DOCSLIB.ORG

An ASAS-SN Search for “Dipper” Stars in the Lupus Star-Forming Region

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
An ASAS-SN Search for “Dipper” Stars in the Lupus Star-Forming Region MNRAS 000,1{8 (2019) Preprint 27 July 2019 Compiled using MNRAS LATEX style file v3.0 Baby Boomers: An ASAS-SN Search for \Dipper" Stars in the Lupus Star-Forming Region J. W. Bredall,1 B. J. Shappee,1 T. Jayasinghe,2 E. J. Gaidos,3;4 K. Z. Stanek,2;5 C. S. Kochanek,2;4? J. L. Prieto,6;7 T. W. -S. Holoieny,8 Subo Dong,9 Todd A. Thompson,2;5;10 K. Hart,1 J. Gagn´e11 1Institute for Astronomy, University of Hawai`i at M¯anoa, 2680 Woodlawn Dr., Honolulu 96822, USA 2Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USA 3Department of Earth Sciences, University of Hawai`i at M¯anoa, Honolulu, HI 96822, USA 4Kavli Institute for Theoretical Physics, University of California at Santa Barbara, Santa Barbara, CA 93106, USA 5Center for Cosmology and Astroparticle Physics, The Ohio State University, 191 W. Woodruff Avenue, Columbus, OH 43210, USA 6N´ucleo de Astronom´ıade la Facultad de Ingenier´ıa y Ciencias, Universidad Diego Portales, Av. Ej´ercito 441, Santiago, Chile 7Millennium Institute of Astrophysics, Santiago, Chile 8Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101, USA 9Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Road 5, Hai Dian District, Beijing 100871, China 10Institute for Advanced Study, 1 Einstein Dr., Princeton, NJ 08540, USA 11Carnegie Institution of Washington DTM, 5241 Broad Branch Road NW, Washington, DC 20015, USA ABSTRACT Examining variable Young Stellar Objects (YSOs), especially \dipper" stars, gives us unique insight into stellar and planetary formation. While there have been several recent high-precision surveys of YSOs in specific star-forming regions, variability can be missed as a result of their short baselines and limited coverage. Here we present a YSO survey of the Lupus star forming region using the All-Sky Automated Survey for Supernovae (ASAS-SN). Despite being home to several well-studied variable YSOs, the Lupus clouds have currently no published cases of dipper stars. With ASAS-SN, we are able to search for variable YSOs in a previously unexplored parameter space. In this search, we have found eight new dippers in Lupus, and present our findings in the context of known dipper populations. Key words: stars: variables: T Tauri, Herbig Ae/Be 1 INTRODUCTION current telescopes (Hedges et al. 2018). Thus, variable YSOs offer us a unique view of stellar and planetary formation. Exoplanetary science has seen much progress in recent years thanks to surveys such as Kepler (Borucki 2016) and TESS Herbst et al.(1994) splits the variability of YSOs (Ricker et al. 2014); however, many of these findings have into three main groups: Types I, II, and III. Each type of made it difficult to reconcile the layout of our own solar variability gives us insight into the different mechanics of system with what we observe in other systems (e.g., Mor- stellar and planetary formation. dasini et al. 2015; Raymond et al. 2018). One of the biggest problems with current models is understanding the struc- Type I variability is characterized by regular, periodic ture of protoplanetary disks and their interactions with the changes in luminosity of up to 0.5 mag, and is caused by magnetic field of the central Young Stellar Object (YSO) the rotation of starspots (Herbst 2012). Measuring the (Morbidelli & Raymond 2016). Recent findings have demon- period and how it changes over time can inform us about strated that observations of variable YSOs allow us to probe the evolution of the system's angular momentum. Rotation is also an input parameter for stellar magnetodynamic inner (. 1 AU) regions of disks. While Kepler has found sev- eral planets within this region, this scale is not resolvable by models, which can constrain interactions between the disk and stellar magnetic field. Type II variability is characterized by eruptive brightening ? Radcliffe Fellow events. This is normally observed as flaring, caused by mag- y Carnegie Fellow netic reconnection events. A more extreme case of Type II © 2019 The Authors 2 Bredall et al. variability is FU Orionis Stars (FUors), which can brighten work, we use ASAS-SN to perform a detailed search for dip- as much as 1 or 2 mag. This is believed to be caused pers in the Lupus region. by an increase in accretion driven by the magnetic field The Lupus region comprises multiple clouds of low-mass of the star (Herbst Herbst). Observations of these events star formation near the Scorpius Centaurus OB association can inform us of how these flares might affect disk structure. (Comer´on 2008). Lupus 3 is home to many well-studied T Tauri stars such as RU Lup and EX Lup, the