMETRY By : Kenny A. Diaz Eguigure KELT: THE KILODEGREE EXTREMELY LITTLE TELESCOPE Robotic Survey for Transiting Exoplanets KELT-North Deployed 2005 to

More information

Observer Anomaly(?): Recent Jitter and PSF Variations

Observer Anomaly(?): Recent Jitter and PSF Variations Instrument Science Report TEL 2005-01 Observer Anomaly(?): Recent Jitter and PSF Variations R. L. Gilliland gillil@stsci.edu February 2005 Abstract An anomaly in the HST Pointing Control System (PCS) has

More information

Expected precision on planet radii with

Expected precision on planet radii with Expected precision on planet radii with Adrien Deline 1, Didier Queloz 1,2 1 University of Geneva 2 University of Cambridge 24 th 26 th July 2017 CHEOPS Science Workshop 5 Schloss Seggau, Austria Field

More information

Currently, the largest optical telescope mirrors have a diameter of A) 1 m. B) 2 m. C) 5 m. D) 10 m. E) 100 m.

Currently, the largest optical telescope mirrors have a diameter of A) 1 m. B) 2 m. C) 5 m. D) 10 m. E) 100 m. If a material is highly opaque, then it reflects most light. absorbs most light. transmits most light. scatters most light. emits most light. When light reflects off an object, what is the relation between

More information

HD Transits HST/STIS First Transiting Exo-Planet. Exoplanet Discovery Methods. Paper Due Tue, Feb 23. (4) Transits. Transits.

HD 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 information

Determining the Orbital Period of the Cataclysmic Variable CSS1204 Using Data from the Vatican Advanced Technology Telescope

Determining the Orbital Period of the Cataclysmic Variable CSS1204 Using Data from the Vatican Advanced Technology Telescope Determining the Orbital Period of the Cataclysmic Variable CSS1204 Using Data from the Vatican Advanced Technology Telescope Amy Applegate 2012 NSF/REU Program Physics Department, University of Notre Dame

More information

9.1 Years of All-Sky Hard X-ray Monitoring with BATSE

9.1 Years of All-Sky Hard X-ray Monitoring with BATSE 9.1 Years of All-Sky Hard X-ray Monitoring with CGRO BATSE Large Area Detector (LAD) BATSE 1 of 8 BATSE Colleen A. Wilson (NASA/MSFC), for the BATSE teams at MSFC and Southampton Abstract The hard X-ray

More information

NICMOS Status and Plans

NICMOS Status and Plans 1997 HST Calibration Workshop Space Telescope Science Institute, 1997 S. Casertano, et al., eds. NICMOS Status and Plans Rodger I. Thompson Steward Observatory, University of Arizona, Tucson, AZ 85721

More information

Astrometric Performance of STIS CCD CTI Corrections on Omega Cen Images

Astrometric Performance of STIS CCD CTI Corrections on Omega Cen Images Instrument Science Report STIS 2015-05 Astrometric Performance of STIS CCD CTI Corrections on Omega Cen Images John Biretta, Sean Lockwood, and John Debes September 28, 2015 ABSTRACT We are in the process

More information

Photometry and Transit-Timing Analysis for Eleven Transiting Exoplanets. Katherine Rebecca de Kleer

Photometry and Transit-Timing Analysis for Eleven Transiting Exoplanets. Katherine Rebecca de Kleer Photometry and Transit-Timing Analysis for Eleven Transiting Exoplanets by Katherine Rebecca de Kleer Submitted to the Department of Physics in partial fulfillment of the requirements for the degree of

More information

Analyzing Spiral Galaxies Observed in Near-Infrared

Analyzing Spiral Galaxies Observed in Near-Infrared Analyzing Spiral Galaxies Observed in Near-Infrared Preben Grosbøl European Southern Observatory Karl-Schwarzschild-Str. 2, D-85748 Garching, Germany Abstract A sample of 54 spiral galaxies was observed

