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A&A 454, 527–536 (2006) Astronomy DOI: 10.1051/0004-6361:20053468 & c ESO 2006 Astrophysics A search for photometric variability of hydrogen-deficient planetary-nebula nuclei, J. M. González Pérez1,2, J.-E. Solheim2,3, and R. Kamben2 1 Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain e-mail: [email protected] 2 Institut of Physics, University of Tromsø, 9037 Tromsø, Norway 3 Institut of Theoretical Astrophysics, University of Oslo, PO box 1029 Blindern, 0315 Oslo, Norway Received 18 May 2005 / Accepted 9 March 2006 ABSTRACT Aims. We searched for photometric variability in a sample of hot, hydrogen-deficient planetary nebula nuclei (PNNi) with “PG 1159” or “O VI” spectral type, most of them embedded in a bipolar or elliptical planetary nebula envelope (PNe). These characteristics may indicate the presence of a hidden close companion and an evolution affected by episodes of interaction between them. Methods. We obtained time-series photometry from a sample of 11 candidates using the Nordic Optical Telescope (NOT) with the Andalucía Faint Object Spectrograph and Camera (ALFOSC), modified with our own control software to be able to observe in a high- speed multi-windowing mode. The data were reduced on-line with the real time photometry (RTP) code, which allowed us to detect periodic variable stars with small amplitudes from CCD data in real time. We studied the properties of the observed modulation fre- quencies to investigate their nature. Results. We report the first detection of low-amplitude pulsations in the PNNi VV 47, NGC 6852, and Jn 1. In addition, we investi- gated the photometric variability of NGC 246. -
Messier Objects
Messier Objects From the Stocker Astroscience Center at Florida International University Miami Florida The Messier Project Main contributors: • Daniel Puentes • Steven Revesz • Bobby Martinez Charles Messier • Gabriel Salazar • Riya Gandhi • Dr. James Webb – Director, Stocker Astroscience center • All images reduced and combined using MIRA image processing software. (Mirametrics) What are Messier Objects? • Messier objects are a list of astronomical sources compiled by Charles Messier, an 18th and early 19th century astronomer. He created a list of distracting objects to avoid while comet hunting. This list now contains over 110 objects, many of which are the most famous astronomical bodies known. The list contains planetary nebula, star clusters, and other galaxies. - Bobby Martinez The Telescope The telescope used to take these images is an Astronomical Consultants and Equipment (ACE) 24- inch (0.61-meter) Ritchey-Chretien reflecting telescope. It has a focal ratio of F6.2 and is supported on a structure independent of the building that houses it. It is equipped with a Finger Lakes 1kx1k CCD camera cooled to -30o C at the Cassegrain focus. It is equipped with dual filter wheels, the first containing UBVRI scientific filters and the second RGBL color filters. Messier 1 Found 6,500 light years away in the constellation of Taurus, the Crab Nebula (known as M1) is a supernova remnant. The original supernova that formed the crab nebula was observed by Chinese, Japanese and Arab astronomers in 1054 AD as an incredibly bright “Guest star” which was visible for over twenty-two months. The supernova that produced the Crab Nebula is thought to have been an evolved star roughly ten times more massive than the Sun. -
Winter Constellations