prototype Type III variables are characterized by either periodic or EXor variable. While there have been several recent studies aperiodic dimming. UX Orionis Stars (UXors) are a well- on disk structure (e.g., Ansdell et al. 2016b, 2018b) and ac- known example of this phenomenon, caused by occultations cretion (e.g., Nisini et al. 2018) in Lupus YSOs, there are of dust throughout the disk. However, another subset of no published dippers in the Lupus clouds as of the writing Type III variables has emerged in recent years, known as of this paper. We are thus motivated to use our search for \dippers". Typical dimming for dipper systems is on the dippers as an optical supplement to current spectroscopic, order of 10 − 50%, though in some cases can be up to 5 X-ray, and infrared surveys of the region. mag. Unlike UXors, dippers are believed to be caused by This paper is outlined as follows: Observations and data transiting dust from the inner disk region (Hedges et al. reduction are discussed in x2, and variability selection crite- 2018). Observations of these dippers inform us of inner-disk ria are defined in x3. We find eight dippers in Lupus, which geometry that has otherwise been unavailable to us. are presented and discussed in x4. There has been a large effort in recent years to observe star-forming regions and classify any variable YSOs therein, 2 OBSERVATIONS with special attention to dipper stars (e.g., Cody et al. 2014; While ASAS-SN has discovered variable YSOs in the past Ansdell et al. 2016a; Rodriguez et al. 2017; Ansdell et al. (e.g., Holoien et al. 2014; Sicilia-Aguilar, A. et al. 2017), 2018a; Cody & Hillenbrand 2018; Hedges et al. 2018). Many the automated data reduction pipeline is best equipped to of these surveys utilize high-cadence, high-precision space detect bright transients such as supernovae. Indeed, smaller- telescopes such as Spitzer (Fazio et al. 2004) or K2 (Howell scale variability detections are intentionally missed by the et al. 2014). These studies have allowed for high-sampling pipeline. Nevertheless, all data is archived and available for of individual transient events; however, they suffer from a more focused investigations. For this work, we use a catalog short baseline of weeks (e.g., Spitzer) to months (e.g., K2 of ; YSOs given by Gagn´e(2019), 413 of which are part and TESS). Furthermore, while K2 has been very success- 7 000 of the Lupus Star-Forming Region. ful with finding dippers, its limited viewing window has re- sulted in most surveys being conducted in the Taurus and Upper Sco regions. In addition to space telescopes, ground- 2.1 ASAS-SN Light Curves based observatories such as the Kilodegree Extremely Little Telescope (KELT; Pepper et al. 2007, 2012, 2018) have been The ASAS-SN Network consists of 20 telescopes mounted used for conducting surveys of YSOs. KELT has the advan- on 5 fully-robotic mounts located at the Haleakal¯aObserva- tage of a wider field than K2, but is limited to brighter stars tory, the Cerro Tololo International Observatory, McDonald (8<V <12 mag). Observatory, and the South African Astrophysical Observa- We performed a search for variable YSOs in the Lupus tory. Observations span from late 2012 to mid-2018 in the V region using the All-Sky Automated Survey for SuperNovae band, and since late 2017 in the g band. Each science image (ASAS-SN; Shappee et al. 2014; Kochanek et al. 2017) as consists of three dithered 90 s exposures taken by four 14-cm 00 part of a larger survey of transient objects. ASAS-SN of- aperture Nikon telephoto lenses with 8: 0 pixels. fers photometric data of the entire sky from late 2012 to Images from ASASS-SN are processed by the fully- mid 2018 in the V band, and from late 2017 to present in automated ASAS-SN pipeline using the ISIS image subtrac- the g band. The combination of a long baseline and all-sky tion package (Alard & Lupton 1998; Alard 2000). The IRAF 00 coverage allows for large surveys of many different types of apphot package is used with a 2-pixel (≈ 16: 0) aperture to variability. While the ASAS-SN cadence is slower than K2 perform aperture photometry on a subtracted image, gener- or KELT, ASAS-SN data fills an unexplored region of pa- ating a differential light curve. The same aperture is used to rameter space. It provides a far wider sky coverage than K2, perform photometry in a reference image, the result of which and has a deeper limiting magnitude than KELT. is added back to the differential light curve. The photome- try is then calibrated using field stars known in the AAVSO Earlier works in this series have utilized ASAS-SN to Photometric All-Sky Survey (Henden et al. 2015). search for variability. Paper I (Jayasinghe et al. 2018) re- ported ∼ 66; 000 new variables found during ASAS-SN's search for supernovae.