More information

Amateur Astronomer Participation in the TESS Exoplanet Mission

Amateur Astronomer Participation in the TESS Exoplanet Mission Amateur Astronomer Participation in the TESS Exoplanet Mission Dennis M. Conti Chair, AAVSO Exoplanet Section Member, TESS Follow-up Observing Program Copyright Dennis M. Conti 2018 1 The Big Picture Is

More information

Photometric Techniques II Data analysis, errors, completeness

Photometric Techniques II Data analysis, errors, completeness Photometric Techniques II Data analysis, errors, completeness Sergio Ortolani Dipartimento di Astronomia Universita di Padova, Italy. The fitting technique assumes the linearity of the intensity values

More information

Theoretical Examination

Theoretical Examination Page 1 of (T1) True or False Determine if each of the following statements is True or False. In the Summary Answersheet, tick the correct answer (TRUE / FALSE) for each statement. No justifications are

More information

IMPROVING THE DECONVOLUTION METHOD FOR ASTEROID IMAGES: OBSERVING 511 DAVIDA, 52 EUROPA, AND 12 VICTORIA

IMPROVING THE DECONVOLUTION METHOD FOR ASTEROID IMAGES: OBSERVING 511 DAVIDA, 52 EUROPA, AND 12 VICTORIA IMPROVING THE DECONVOLUTION METHOD FOR ASTEROID IMAGES: OBSERVING 511 DAVIDA, 52 EUROPA, AND 12 VICTORIA Z Robert Knight Department of Physics and Astronomy University of Hawai`i at Hilo ABSTRACT Deconvolution

More information

VRI Photometry of M67 for CCD Standardization at 2.3m VBT

VRI Photometry of M67 for CCD Standardization at 2.3m VBT J. Astrophys. Astr. (1992) 13, 293 305 VRI Photometry of M67 for CCD Standardization at 2.3m VBT P. N. Bhat & K. P. Singh Tata Institute of Fundamental Research, Bombay 400 005 T. P. Prabhu Indian Institute

More information

AstroBITS: Open Cluster Project

AstroBITS: Open Cluster Project AstroBITS: Open Cluster Project I. Introduction The observational data that astronomers have gathered over many years indicate that all stars form in clusters. In a cloud of hydrogen gas, laced with helium

More information

Open Cluster Photometry: Part II

Open Cluster Photometry: Part II Project 4 Open Cluster Photometry: Part II Observational Astronomy ASTR 310 Fall 2005 1 Introduction The objective of this and the previous project is to learn how to produce color-magnitude diagrams of

More information

High Precision Exoplanet Observations with Amateur Telescopes

High Precision Exoplanet Observations with Amateur Telescopes High Precision Exoplanet Observations with Amateur Telescopes Dennis M. Conti Chair, AAVSO Exoplanet Section Member, KELT Follow-up Team Member, TESS TFOP Working Group HAL Meeting: October 19, 2017 1

More information

Exoplanet Transits: Light Curve Photometry

Exoplanet Transits: Light Curve Photometry > REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < 1 Exoplanet Transits: Light Curve Photometry Lydia Shannon Center for Astrophysics, Space Physics and Engineering

More information

Lecture #15: Plan. Telescopes (cont d) Effects of Earth s Atmosphere Extrasolar planets = Exoplanets

Lecture #15: Plan. Telescopes (cont d) Effects of Earth s Atmosphere Extrasolar planets = Exoplanets Lecture #15: Plan Telescopes (cont d) Effects of Earth s Atmosphere Extrasolar planets = Exoplanets Resolving Power (review) The bigger the size of the telescope, the better it is at discerning fine details

More information

Basics of Photometry

Basics of Photometry Basics of Photometry Photometry: Basic Questions How do you identify objects in your image? How do you measure the flux from an object? What are the potential challenges? Does it matter what type of object

More information

Analysis of wavelength shifts reported for X-shooter spectra

Analysis of wavelength shifts reported for X-shooter spectra Analysis of wavelength shifts reported for X-shooter spectra S. Moehler (SDP) June 15, 2015 Executive Summary I investigated the causes for wavelength offsets seen in telluric lines and sky lines of extracted