Winter Constellations *Orion *Canis Major *Monoceros *Canis Minor *Gemini *Auriga *Taurus *Eradinus *Lepus *Monoceros *Cancer *Lynx *Ursa Major *Ursa Minor *Draco *Camelopardalis *Cassiopeia *Cepheus *Andromeda *Perseus *Lacerta *Pegasus *Triangulum *Aries *Pisces *Cetus *Leo (rising) *Hydra (rising) *Canes Venatici (rising) Orion--Myth: Orion, the great hunter. In one myth, Orion boasted he would kill all the wild animals on the earth. But, the earth goddess Gaia, who was the protector of all animals, produced a gigantic scorpion, whose body was so heavily encased that Orion was unable to pierce through the armour, and was himself stung to death. His companion Artemis was greatly saddened and arranged for Orion to be immortalised among the stars. Scorpius, the scorpion, was placed on the opposite side of the sky so that Orion would never be hurt by it again. To this day, Orion is never seen in the sky at the same time as Scorpius. DSO’s ● ***M42 “Orion Nebula” (Neb) with Trapezium A stellar nursery where new stars are being born, perhaps a thousand stars. These are immense clouds of interstellar gas and dust collapse inward to form stars, mainly of ionized hydrogen which gives off the red glow so dominant, and also ionized greenish oxygen gas. The youngest stars may be less than 300,000 years old, even as young as 10,000 years old (compared to the Sun, 4.6 billion years old). 1300 ly. 1 ● *M43--(Neb) “De Marin’s Nebula” The star-forming “comma-shaped” region connected to the Orion Nebula. ● *M78--(Neb) Hard to see. A star-forming region connected to the Orion Nebula. -
Planetary Nebulae
Planetary Nebulae A planetary nebula is a kind of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from old red giant stars late in their lives. The term "planetary nebula" is a misnomer that originated in the 1780s with astronomer William Herschel because when viewed through his telescope, these objects appeared to him to resemble the rounded shapes of planets. Herschel's name for these objects was popularly adopted and has not been changed. They are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years. The mechanism for formation of most planetary nebulae is thought to be the following: at the end of the star's life, during the red giant phase, the outer layers of the star are expelled by strong stellar winds. Eventually, after most of the red giant's atmosphere is dissipated, the exposed hot, luminous core emits ultraviolet radiation to ionize the ejected outer layers of the star. Absorbed ultraviolet light energizes the shell of nebulous gas around the central star, appearing as a bright colored planetary nebula at several discrete visible wavelengths. Planetary nebulae may play a crucial role in the chemical evolution of the Milky Way, returning material to the interstellar medium from stars where elements, the products of nucleosynthesis (such as carbon, nitrogen, oxygen and neon), have been created. Planetary nebulae are also observed in more distant galaxies, yielding useful information about their chemical abundances. In recent years, Hubble Space Telescope images have revealed many planetary nebulae to have extremely complex and varied morphologies. -
Feb BACK BAY 2019
Feb BACK BAY 2019 The official newsletter of the Back Bay Amateur Astronomers CONTENTS COMING UP Gamma Burst 2 Feb 7 BBAA Meeting Eclipse Collage 3 7:30-9PM TCC, Virginia Beach NSN Article 6 Heart Nebula 7 Feb 8 Silent Sky Club meeting 10 10-11PM Little Theatre of VB Winter DSOs 11 Contact info 16 Feb 8 Cornwatch Photo by Chuck Jagow Canon 60Da, various exposures, iOptron mount with an Orion 80ED Calendar 17 dusk-dawn The best 9 out of 3465 images taken from about 10:00 PM on the 20th Cornland Park through 2:20 AM on the 21st. Unprocessed images (only cropped). Feb 14 Garden Stars 7-8:30PM LOOKING UP! a message from the president Norfolk Botanical Gardens This month’s most talked about astronomy event has to be the total lunar Feb 16 Saturday Sun-day eclipse. The BBAA participated by supporting the Watch Party at the 10AM-1PM Chesapeake Planetarium. Anyone in attendance will tell you it was COLD, but Elizabeth River Park manageable if you wore layers, utilized the planetarium where Dr. Robert Hitt seemed to have the thermostat set to 100 degrees, and drank copious amounts Feb 23 Skywatch of the hot coffee that Kent Blackwell brewed in the back office. 6PM-10PM The event had a huge following on Facebook but with the cold Northwest River Park temperatures, we weren’t sure how many would come out. By Kent’s estimate there were between 100–200 people in attendance. Many club members set up telescopes, as well as a few members of the public too. -