Load more

Recommended publications
  • The Spitzer C2d Survey of Large, Nearby, Interstellar Clouds. IV
    Draft version October 24, 2018 A Preprint typeset using LTEX style emulateapj v. 08/22/09 THE SPITZER C2D SURVEY OF LARGE, NEARBY, INTERSTELLAR CLOUDS. IV. LUPUS OBSERVED WITH MIPS Nicholas L. Chapman1, Shih-Ping Lai1,2,3, Lee G. Mundy1, Neal J. Evans II4, Timothy Y. Brooke5, Lucas A. Cieza4, William J. Spiesman4, Luisa M. Rebull6, Karl R. Stapelfeldt7, Alberto Noriega-Crespo6, Lauranne Lanz1, Lori E. Allen8, Geoffrey A. Blake9, Tyler L. Bourke8, Paul M. Harvey4, Tracy L. Huard8, Jes K. Jørgensen8, David W. Koerner10, Philip C. Myers8, Deborah L. Padgett6, Annelia I. Sargent5, Peter Teuben1, Ewine F. van Dishoeck11, Zahed Wahhaj12, & Kaisa E. Young4,13 Draft version October 24, 2018 ABSTRACT We present maps of 7.78 square degrees of the Lupus molecular cloud complex at 24, 70, and 160µm. They were made with the Spitzer Space Telescope’s Multiband Imaging Photometer for Spitzer (MIPS) instrument as part of the Spitzer Legacy Program, “From Molecular Cores to Planet-Forming Disks” (c2d). The maps cover three separate regions in Lupus, denoted I, III, and IV. We discuss the c2d pipeline and how our data processing differs from it. We compare source counts in the three regions with two other data sets and predicted star counts from the Wainscoat model. This comparison shows the contribution from background galaxies in Lupus I. We also create two color magnitude diagrams using the 2MASS and MIPS data. From these results, we can identify background galaxies and distinguish them from probable young stellar objects. The sources in our catalogs are classified based on their spectral energy distribution (SED) from 2MASS and Spitzer wavelengths to create a sample of young stellar object candidates.
    [Show full text]
  • Using Herschel and Planck Observations to Delineate the Role of Magnetic Fields in Molecular Cloud Structure
    Astronomy & Astrophysics manuscript no. 35779arxiv c ESO 2019 September 12, 2019 Using Herschel and Planck observations to delineate the role of magnetic fields in molecular cloud structure Juan D. Soler1 1. Max Planck Institute for Astronomy, Konigstuhl¨ 17, 69117, Heidelberg, Germany. [email protected] Received 26 APR 2019 / Accepted 07 AUG 2019 ABSTRACT We present a study of the relative orientation between the magnetic field projected onto the plane of sky (B?) on scales down to 0.4 pc, inferred from the polarized thermal emission of Galactic dust observed by Planck at 353 GHz, and the distribution of gas column density (NH) structures on scales down to 0.026 pc, derived from the observations by Herschel in submillimeter wavelengths, toward ten nearby (d < 450 pc) molecular clouds. Using the histogram of relative orientation technique in combination with tools from circular statistics, we found that the mean relative orientation between NH and B? toward these regions increases progressively ◦ ◦ from 0 , where the NH structures lie mostly parallel to B?, with increasing NH, in many cases reaching 90 , where the NH structures lie mostly perpendicular to B?. We also compared the relative orientation between NH and B? and the distribution of NH, which is characterized by the slope of the tail of the NH probability density functions (PDFs). We found that the slopes of the NH PDF tail are steepest in regions where NH and B? are close to perpendicular. This coupling between the NH distribution and the magnetic field suggests that the magnetic fields play a significant role in structuring the interstellar medium in and around molecular clouds.