More information

1. Give short answers to the following questions. a. What limits the size of a corrected field of view in AO?

1. Give short answers to the following questions. a. What limits the size of a corrected field of view in AO? Astronomy 418/518 final practice exam 1. Give short answers to the following questions. a. What limits the size of a corrected field of view in AO? b. Describe the visibility vs. baseline for a two element,

More information

The WFC3 IR Blobs Monitoring

The WFC3 IR Blobs Monitoring The WFC3 IR Blobs Monitoring N. Pirzkal, B. Hilbert Nov 13, 2012 ABSTRACT We present new results on the WFC3 IR Blobs based on analysis of data acquired using the WFC3 IR channel from 2010 to 2012. In

More information

The shapes of faint galaxies: A window unto mass in the universe

The shapes of faint galaxies: A window unto mass in the universe Lecture 15 The shapes of faint galaxies: A window unto mass in the universe Intensity weighted second moments Optimal filtering Weak gravitational lensing Shear components Shear detection Inverse problem:

More information

arxiv: v1 [astro-ph.ep] 13 Jan 2009

arxiv: v1 [astro-ph.ep] 13 Jan 2009 Astronomy & Astrophysics manuscript no. 1239 c ESO 2013 June 9, 2013 Letter to the Editor Ground-based K-band detection of thermal emission from the exoplanet TrES-3b E.J.W. de Mooij 1 and I.A.G. Snellen

More information

C. Watson, E. Churchwell, R. Indebetouw, M. Meade, B. Babler, B. Whitney

C. Watson, E. Churchwell, R. Indebetouw, M. Meade, B. Babler, B. Whitney Reliability and Completeness for the GLIMPSE Survey C. Watson, E. Churchwell, R. Indebetouw, M. Meade, B. Babler, B. Whitney Abstract This document examines the GLIMPSE observing strategy and criteria

More information

Astrometry (STEP) M. Shao

Astrometry (STEP) M. Shao Technical Issues for Narrow Angle Astrometry (STEP) M. Shao Outline Ground based narrow angle astrometry Current state of the art (0.5~1 mas (in 30 min) What are the limiting error sources Photon noise

More information

Searching for Earth-Like Planets:

Searching for Earth-Like Planets: Searching for Earth-Like Planets: NASA s Terrestrial Planet Finder Space Telescope Robert J. Vanderbei January 11, 2004 Amateur Astronomers Association of Princeton Peyton Hall, Princeton University Page

More information

Exoplanet False Positive Detection with Sub-meter Telescopes

Exoplanet False Positive Detection with Sub-meter Telescopes Exoplanet False Positive Detection with Sub-meter Telescopes Dennis M. Conti Chair, AAVSO Exoplanet Section Member, TESS Follow-up Observing Program Copyright Dennis M. Conti 2018 1 Topics What are typical

More information

OPTICAL PHOTOMETRY. Observational Astronomy (2011) 1

OPTICAL PHOTOMETRY. Observational Astronomy (2011) 1 OPTICAL PHOTOMETRY Observational Astronomy (2011) 1 The optical photons coming from an astronomical object (star, galaxy, quasar, etc) can be registered in the pixels of a frame (or image). Using a ground-based

More information

WHAT PHOTOMETRIC PRECISION CAN I ACHIEVE? DAVID BOYD

WHAT PHOTOMETRIC PRECISION CAN I ACHIEVE? DAVID BOYD WHAT PHOTOMETRIC PRECISION CAN I ACHIEVE? DAVID BOYD If you start using a CCD camera to carry out photometry on variable stars, this is a question that sooner or later you will ask yourself. Prompted by

More information

SUPPLEMENTARY INFORMATION

SUPPLEMENTARY INFORMATION doi:.38/nature149 1 Observation information This study examines 2 hours of data obtained between :33:42 and 12:46:28 Universal Time (UT) on April 17 11 using the -metre Keck telescope. This dataset was

