Properties of Wolf-Rayet Stars - Paul Crowther, University of Sheffield
... WR stars can readily be obtained (e.g. Willis et al. 2004). Alternatively, optical and near-IR He i P Cygni profiles or mid-IR fine-structure metal lines may be used to derive reliable wind velocities (Howarth & Schmutz 1992; Dessart et al. 2000), for which the radial dependence is assumed to follow ...
... WR stars can readily be obtained (e.g. Willis et al. 2004). Alternatively, optical and near-IR He i P Cygni profiles or mid-IR fine-structure metal lines may be used to derive reliable wind velocities (Howarth & Schmutz 1992; Dessart et al. 2000), for which the radial dependence is assumed to follow ...
Chapter 1 The Discovery of Open Clusters - Willmann-Bell
... In the legends of the Kiowa people of North America, the massive Devil’s Tower rock formation in Wyoming was created by the Great Spirit to protect seven Indian maidens who were being pursued by bears. The maidens were subsequently placed in the sky as the Pleiades cluster. These stars were also imp ...
... In the legends of the Kiowa people of North America, the massive Devil’s Tower rock formation in Wyoming was created by the Great Spirit to protect seven Indian maidens who were being pursued by bears. The maidens were subsequently placed in the sky as the Pleiades cluster. These stars were also imp ...
A spectroscopic investigation of the O
... Results. We confirm the binarity for four objects: HD 193443, HD 228989, HD 229234, and HD 194649. We derive for the first time the orbital solutions of three systems, and we confirm the values of the fourth, showing that these four systems all have orbital periods shorter than 10 days. Besides thes ...
... Results. We confirm the binarity for four objects: HD 193443, HD 228989, HD 229234, and HD 194649. We derive for the first time the orbital solutions of three systems, and we confirm the values of the fourth, showing that these four systems all have orbital periods shorter than 10 days. Besides thes ...
PDF - ASSA
... radiation from the O-type stars. On their exposed surfaces, pillars are created. Some of the pillars detach from their parent molecular cloud creating isolated globules, often with a young star located near the apex of the globule. A new study of the region, A Survey of Irradiated Pillars, Globules, ...
... radiation from the O-type stars. On their exposed surfaces, pillars are created. Some of the pillars detach from their parent molecular cloud creating isolated globules, often with a young star located near the apex of the globule. A new study of the region, A Survey of Irradiated Pillars, Globules, ...
I. Constellations
... II. Ecliptic: Over the course of a year, the ___Sun____ changes its relative position in the sky against the background stars. This is due to the orbital motion of the Earth. The yearly __ path ___ the Sun takes across the sky is called the ecliptic. III. Zodiac Constellations: The ___ecliptic____ p ...
... II. Ecliptic: Over the course of a year, the ___Sun____ changes its relative position in the sky against the background stars. This is due to the orbital motion of the Earth. The yearly __ path ___ the Sun takes across the sky is called the ecliptic. III. Zodiac Constellations: The ___ecliptic____ p ...
Sky Watcher - Boise Astronomical Society
... and fainter Mercury lower in the northwest. Mercury and Jupiter will be the brightest two stars between the west and northwest. There’s a possible new meteor shower in the offing! The reason is that Comet LINEAR 209P, which an automated telescope discovered in 2004, is passing through the inner sola ...
... and fainter Mercury lower in the northwest. Mercury and Jupiter will be the brightest two stars between the west and northwest. There’s a possible new meteor shower in the offing! The reason is that Comet LINEAR 209P, which an automated telescope discovered in 2004, is passing through the inner sola ...
Navigating the Night Sky Checklist
... objects that are visible to the naked eye. A very good source is the monthly Sky Map available on the TAAS Fab 50 website. (www.TAAS.org) 2. Identify the constellation that the naked eye object is in. 3. Using your sky map or planisphere , locate the constellation in the night sky. 4. Identify a bri ...
... objects that are visible to the naked eye. A very good source is the monthly Sky Map available on the TAAS Fab 50 website. (www.TAAS.org) 2. Identify the constellation that the naked eye object is in. 3. Using your sky map or planisphere , locate the constellation in the night sky. 4. Identify a bri ...
Wolf-Rayet Stars
... (WNL). Similarly WC4-6 stars are designated as WCE, while WC7-9 stars are designated as WCL. Although there are important exceptions, WNE stars generally show no evidence for H emission while H emission is present in WNL stars. The distribution of Population I W-R stars, which are discussed in this ...