    [Show full text]
  • These Sky Maps Were Made Using the Freeware UNIX Program "Starchart", from Alan Paeth and Craig Counterman, with Some Postprocessing by Stuart Levy
    These sky maps were made using the freeware UNIX program "starchart", from Alan Paeth and Craig Counterman, with some postprocessing by Stuart Levy. You’re free to use them however you wish. There are five equatorial maps: three covering the equatorial strip from declination −60 to +60 degrees, corresponding roughly to the evening sky in northern winter (eq1), spring (eq2), and summer/autumn (eq3), plus maps covering the north and south polar areas to declination about +/− 25 degrees. Grid lines are drawn at every 15 degrees of declination, and every hour (= 15 degrees at the equator) of right ascension. The equatorial−strip maps use a simple rectangular projection; this shows constellations near the equator with their true shape, but those at declination +/− 30 degrees are stretched horizontally by about 15%, and those at the extreme 60−degree edge are plotted twice as wide as you’ll see them on the sky. The sinusoidal curve spanning the equatorial strip is, of course, the Ecliptic −− the path of the Sun (and approximately that of the planets) through the sky. The polar maps are plotted with stereographic projection. This preserves shapes of small constellations, but enlarges them as they get farther from the pole; at declination 45 degrees they’re about 17% oversized, and at the extreme 25−degree edge about 40% too large. These charts plot stars down to magnitude 5, along with a few of the brighter deep−sky objects −− mostly star clusters and nebulae. Many stars are labelled with their Bayer Greek−letter names. Also here are similarly−plotted maps, based on galactic coordinates.
    [Show full text]
  • Supernova Star Maps
    Supernova Star Maps Which Stars in the Night Sky Will Go Su pernova? About the Activity Allow visitors to experience finding stars in the night sky that will eventually go supernova. Topics Covered Observation of stars that will one day go supernova Materials Needed • Copies of this month's Star Map for your visitors- print the Supernova Information Sheet on the back. • (Optional) Telescopes A S A Participants N t i d Activities are appropriate for families Cre with children over the age of 9, the general public, and school groups ages 9 and up. Any number of visitors may participate. Location and Timing This activity is perfect for a star party outdoors and can take a few minutes, up to 20 minutes, depending on the Included in This Packet Page length of the discussion about the Detailed Activity Description 2 questions on the Supernova Helpful Hints 5 Information Sheet. Discussion can start Supernova Information Sheet 6 while it is still light. Star Maps handouts 7 Background Information There is an Excel spreadsheet on the Supernova Star Maps Resource Page that lists all these stars with all their particulars. Search for Supernova Star Maps here: http://nightsky.jpl.nasa.gov/download-search.cfm © 2008 Astronomical Society of the Pacific www.astrosociety.org Copies for educational purposes are permitted. Additional astronomy activities can be found here: http://nightsky.jpl.nasa.gov Star Maps: Stars likely to go Supernova! Leader’s Role Participants’ Role (Anticipated) Materials: Star Map with Supernova Information sheet on back Objective: Allow visitors to experience finding stars in the night sky that will eventually go supernova.
    [Show full text]
  • Constellation Coloring Pages
    Constellation coloring pages OU Lynx Johann Bode, Uranographia (1801) Plate 6 (Ursa Major) Leo Minor the Little Lion, Ursa Major the Big Bear Plate 7 (Bootes) Bootes the Herdsman, Canes Venatici the Hunting Dogs, Coma Berenices the Hair of Berenice, Corona Borealis the Northern Crown, Mons Maenalus the Mountain, Quadrant Muralis the Mural Quadrant Plate 8 (Cygnus) Cygnus the Swan, Hercules, Lyra the Harp, Ramus Pomifer the Apple branch, Sagitta the Arrow, Vulpecula the Fox Plate 9 (Ophiuchus) Antinous the Servant, Aquila the Eagle, Ophiuchus the Snake Handler, Scutum the Shield, Serpens the Snake, The Bull of Poniatowski Plate 10 (Pegasus) Delphinus the Dolphin, Equuleus the Foal, Pegasus the Flying Horse Plate 12 (Orion and Taurus) Canis Minor the Little Dog, Gemini the Twins, Orion the Hunter, Psalterium Georgianum the Harp, Taurus the Bull Plate 14 (Virgo) Cauda Hydrae, Ears of wheat, Hydra the Water Snake, Libra the Balance, Virgo the Maiden Plate 15 (Sagittarius) Ara the Altar, Corona Australis the Southern Crown, Lupus the Wolf, Norma the Carpenter's Square, Scorpius the Scorpion, Tubus Herschelii Major the Telescope of Uranus Plate 17 (Cetus) Apparatus Chemicus, Cetus the Whale or Sea Monster, Eridanus the River, Fornax the Furnace, Machina Electrica the Electrostatic Generator, Sculptor the Sculptor's Workshop Plate 18 (Canis Major) Argo Navis, Caelum the Sculptor's Chisel, Canis Major the Big Dog, Caput Hydrum, Columba the Dove, Hydra the Water Snake, Lepus the Hare, Lochium Funis the Nautical Line of Argo Navis, Monoceros the Unicorn, Officina Typographica the Printing Press, Pyxis the Compass of Argo Navis Plate 19 (Hydra) Antlia the Air Pump, Argo Navis, Centaurus the Centaur, Corvus the Crow, Crater the Cup, Felis the Cat, Hydra the Water Snake Exhibit: Galileo’s World.