More information

Impacts of focus on aspects of STIS UV Spectroscopy

Impacts of focus on aspects of STIS UV Spectroscopy Instrument Science Report STIS 2018-06 Impacts of focus on aspects of STIS UV Spectroscopy Allyssa Riley 1, TalaWanda Monroe 1, & Sean Lockwood 1 1 Space Telescope Science Institute, Baltimore, MD November

More information

Improving Precision in Exoplanet Transit Detection. Aimée Hall Institute of Astronomy, Cambridge Supervisor: Simon Hodgkin

Improving Precision in Exoplanet Transit Detection. Aimée Hall Institute of Astronomy, Cambridge Supervisor: Simon Hodgkin Improving Precision in Exoplanet Transit Detection Supervisor: Simon Hodgkin SuperWASP Two observatories: SuperWASP-North (Roque de los Muchachos, La Palma) SuperWASP-South (South African Astronomical

More information

First Results from BOKS: Searching for extra-solar planets in the Kepler Field

First Results from BOKS: Searching for extra-solar planets in the Kepler Field First Results from BOKS: Searching for extra-solar planets in the Kepler Field John Feldmeier Youngstown State University The BOKS TEAM PIs: John Feldmeier (YSU), Steve Howell (NOAO/WIYN) Co-Is: Mandy

More information

Optical Photometry of Dwarf Nova QZ Serpentis in Quiescence

Optical Photometry of Dwarf Nova QZ Serpentis in Quiescence Optical Photometry of Dwarf Nova QZ Serpentis in Quiescence Erica D. Jones Center for Astrophysics, Space Physics and Engineering Research at Baylor University Dr. Dwight Russell Department of Physics

More information

PROJECT GLOBULAR CLUSTERS

PROJECT GLOBULAR CLUSTERS PROJECT 5 GLOBULAR CLUSTERS Objective: The objective of this exercise is the calculation of the core and tidal radius of a globular cluster in the Milky Way. Measure the tidal radius of a globular cluster

More information

Amateur Astronomer Participation in the TESS Exoplanet Mission

Amateur Astronomer Participation in the TESS Exoplanet Mission Amateur Astronomer Participation in the TESS Exoplanet Mission Dennis M. Conti Chair, AAVSO Exoplanet Section Member, TESS Follow-up Observing Program Copyright Dennis M. Conti 2018 1 Copyright Dennis

More information

High Signal-to-Noise, Differential NICMOS Spectrophotometry

High Signal-to-Noise, Differential NICMOS Spectrophotometry Instrument Science Report NICMOS 2003-001 High Signal-to-Noise, Differential NICMOS Spectrophotometry R.L. Gilliland, S. Arribas January 7, 2003 ABSTRACT We report analysis for NICMOS CAL/9642, High S/N

More information

Lecture #15: Plan. Telescopes (cont d) Effects of Earth s Atmosphere Extrasolar planets = Exoplanets

Lecture #15: Plan. Telescopes (cont d) Effects of Earth s Atmosphere Extrasolar planets = Exoplanets Lecture #15: Plan Telescopes (cont d) Effects of Earth s Atmosphere Extrasolar planets = Exoplanets Collecting Area Light bucket : the bigger the area of the telescope s mirror or lens, the more photons

More information

Photometric Products. Robert Lupton, Princeton University LSST Pipeline/Calibration Scientist PST/SAC PST/SAC,

Photometric Products. Robert Lupton, Princeton University LSST Pipeline/Calibration Scientist PST/SAC PST/SAC, Photometric Products Robert Lupton, Princeton University LSST Pipeline/Calibration Scientist PST/SAC 2018-02-27 PST/SAC, 2018-02-27 LSST2017 Tucson, AZ August 14-18, 2017 1 Outline Photometry Point Sources

More information

CLEA/VIREO PHOTOMETRY OF THE PLEIADES

CLEA/VIREO PHOTOMETRY OF THE PLEIADES CLEA/VIREO PHOTOMETRY OF THE PLEIADES Starting up the program The computer program you will use is a realistic simulation of a UBV photometer attached to a small (diameter=0.4 meters) research telescope.