Astronomy Magazine Special Issue
γ ι ζ γ δ α κ β κ ε γ β ρ ε ζ υ α φ ψ ω χ α π χ φ γ ω ο ι δ κ α ξ υ λ τ μ β α σ θ ε β σ δ γ ψ λ ω σ η ν θ Aι must-have for all stargazers η δ μ NEW EDITION! ζ λ β ε η κ NGC 6664 NGC 6539 ε τ μ NGC 6712 α υ δ ζ M26 ν NGC 6649 ψ Struve 2325 ζ ξ ATLAS χ α NGC 6604 ξ ο ν ν SCUTUM M16 of the γ SERP β NGC 6605 γ V450 ξ η υ η NGC 6645 M17 φ θ M18 ζ ρ ρ1 π Barnard 92 ο χ σ M25 M24 STARS M23 ν β κ All-in-one introduction ALL NEW MAPS WITH: to the night sky 42,000 more stars (87,000 plotted down to magnitude 8.5) AND 150+ more deep-sky objects (more than 1,200 total) The Eagle Nebula (M16) combines a dark nebula and a star cluster. In 100+ this intense region of star formation, “pillars” form at the boundaries spectacular between hot and cold gas. You’ll find this object on Map 14, a celestial portion of which lies above. photos PLUS: How to observe star clusters, nebulae, and galaxies AS2-CV0610.indd 1 6/10/10 4:17 PM NEW EDITION! AtlAs Tour the night sky of the The staff of Astronomy magazine decided to This atlas presents produce its first star atlas in 2006. -
A Basic Requirement for Studying the Heavens Is Determining Where In
Abasic requirement for studying the heavens is determining where in the sky things are. To specify sky positions, astronomers have developed several coordinate systems. Each uses a coordinate grid projected on to the celestial sphere, in analogy to the geographic coordinate system used on the surface of the Earth. The coordinate systems differ only in their choice of the fundamental plane, which divides the sky into two equal hemispheres along a great circle (the fundamental plane of the geographic system is the Earth's equator) . Each coordinate system is named for its choice of fundamental plane. The equatorial coordinate system is probably the most widely used celestial coordinate system. It is also the one most closely related to the geographic coordinate system, because they use the same fun damental plane and the same poles. The projection of the Earth's equator onto the celestial sphere is called the celestial equator. Similarly, projecting the geographic poles on to the celest ial sphere defines the north and south celestial poles. However, there is an important difference between the equatorial and geographic coordinate systems: the geographic system is fixed to the Earth; it rotates as the Earth does . The equatorial system is fixed to the stars, so it appears to rotate across the sky with the stars, but of course it's really the Earth rotating under the fixed sky. The latitudinal (latitude-like) angle of the equatorial system is called declination (Dec for short) . It measures the angle of an object above or below the celestial equator. The longitud inal angle is called the right ascension (RA for short). -
Evolution of Star Clusters in Time-Variable Tidal Fields
Evolution of Star Clusters in Time-Variable Tidal Fields A Thesis Submitted to the Faculty of Drexel University by Ernest N. Mamikonyan in partial fulfillment of the requirement for the degree of Doctor of Philosophy December 12, 2013 Contents 1 Introduction 1 1.1 TypesofStarClusters............................ 2 1.1.1 GlobularClusters .......................... 3 1.1.2 OpenClusters............................ 4 1.2 Mass Function: From Young to Globular . 5 2 Arbitrary Tidal Acceleration 8 2.1 ApproximatingTidalEffects. 9 2.1.1 Tidal Acceleration Tensor . 10 2.2 Stellar Dynamics with KIRA ........................ 11 2.2.1 CircularOrbitinPoint-MassPotential . 14 2.3 GalaxyMergerSimulations . 16 2.3.1 TidalHistories............................ 