    [Show full text]
  • 81 Southern Objects for a 10” Telescope. 0-4Hr 4-8Hr 8-12Hr
    81 southern objects for a 10” telescope. 0-4hr NGC55|00h 15m 22s|-39 11’ 35”|33’x 5.6’|Sculptor|Galaxy| NGC104|00h 24m 17s|-72 03’ 30”|31’|Tucana|Globular NGC134|00h 30m 35s|-33 13’ 00”|8.5’x2’|Sculptor|Galaxy| ESO350-40|00h 37m 55s|-33 41’ 20”|1.5’x1.2’|Sculptor|Galaxy|The Cartwheel NGC300|00h 55m 06s|-37 39’ 24”|22’x15.5’|Sculptor|Galaxy| NGC330|00h 56m 27s|-72 26’ 37”|Tucana|1.9’|SMC open cluster| NGC346|00h 59m 14s|-72 09’ 19”|Tucana|5.2’|SMC Neb| ESO351-30|01h 00m 22s|-33 40’ 50”|60’x56’|Sculptor|Galaxy|Sculptor Dwarf NGC362|01h 03m 23s|-70 49’ 42”|13’|Tucana|Globular| NGC2573| 01h 37m 21s|-89 25’ 49”|Octans| 2.0x 0.8|galaxy|polarissima australis| NGC1049|02h 39m 58s|-34 13’ 52”|24”|Fornax|Globular| ESO356-04|02h 40m 09s|-34 25’ 43”|60’x100’|Fornax|Galaxy|Fornax Dwarf NGC1313|03h 18m 18s|-66 29’ 02”|9.1’x6.3’|Reticulum|Galaxy| NGC1316|03h 22m 51s|-37 11’ 22”|12’x8.5’|Fornax|Galaxy| NGC1365|03h 33m 46s|-36 07’ 13”|11.2’x6.2’|Fornax|Galaxy NGC1433|03h 42m 08s|-47 12’ 18”|6.5’x5.9’|Horologium|Galaxy| 4-8hr NGC1566|04h 20m 05s|-54 55’ 42”|Dorado|Galaxy| Reticulum Dwarf|04h 31m 05s|-58 58’ 00”|Reticulum|LMC globular| NGC1808|05h 07m 52s|-37 30’ 20”|6.4’x3.9’|Columba|Galaxy| Kapteyns Star|05h 11m 35s|-45 00’ 16”|Stellar|Pictor|Nearby star| NGC1851|05h 14m 15s|-40 02’ 30”|11’|Columba|Globular| NGC1962group|05h 26m 17s|-68 50’ 28”|?| Dorado|LMC neb/cluster NGC1968group|05h 27m 22s|-67 27’ 36”|12’ for group|Dorado| LMC Neb/cluster| NGC2070|05h 38m 37s|-69 05’ 52”|11’|Dorado|LMC Neb|Tarantula| NGC2442|07h 36m 24s|-69 32’ 38”|5.5’x4.9’|Volans|Galaxy|The meat hook| NGC2439|07h 40m 59s|-31 38’36”|10’|Puppis|Open Cluster| NGC2451|07h 45m 35s|-37 57’ 27”|45’|Puppis|Open Cluster| IC2220|07h 56m 57s|-59 06’ 00”|6’x4’|Carina|Nebula|Toby Jug| NGC2516|07h 58m 29s|-60 51’ 46”|29’|Carina|Open Cluster 8-12hr NGC2547|08h 10m 50s|-49 15’ 39”|20’|Vela|Open Cluster| NGC2736|09h 00m 27s|-45 57’ 49”|30’x7’|Vela|SNR|The Pencil| NGC2808|09h 12m 08s|-64 52’ 48”|12’|Carina|Globular| NGC2818|09h 16m 11s|-36 35’ 59”|9’|Pyxis|Open Cluster with planetary.