More information

1 The Preliminary Processing

1 The Preliminary Processing AY 257 Modern Observational Techniques...23 1 The Preliminary Processing Frames must be corrected for a bias level and quantum efficiency variations on all scales. For a minority of CCDs and most near-ir

More information

AS750 Observational Astronomy

AS750 Observational Astronomy Lecture 9 0) Poisson! (quantum limitation) 1) Diffraction limit 2) Detection (aperture) limit a)simple case b)more realistic case 3) Atmosphere 2) Aperture limit (More realistic case) Aperture has m pixels

More information

Midterm Observing Project: RR Lyrae, Rapidly Pulsating Stars

Midterm Observing Project: RR Lyrae, Rapidly Pulsating Stars AY 145: Topics in Astrophysics Spring, 2005 Midterm Observing Project: RR Lyrae, Rapidly Pulsating Stars Observations: March 21-24, 2005 Lab Report Due: Friday April 15, 2005 Purpose: In place of a midterm

More information

A Fast Algorithm for Cosmic Rays Removal from Single Images

A Fast Algorithm for Cosmic Rays Removal from Single Images A Fast Algorithm for Cosmic Rays Removal from Single Images Wojtek Pych David Dunlap Observatory, University of Toronto P.O. Box 360, Richmond Hill, Ontario, Canada L4C 4Y6 and Copernicus Astronomical

More information

Lab 7: The H-R Diagram of an Open Cluster

Lab 7: The H-R Diagram of an Open Cluster Lab 7: The H-R Diagram of an Open Cluster Due Date: 2007 Nov 27 (after thanksgiving) 1 Introduction: The HR Diagram In this two week project you will do absolute (not differential) photometry with a CCD

More information

Monitoring The HRC-S UV Rate: Observations of Vega

Monitoring The HRC-S UV Rate: Observations of Vega Monitoring The HRC-S UV Rate: Observations of Vega Deron Pease, Vinay Kashyap, Jeremy Drake and Michael Juda 10 May 2005 Abstract We present an interim report on Chandra HRC-S calibration observations

More information

Dreaming of the future: The 2004 Venus transit

Dreaming of the future: The 2004 Venus transit 6 Dreaming of the future: The 2004 Venus transit For the first time ever, the Venus 2004 transit provided the opportunity to test the technique called Transit Spectroscopy, in a planet whose atmosphere

More information

arxiv:astro-ph/ v1 12 Nov 2003

arxiv:astro-ph/ v1 12 Nov 2003 A Fast Algorithm for Cosmic Rays Removal from Single Images Wojtek Pych arxiv:astro-ph/0311290v1 12 Nov 2003 David Dunlap Observatory, University of Toronto P.O. Box 360, Richmond Hill, Ontario, Canada

More information

Early-Science call for observing time with SAM-FP

Early-Science call for observing time with SAM-FP Early-Science call for observing time with SAM-FP 1. General description SOAR is opening a call for proposals for early-science with SAM-FP in 2016B, for 4 nights (September 29 October 2, 2016). SAM-FP

More information

arxiv: v2 [astro-ph.ep] 2 Nov 2017

arxiv: v2 [astro-ph.ep] 2 Nov 2017 Palomar Optical Spectrum of Hyperbolic Near-Earth Object A/2017 U1 Joseph R. Masiero 1 ABSTRACT arxiv:1710.09977v2 [astro-ph.ep] 2 Nov 2017 We present optical spectroscopy of the recently discovered hyperbolic

More information

Color-Magnitude Diagram Lab Manual

Color-Magnitude Diagram Lab Manual Color-Magnitude Diagram Lab Manual Due Oct. 21, 2011 1 Pre-Lab 1.1 Photometry and the Magnitude Scale The brightness of stars is represented by its value on the magnitude scale. The ancient Greek astronomer

More information

Modeling the CCD Undersampling Effect in the BATC Photometric System

Modeling the CCD Undersampling Effect in the BATC Photometric System Publications of the Astronomical Society of the Pacific, 117:86 93, 2005 January 2004. The Astronomical Society of the Pacific. All rights reserved. Printed in U.S.A. Modeling the CCD Undersampling Effect

More information

Simulations for H.E.S.S.