19 2.4 N-BodySimulations ............................ 24 2.4.1 N-BodyUnits ............................ 26 2.4.2 Scaling ................................ 26 3 Mass Loss Model 30 i 3.1 Accelerated Two-Body Relaxation . 30 3.2 FluctuationsintheJacobiRadius. 34 3.3 Results .................................... 36 3.4 Discussion.................................. 37 3.4.1 Limitations ............................. 40 4 Globular Cluster Mass Functions 44 4.1 MassFunctionEvolution . 47 4.2 Results .................................... 48 4.2.1 SinkParticles ............................ 48 4.2.2 DiskParticles ............................ 50 4.2.3 HaloParticles ............................ 55 5 Conclusions and Future Work 57 Appendix A Implementation of Tidal Fields in KIRA 63 Appendix B Computing Tidal Acceleration from GADGET Output 66 ii List of Figures 1.1 Infrared image of the globular cluster Omega Centauri. It is the most massive cluster in the Galaxy and thought to be a remnant of a dwarf galaxy absorbed by the Milky Way. (NASA/JPL-Caltech/ NOAO/AURA/NSF)............................. 3 1.2 The Pleiades open cluster in the infrared. It is one of the most well- known and spectacular objects in the Galaxy. -
2018 Observatory Schedule
Astronomy Club of Akron 2018 Observatory Schedule 5031 Manchester Road, Akron, OH www.acaoh.org – The following events are open to the public. Please join us for stargazing and educational activities. Please arrive on time to avoid headlight distraction. – For notice of “impromptu star parties” not listed, send e-mail to [email protected] to request e-mail notification of unscheduled observing sessions. – Events will be cancelled if skies are cloudy. Always check website for star party status two hours before event. – This is an outdoor activity in an unheated environment. Nighttime temperatures drop rapidly, even during summer. A general rule of thumb is to dress for 15 degrees colder than predicted nighttime low temperature. – Please respect those who bring their own telescopes. Children should be supervised at all times. The observatory grounds is no place for toys or tomfoolery. – Please, no smoking on observatory grounds. Please, no use of cell phones or tablets in observatory (to preserve night vision). March 17 – 7:45pm July 7 – 9:00pm View the Great Orion Nebula & the beautiful star clusters of The Ring Nebula is a stunning sight in the 16” observatory Auriga through the 16” observatory telescope and view telescope; placed in the Milky Way, observers can see the Pleiades, Hyades, & Beehive Cluster through the 100mm nebula set in a field rich with stars. wide field telescope. Sky Tour: Winter Constellations July 14 – 8:45pm April 7 – 8:00pm Planet Night – Observe Venus at star party start. Jupiter and Special Event: Messier Marathon – stay all night to observe Saturn are well-placed during the observing session. -
Planetary Nebulae: Exposing the Top Polluters of the ISM
The Evolving ISM in the Milky Way & Nearby Galaxies Planetary Nebulae: Exposing the Top Polluters of the ISM Joseph L. Hora1, Massimo Marengo1, Howard A. Smith1, Luciano Cerrigone1, William B. Latter2 ABSTRACT The high mass loss rates of stars in their asymptotic giant branch (AGB) stage of evolution is one of the most important pathways for mass return from stars to the ISM. In the planetary nebulae (PNe) phase, the ejected material is illuminated and can be altered by the UV radiation from the central star. PNe therefore play a significant role in the ISM recycling process and in changing the environment around them. We show some highlights of the results of observations that have been carried out using the Spitzer instruments to study the gas and dust emission from PNe in the Milky Way and nearby galaxies. Spitzer is especially sensitive to the cool dust and molecules in the PNe shell and halos. We present new results from our program on Galactic PNe, including IRAC and IRS observations of NGC 6720 in the ring and halo of that nebula. Subject headings: galaxies: ISM | infrared: galaxies | infrared: ISM | ISM: dust, extinction | ISM: structure 1. Introduction A key link in the recycling of material to the Interstellar Medium (ISM) is the phase of stellar evolution from Asymptotic Giant Branch (AGB) to white dwarf star. When stars are on the AGB, they begin to lose mass at a prodigious rate. The stars on the AGB are relatively cool, and their atmospheres are a fertile environment for the formation of dust and molecules. -