    [Show full text]
  • Messier Object Mapping System
    Messier Object Mapping System Messier Object Constellation Map# Messier Object Constellation Map# M1 Taurus 1-6 M56 Lyra 3 M2 Aquarius 8 M57 Lyra 3 M3 Canes Venatici 4-10 M58 Virgo IN2-5 M4 Scorpius 2 M59 Virgo IN2 M5 Scorpius 10 M60 Virgo IN2-5-9-10 M6 Scorpius 2 M61 Virgo IN2-5-8 M7 Scorpius 2 M62 Ophiuchus 2 M8 Sagittarius 2-IN1 M63 Canes Venatici 4 M9 Ophiuchus 2 M64 Coma Berenices 4-5 M10 Ophiuchus 2 M65 Leo 5 M11 Scutum 2 M66 Leo 5 M12 Ophiuchus 2 M67 Cancer 6 M13 Hercules 3 M68 Hydra 9 M14 Ophiuchus 2 M69 Sagittarius 2-IN1-8 M15 Pegasus 8 M70 Sagittarius 2-IN1-8 M16 Serpens 2-IN1 M71 Sagittarius 2 M17 Sagittarius 2-IN1 M72 Aquarius 8 M18 Sagittarius 2-IN1 M73 Aquarius 8 M19 Ophiuchus 2 M74 Pisces 11 M20 Sagittarius 2-IN1-8 M75 Sagittarius 8 M21 Sagittarius 2-IN1-8 M76 Perseus 7 M22 Sagittarius 2-IN1-8 M77 Cetus 11 M23 Sagittarius 2-IN1 M78 Orion 1 M24 Sagittarius 2-IN1 M79 Lepus 1 M25 Sagittarius 2-IN1-8 M80 Scorpius 2 M26 Scutum 2 M81 Ursa Major 4 M27 Vupecula 3 M82 Ursa Major 4 M28 Sagittarius 2-IN1-8 M83 Hydra 9 M29 Cygnus 3 M84 Virgo IN2-5 M30 Capricornus 8 M85 Coma Berenices 4-5 M31 Andromeda 7-11 M86 Virgo IN2-5 M32 Andromeda 7-11 M87 Virgo IN2-5 M33 Triangulum 7-11 M88 Coma Berenices IN2-5 M34 Perseus 7-11 M89 Virgo IN2 M35 Gemini 1-6 M90 Virgo IN2-5 M36 Auriga 1-6 M91 Virgo IN2-5 M37 Auriga 1-6 M92 Hercules 3 M38 Auriga 1 M93 Puppis 1-6 M39 Cygnus 3-7 M94 Canes Venatici 4-5 M40 Ursa Major 4 M95 Leo 5 M41 Canis Major 1 M96 Leo 5 M42 Orion 1 M97 Ursa Major 4 M43 Orion 1 M98 Coma Berenices IN2-4-5 M44 Sagittarius 6 M99 Coma Berenices IN2-4-5 M45 Taurus 1-11 M100 Coma Berenices IN2-4-5 M46 Puppis 1-6 M101 Ursa Major 4 M47 Puppis 1-6 M102 Draco 4 M48 Hydra 6 M103 Cassiopeia 7 M49 Virgo 2-IN1-8 M104 Virgo 5-9-10 M50 Monoceros 1-6 M105 Leo 5 M51 Canes Venatici 4-10 M106 Canes Venatici 4-5 M52 Cassiopeia 7 M107 Ophiuchus 2 M53 Coma Berenices 4-5-10 M108 Ursa Major 4 M54 Sagittarius 2-IN1-8 M109 Ursa Major 4-5 M55 Sagittarius 2-8 M110 Andromeda 7-11 Messier Object List # NGC# Constellation Type Name, If Any Mag.
    [Show full text]
  • THE SKY TONIGHT Constellation Is Said to Represent Ganymede, the Handsome Prince of Capricornus Troy
    - October Oketopa HIGHLIGHTS Aquarius and Aquila In Greek mythology, the Aquarius THE SKY TONIGHT constellation is said to represent Ganymede, the handsome prince of Capricornus Troy. His good looks attracted the attention of Zeus, who sent the eagle The Greeks associated Capricornus Aquila to kidnap him and carry him with Aegipan, who was one of the to Olympus to serve as a cupbearer Panes - a group of half-goat men to the gods. Because of this story, who often had goat legs and horns. Ganymede was sometimes seen as the god of homosexual relations. He Aegipan assumed the form of a fish- also gives his name to one of the tailed goat and fled into the ocean moons of Jupiter, which are named to flee the great monster Typhon. after the lovers of Zeus. Later, he aided Zeus in defeating Typhon and was rewarded by being To locate Aquarius, first find Altair, placed in the stars. the brightest star in the Aquila constellation. Altair is one of the To find Capricornus (highlighted in closest stars to Earth that can be seen orange on the star chart), first locate with the naked eye, at a distance the Aquarius constellation, then of 17 light years. From Altair, scan look to the south-west along the east-south-east to find Aquarius ecliptic line (the dotted line on the (highlighted in yellow on the star chart). star chart). What’s On in October? October shows at Perpetual Guardian Planetarium, book at Museum Shop or online. See website for show times and - details: otagomuseum.nz October Oketopa SKY GUIDE Capturing the Cosmos Planetarium show.