Simulations for H.E.S.S. Simulations for H.E.S.S. by K. Bernlöhr MPIK Heidelberg & HU Berlin Air shower measurement methods Imaging atmospheric Cherenkov telescopes In the imaging atmospheric Cherenkov telescope (IACT) technique,

More information

Keck Adaptive Optics Note #385. Feasibility of LGS AO observations in the vicinity of Jupiter. Stephan Kellner and Marcos van Dam

Keck Adaptive Optics Note #385. Feasibility of LGS AO observations in the vicinity of Jupiter. Stephan Kellner and Marcos van Dam Keck Adaptive Optics Note #385 Feasibility of LGS AO observations in the vicinity of Jupiter Stephan Kellner and Marcos van Dam Version 2: 25 July 2006 1 Introduction It has been proposed by Imke De Pater

More information

Point Spread Functions. Aperture Photometry. Obs Tech Obs Tech 26 Sep 2017

Point Spread Functions. Aperture Photometry. Obs Tech Obs Tech 26 Sep 2017 Point Spread Functions & Aperture Photometry Obs Tech Obs Tech 26 Sep 2017 Point Spread Functions (PSFs) Stars are far away (typically d >> 3x10 15 km) Stars are relatively small (D ~ 10 6 km) Angular

More information

Data Reduction - Optical / NIR Imaging. Chian-Chou Chen Ph319

Data Reduction - Optical / NIR Imaging. Chian-Chou Chen Ph319 Data Reduction - Optical / NIR Imaging Chian-Chou Chen (T.C.) @ Ph319 Images at different wavelengths... Images at different wavelengths... However, the raw data are always not as pretty Why? The total

More information

A Comparison Between a Non-Linear and a Linear Gaussian Statistical Detector for Detecting Dim Satellites

A Comparison Between a Non-Linear and a Linear Gaussian Statistical Detector for Detecting Dim Satellites A Comparison Between a on-linear and a Linear Gaussian Statistical Detector for Detecting Dim Satellites Lt Stephen Maksim United States Air Force Maj J. Chris Zingarelli United States Air Force Dr. Stephen

More information

SBC FLATS: PRISM P-FLATS and IMAGING L-FLATS

SBC FLATS: PRISM P-FLATS and IMAGING L-FLATS Instrument Science Report ACS 2006-08 SBC FLATS: PRISM P-FLATS and IMAGING L-FLATS R. C. Bohlin & J. Mack December 2006 ABSTRACT The internal deuterium lamp was used to illuminate the SBC detector through

More information

Lab 1: Introduction to the sky and making telescopic observations with the CCD camera. AST 152M Lab Instructor: Greg Doppmann Due: Feb 11, 2000

Lab 1: Introduction to the sky and making telescopic observations with the CCD camera. AST 152M Lab Instructor: Greg Doppmann Due: Feb 11, 2000 Lab 1: Introduction to the sky and making telescopic observations with the CCD camera. AST 152M Lab Instructor: Greg Doppmann Due: Feb 11, 2000 Objective: The goal of this lab is to give students their

More information

Telescopes. Optical Telescope Design. Reflecting Telescope

Telescopes. Optical Telescope Design. Reflecting Telescope Telescopes The science of astronomy was revolutionized after the invention of the telescope in the early 17th century Telescopes and detectors have been constantly improved over time in order to look at

More information

Impressions: First Light Images from UVIT in Orbit

Impressions: First Light Images from UVIT in Orbit Impressions: First Light Images from UVIT in Orbit Drafted by S N Tandon on behalf of UVIT team. December 4, 2015; V1.0 1. Introduction: Ultraviolet Imaging Telescope (UVIT) is the long wavelength eye