The Young Open Cluster NGC 2129
Dartmouth College Dartmouth Digital Commons Dartmouth Scholarship Faculty Work 10-17-2006 The Young Open Cluster NGC 2129 Giovanni Carraro The University of Chile Brian Chaboyer Dartmouth College James Perencevich Dartmouth College Follow this and additional works at: https://digitalcommons.dartmouth.edu/facoa Part of the Astrophysics and Astronomy Commons Dartmouth Digital Commons Citation Carraro, Giovanni; Chaboyer, Brian; and Perencevich, James, "The Young Open Cluster NGC 2129" (2006). Dartmouth Scholarship. 1859. https://digitalcommons.dartmouth.edu/facoa/1859 This Article is brought to you for free and open access by the Faculty Work at Dartmouth Digital Commons. It has been accepted for inclusion in Dartmouth Scholarship by an authorized administrator of Dartmouth Digital Commons. For more information, please contact [email protected]. Mon. Not. R. Astron. Soc. 365, 867–873 (2006) doi:10.1111/j.1365-2966.2005.09762.x The young open cluster NGC 2129 , , Giovanni Carraro,1 2 3 Brian Chaboyer4 and James Perencevich4 1Departamento de Astronomia´ , Universidad de Chile, Casilla 36-D, Santiago, Chile 2Astronomy Department, Yale University, PO Box 208101, New Haven, CT 06520-8101, USA 3Dipartimento di Astronomia, Universitad` iPadova, Vicolo Osservatorio 2, I-35122 Padova, Italy 4Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755-3528, USA Accepted 2005 October 17. Received 2005 October 15; in original form 2005 June 7 ABSTRACT The first charge-coupled device UBV(RI)C photometric study in the area of the doubtful open cluster NGC 2129 is presented. Photometry of a field offset 15 arcmin northwards is also provided, to probe the Galactic disc population towards the cluster. -
Celebrating the Wonder of the Night Sky
Celebrating the Wonder of the Night Sky The heavens proclaim the glory of God. The skies display his craftsmanship. Psalm 19:1 NLT Celebrating the Wonder of the Night Sky Light Year Calculation: Simple! [Speed] 300 000 km/s [Time] x 60 s x 60 m x 24 h x 365.25 d [Distance] ≈ 10 000 000 000 000 km ≈ 63 000 AU Celebrating the Wonder of the Night Sky Milkyway Galaxy Hyades Star Cluster = 151 ly Barnard 68 Nebula = 400 ly Pleiades Star Cluster = 444 ly Coalsack Nebula = 600 ly Betelgeuse Star = 643 ly Helix Nebula = 700 ly Helix Nebula = 700 ly Witch Head Nebula = 900 ly Spirograph Nebula = 1 100 ly Orion Nebula = 1 344 ly Dumbbell Nebula = 1 360 ly Dumbbell Nebula = 1 360 ly Flame Nebula = 1 400 ly Flame Nebula = 1 400 ly Veil Nebula = 1 470 ly Horsehead Nebula = 1 500 ly Horsehead Nebula = 1 500 ly Sh2-106 Nebula = 2 000 ly Twin Jet Nebula = 2 100 ly Ring Nebula = 2 300 ly Ring Nebula = 2 300 ly NGC 2264 Nebula = 2 700 ly Cone Nebula = 2 700 ly Eskimo Nebula = 2 870 ly Sh2-71 Nebula = 3 200 ly Cat’s Eye Nebula = 3 300 ly Cat’s Eye Nebula = 3 300 ly IRAS 23166+1655 Nebula = 3 400 ly IRAS 23166+1655 Nebula = 3 400 ly Butterfly Nebula = 3 800 ly Lagoon Nebula = 4 100 ly Rotten Egg Nebula = 4 200 ly Trifid Nebula = 5 200 ly Monkey Head Nebula = 5 200 ly Lobster Nebula = 5 500 ly Pismis 24 Star Cluster = 5 500 ly Omega Nebula = 6 000 ly Crab Nebula = 6 500 ly RS Puppis Variable Star = 6 500 ly Eagle Nebula = 7 000 ly Eagle Nebula ‘Pillars of Creation’ = 7 000 ly SN1006 Supernova = 7 200 ly Red Spider Nebula = 8 000 ly Engraved Hourglass Nebula