    [Show full text]
  • Radial Velocity Measurements of B Stars in the Scorpius-Centaurus Association
    A&A 448, 1001–1006 (2006) Astronomy DOI: 10.1051/0004-6361:20041614 & c ESO 2006 Astrophysics Radial velocity measurements of B stars in the Scorpius-Centaurus association E. Jilinski1,2,S.Daflon1, K. Cunha1, and R. de la Reza1 1 Observatório Nacional/MCT, Rua Gal. Jose Cristino 77, São Cristovão, Rio de Janeiro, Brazil e-mail: [email protected] 2 Main Astronomical Observatory, Pulkovo, St. Petersburg, Russia Received 7 July 2004 / Accepted 30 October 2005 ABSTRACT We derive single-epoch radial velocities for a sample of 56 B-type stars members of the subgroups Upper Scorpius, Upper Centaurus Lupus and Lower Centaurus Crux of the nearby Sco-Cen OB association. The radial velocity measurements were obtained by means of high-resolution echelle spectra via analysis of individual lines. The internal accuracy obtained in the measurements is estimated to be typically 2–3 km s−1, but depends on the projected rotational velocity of the target. Radial velocity measurements taken for 2–3 epochs for the targets HD 120307, HD 142990 and HD 139365 are variable and confirm that they are spectroscopic binaries, as previously identified in the literature. Spectral lines from two stellar components are resolved in the observed spectra of target stars HD 133242, HD 133955 and HD 143018, identifying them as spectroscopic binaries. Key words. stars: early-type – stars: binaries: spectroscopic – stars: kinematics – techniques: radial velocities – open clusters and associations: individual: Scorpius-Centaurus association 1. Introduction until their main first orbits confinement was found, as well as the past mean positions of LCC and UCL. This enabled not The Scorpius-Centaurus association is the nearest associa- only to determine the dynamical age of this moving group, tion of young OB stars to the Sun.
    [Show full text]
  • THE CONSTELLATION CIRCINUS, the COMPASS Circinus Is a Small
    THE CONSTELLATION CIRCINUS, THE COMPASS Circinus is a small faint constellation in the southern sky, first defined in 1756 by French astronomer Nicolas Louis de Lacaille. Its name is Latin for compass, referring to the drafting tool used for drawing circles (it should not be confused with Pyxis, a constellation that represents a mariner's compass which points north). Its brightest star is Alpha Circini, with an apparent magnitude of 3.19. Slightly variable, it is the brightest rapidly oscillating Ap star in the night sky(peculiar stars showing an abundances of some metals. AX Circini is a Cepheid variable visible with the unaided eye, and BX Circini is a faint star thought to have been formed from the merger of two white dwarfs. Two sun-like stars have planetary systems: HD 134060 has two small planets, and HD 129445 has a Jupiter-like planet. Supernova SN 185 appeared in Circinus in 185 AD and was recorded by Chinese observers. Two novae have been observed more recently, in the 20th century.The Milky Way runs through the constellation, featuring prominent objects such as the open cluster NGC 5823 and the planetary nebula NGC 5315. Circinus hosts one notable spiral galaxy, the Circinus Galaxy, which was discovered in 1977 and is the closest Seyfert galaxy to the Milky Way. Seyfert galaxies are named after Carl Seyfert (1911 - 1960), an American astronomer who The Circinus Galaxy, a first described this class in 1943, and Type II Seyfert galaxy are intensely studied objects in astronomy. They are thought to be powered by the same phenomena that occur in quasars, but unlike quasars, their host galaxies are clearly detectable.