More information

optical / IR: photon counting flux density or magnitude corresponds to number of electrons per second (mean rate)

optical / IR: photon counting flux density or magnitude corresponds to number of electrons per second (mean rate) optical / IR: photon counting flux density or magnitude corresponds to number of electrons per second (mean rate) N electrons/sec = ɛ F λ λa hc/λ 0 efficiency factor flux density x bandpass x collecting

More information

EXPOSURE TIME ESTIMATION

EXPOSURE TIME ESTIMATION ASTR 511/O Connell Lec 12 1 EXPOSURE TIME ESTIMATION An essential part of planning any observation is to estimate the total exposure time needed to satisfy your scientific goal. General considerations

More information

ORE Open Research Exeter

ORE Open Research Exeter ORE Open Research Exeter TITLE A Spitzer search for water in the transiting exoplanet HD 189733b AUTHORS Ehrenreich, D.; Hebrard, G.; Lecavelier des Etangs, A.; et al. JOURNAL Astrophysical Journal DEPOSITED

More information

Cross-Talk in the ACS WFC Detectors. I: Description of the Effect

Cross-Talk in the ACS WFC Detectors. I: Description of the Effect Cross-Talk in the ACS WFC Detectors. I: Description of the Effect Mauro Giavalisco August 10, 2004 ABSTRACT Images acquired with the Wide Field Channel (WFC) of the Advanced Camera for Surveys (ACS) are

More information

An Adaptive Autoguider using a Starlight Xpress SX Camera S. B. Foulkes, Westward, Ashperton, Nr. Ledbury, HR8 2RY. Abstract

An Adaptive Autoguider using a Starlight Xpress SX Camera S. B. Foulkes, Westward, Ashperton, Nr. Ledbury, HR8 2RY. Abstract An Adaptive Autoguider using a Starlight Xpress SX Camera S. B. Foulkes, Westward, Ashperton, Nr. Ledbury, HR8 2RY. Abstract The acquisition of very faint deep sky objects, be it analog with film or digital

More information

Reduction procedure of long-slit optical spectra. Astrophysical observatory of Asiago

Reduction procedure of long-slit optical spectra. Astrophysical observatory of Asiago Reduction procedure of long-slit optical spectra Astrophysical observatory of Asiago Spectrograph: slit + dispersion grating + detector (CCD) It produces two-dimension data: Spatial direction (x) along

More information

The Impact of x-cte in the WFC3/UVIS detector on Astrometry

The Impact of x-cte in the WFC3/UVIS detector on Astrometry Instrument Science Report WFC3 2014-02 The Impact of x-cte in the WFC3/UVIS detector on Astrometry Jay Anderson April 4, 2014 ABSTRACT Recent observations of the center of globular cluster Omega Centauri

More information

Breathing, Position Drift, and PSF Variations on the UVIS Detector

Breathing, Position Drift, and PSF Variations on the UVIS Detector SPACE TELESCOPE SCIENCE INSTITUTE Operated for NASA by AURA Instrument Science Report WFC3 1-1 Breathing, Position Drift, and PSF Variations on the UVIS Detector L. Dressel July 13, 1 ABSTRACT This study

More information

Chapter 3 Observational Program: Phase I The first phase of the observing program was begun in 1996 by Prof. Janes, prior to the Lowell Observatory pa

Chapter 3 Observational Program: Phase I The first phase of the observing program was begun in 1996 by Prof. Janes, prior to the Lowell Observatory pa Chapter 3 Observational Program: Phase I The first phase of the observing program was begun in 1996 by Prof. Janes, prior to the Lowell Observatory partnership that allowed Boston University access to

More information

Fringe Correction for STIS Near-IR Long-Slit Spectra using Contemporaneous Tungsten Flat Fields