    [Show full text]
  • SFA Star Charts
    Nov 20 SFA Star Chart 1 - Northern Region 0h Dec 6 Nov 5 h 23 30º 1 h d Dec 21 h p Oct 21h s b 2 h 22 ANDROMEDA - Daughter of Cepheus and Cassiopeia Mirach Local Meridian for 8 PM q m ANTLIA - Air Pumpe p 40º APUS - Bird of Paradise n o i b g AQUILA - Eagle k ANDROMEDA Jan 5 u TRIANGULUM AQUARIUS - Water Carrier Oct 6 h z 3 21 LACERTA l h ARA - Altar j g ARIES - Ram 50º AURIGA - Charioteer e a BOOTES - Herdsman j r Schedar b CAELUM - Graving Tool x b a Algol Jan 20 b o CAMELOPARDALIS - Giraffe h Caph q 4 Sep 20 CYGNUS k h 20 g a 60º z CAPRICORNUS - Sea Goat Deneb z g PERSEUS d t x CARINA - Keel of the Ship Argo k i n h m a s CASSIOPEIA - Ethiopian Queen on a Throne c h CASSIOPEIA g Mirfak d e i CENTAURUS - Half horse and half man CEPHEUS e CEPHEUS - Ethiopian King Alderamin a d 70º CETUS - Whale h l m Feb 5 5 CHAMAELEON - Chameleon h i g h 19 Sep 5 i CIRCINUS - Compasses b g z d k e CANIS MAJOR - Larger Dog b r z CAMELOPARDALIS 7 h CANIS MINOR - Smaller Dog e 80º g a e a Capella CANCER - Crab LYRA Vega d a k AURIGA COLUMBA - Dove t b COMA BERENICES - Berenice's Hair Aug 21 j Feb 20 CORONA AUSTRALIS - Southern Crown Eltanin c Polaris 18 a d 6 d h CORONA BOREALIS - Northern Crown h q g x b q 30º 30º 80º 80º 40º 70º 50º 60º 60º 70º 50º CRATER - Cup 40º i e CRUX - Cross n z b Rastaban h URSA CORVUS - Crow z r MINOR CANES VENATICI - Hunting Dogs p 80º b CYGNUS - Swan h g q DELPHINUS - Dolphin Kocab Aug 6 e 17 DORADO - Goldfish q h h h DRACO o 7 DRACO - Dragon s GEMINI t t Mar 7 EQUULEUS - Little Horse HERCULES LYNX z i a ERIDANUS - River j
    [Show full text]
  • Globular Clusters
    v 2016-07-07 <<< The 110 Best Globular Clusters >>> Page 1 of 2 ^NGC Name Type Mag Size RA DEC Date Constellation 288 GC 8.1 13' 00:52.8 -26° 35' Oct 19 Sculptor formax 2 GC 13.5 1' 02:38.7 -34° 49' Oct 29 Fornax 1049 fornax 3 GC 12.6 1' 02:39.8 -34° 15' Oct 29 Fornax formax 4 GC 13.6 1' 02:40.1 -34° 32' Oct 29 Fornax formax 5 GC 13.4 1' 02:42.3 -34° 06' Oct 30 Fornax palomar 1 GC 13.6 3' 03:33.4 +79° 35' Nov 12 Cepheus palomar 2 GC 13.0 2' 04:46.1 +31° 23' Dec 01 Auriga 1851 GC 7.1 12' 05:14.1 -40° 03' Dec 09 Columba 1904 M79 GC 7.7 10' 05:24.2 -24° 31' Dec 11 Lepus 2298 GC 9.3 5' 06:49.0 -36° 00' Jan 02 Puppis 2419 GC 10.4 5' 07:38.1 +38° 53' Jan 14 Lynx pyxis GC 12.9 2' 09:07.9 -37° 14' Feb 06 Pyxis palomar 3 GC 13.9 2' 10:05.5 +00° 04' Feb 20 Sextans 3201 GC 6.8 20' 10:17.6 -46° 25' Feb 23 Vela 4147 GC 10.3 4' 12:10.1 +18° 33' Apr 06 Coma Berenices 4590 M68 GC 7.8 11' 12:39.5 -26° 45' Apr 16 Hydra 5024 M53 GC 7.6 13' 13:12.9 +18° 10' Apr 24 Coma Berenices 5053 GC 9.5 10' 13:16.5 +17° 43' Apr 25 Coma Berenices 5139 Omega Centaurus GC 7.7 55' 13:26.8 -47° 29' Apr 27 Centaurus 5272 M3 GC 6.2 18' 13:42.2 +28° 23' May 02 Canes Venatici 5466 GC 9.0 9' 14:05.5 +28° 32' May 07 Bootes 5634 GC 9.5 6' 14:29.6 -05° 59' May 14 Virgo 5694 GC 10.2 4' 14:39.6 -26° 32' May 16 Hydra 5824 GC 9.1 7' 15:04.0 -33° 04' May 22 Lupus palomar 5 GC 11.8 5' 15:16.1 -00° 07' May 26 Serpens 5897 GC 8.5 11' 15:17.5 -21° 01' May 26 Libra 5904 M5 GC 5.7 23' 15:18.6 +02° 05' May 27 Serpens 5986 GC 7.5 10' 15:46.1 -37° 47' Jun 01 Lupus 6093 M80 GC 7.3 10' 16:17.0 -22°
    [Show full text]