Fringe Correction for STIS Near-IR Long-Slit Spectra using Contemporaneous Tungsten Flat Fields 1997 HST Calibration Workshop Space Telescope Science Institute, 1997 S. Casertano, et al., eds. Fringe Correction for STIS Near-IR Long-Slit Spectra using Contemporaneous Tungsten Flat Fields Paul Goudfrooij

More information

F = ma P 2 = a 3 (M + m) P 2 = a 3. max T = 2900 K m

F = ma P 2 = a 3 (M + m) P 2 = a 3. max T = 2900 K m Summer 2013 Astronomy - Test 1 Test form A Name Do not forget to write your name and fill in the bubbles with your student number, and fill in test form A on the answer sheet. Write your name above as

More information

IDENTIFICATION AND PHOTOMETRY OF CANDIDATE TRANSITING EXOPLANET SIGNALS

IDENTIFICATION AND PHOTOMETRY OF CANDIDATE TRANSITING EXOPLANET SIGNALS IDENTIFICATION AND PHOTOMETRY OF CANDIDATE TRANSITING EXOPLANET SIGNALS Emily K. Chang School of Ocean and Earth Science and Technology University of Hawai i at Mānoa Honolulu, HI 96822 ABSTRACT Exoplanet

More information

GALEX GR1 Instrument Performance and Calibration Review

GALEX GR1 Instrument Performance and Calibration Review GALEX GR1 Instrument Performance and Calibration Review Patrick Morrissey Caltech Operations Overview GALEX is operating quite smoothly in 2004. Active space weather has mostly dissipated. FUV is shut

More information

arxiv: v1 [astro-ph.im] 31 Jul 2014

arxiv: v1 [astro-ph.im] 31 Jul 2014 The nonlinear photon transfer curve of CCDs and its effects on photometry arxiv:1407.880v1 [astro-ph.im] 31 Jul 014 Bin Ma 1, Zhaohui Shang,1, Lifan Wang 3,4, Yi Hu 1, Qiang Liu 1, Peng Wei 1 1 National

More information

Exploring Data. Keck LRIS spectra. Handbook of CCD Astronomy by Steve Howell Chap. 4, parts of 6

Exploring Data. Keck LRIS spectra. Handbook of CCD Astronomy by Steve Howell Chap. 4, parts of 6 Exploring Data Keck LRIS spectra Handbook of CCD Astronomy by Steve Howell Chap. 4, parts of 6 FITS: Flexible Image Transport System Digital file format used to store astronomical images, data, and catalogs.

More information

Earth Flats. 1. Introduction. Instrument Science Report ACS R. C. Bohlin, J. Mack, G. Hartig, & M. Sirianni October 25, 2005

Earth Flats. 1. Introduction. Instrument Science Report ACS R. C. Bohlin, J. Mack, G. Hartig, & M. Sirianni October 25, 2005 Instrument Science Report ACS 2005-12 Earth Flats R. C. Bohlin, J. Mack, G. Hartig, & M. Sirianni October 25, 2005 ABSTRACT Since the last ISR 2003-02 on the use of Earth observations for a source of flat

More information

Limits on Pluto Rings from the June Stellar Occultation. Henry Throop, R. G. French, K. Shoemaker, C. R. Ruhland, L. A. Young, C. B.

Limits on Pluto Rings from the June Stellar Occultation. Henry Throop, R. G. French, K. Shoemaker, C. R. Ruhland, L. A. Young, C. B. Limits on Pluto Rings from the June 12 2006 Stellar Occultation Henry Throop, R. G. French, K. Shoemaker, C. R. Ruhland, L. A. Young, C. B. Olkin Pluto System on The Eve of New Horizons - APL, July 2013

More information

APPLICATION NOTE. Filter Set Prescription Alan Holmes

APPLICATION NOTE. Filter Set Prescription Alan Holmes APPLICATION NOTE Filter Set Prescription Alan Holmes August 1st, 22 SBIG has a color filter set prescription specifically designed to achieve correctly balanced color images for galaxies and nebulae. Our

More information