... (WNL). Similarly WC4-6 stars are designated as WCE, while WC7-9 stars are designated as WCL. Although there are important exceptions, WNE stars generally show no evidence for H emission while H emission is present in WNL stars. The distribution of Population I W-R stars, which are discussed in this ...
Infrared Properties of Star-Forming Dwarf Galaxies. I. Dwarf Irregular
... The observing facilities to which we had access imposed two additional criteria on our sample: 3. An apparent size smaller than 30 , possible to image by both facilities used for this work. 4. Target visibility from each facility during the observing time granted. We identified 34 dwarf galaxies th ...
... The observing facilities to which we had access imposed two additional criteria on our sample: 3. An apparent size smaller than 30 , possible to image by both facilities used for this work. 4. Target visibility from each facility during the observing time granted. We identified 34 dwarf galaxies th ...
on the pms star hbc 498 and its associated nebulous stars1
... HBC 495 and DL Ori/G2 have Li Iλ6708 Å strong in absorption (see Fig. 2 and Table 3), with equivalent widths stronger than the richest Li I stars with similar spectral types in the Pleiades cluster (i.e., “Li I rich stars”). The Li I line is apparently present in the spectrum of HBC 496, but the sp ...
... HBC 495 and DL Ori/G2 have Li Iλ6708 Å strong in absorption (see Fig. 2 and Table 3), with equivalent widths stronger than the richest Li I stars with similar spectral types in the Pleiades cluster (i.e., “Li I rich stars”). The Li I line is apparently present in the spectrum of HBC 496, but the sp ...
Early-type stars in the core of the young open cluster Westerlund 2
... is dominated by strong and broad H Balmer lines. Weak absorption lines of He λλ 4388, 4471, Mg λ 4481 and Si λ 4552 are also seen. The He λ 4471/Mg λ 4481 intensity ratio indicates a spectral type B8-A0. The appearance of some weak metallic lines favours an A0 classification, whilst ...
... is dominated by strong and broad H Balmer lines. Weak absorption lines of He λλ 4388, 4471, Mg λ 4481 and Si λ 4552 are also seen. The He λ 4471/Mg λ 4481 intensity ratio indicates a spectral type B8-A0. The appearance of some weak metallic lines favours an A0 classification, whilst ...
SherwoodWA_1973redux - Edinburgh Research Archive
... 1970; Gottesman and Davis, 1970) found that the HII regions and blue supergiants (in associations) lie within the ...
... 1970; Gottesman and Davis, 1970) found that the HII regions and blue supergiants (in associations) lie within the ...
a wide-field survey for variable stars
... Tauri variable stars. The nearby dusty, yellow cloud is Hind’s Variable Nebula (NGC 1555/1554). Over 400 light-years away, at the edge of a molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing ...
... Tauri variable stars. The nearby dusty, yellow cloud is Hind’s Variable Nebula (NGC 1555/1554). Over 400 light-years away, at the edge of a molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing ...
Notes on Stars
... Note: parsecs are the standard distance unit in astrophysics. Parsec means parallax second. The radius of the earth orbit, seen from a distance of 1 pc corresponds to an angular distance of 1 arcsec. ...
... Note: parsecs are the standard distance unit in astrophysics. Parsec means parallax second. The radius of the earth orbit, seen from a distance of 1 pc corresponds to an angular distance of 1 arcsec. ...
Luminosity, Flux and Magnitudes Outline
... Parallaxes are the key to knowing distances in the universe. Nearby stars are the stepping stone to measuring distance to everything else in the universe. We can now compute the luminosity of stars! ...
... Parallaxes are the key to knowing distances in the universe. Nearby stars are the stepping stone to measuring distance to everything else in the universe. We can now compute the luminosity of stars! ...
Open clusters in the Third Galactic Quadrant III. Alleged binary
... Of the four candidate pairs, only NGC 2383/NGC 2384 are close to each other, but have different metallicities and ages. Ruprecht 72 and Ruprecht 158 are not clusters but fluctuations of the field stellar density. Haffner 18 is found to be the superposition of two stellar groups at different distances: ...
... Of the four candidate pairs, only NGC 2383/NGC 2384 are close to each other, but have different metallicities and ages. Ruprecht 72 and Ruprecht 158 are not clusters but fluctuations of the field stellar density. Haffner 18 is found to be the superposition of two stellar groups at different distances: ...
Abd al-Rahman al-Sufi and his book of the fixed stars: a journey of
... important books in the history of Arabic and Islamic astronomy. This book was called Șuwar al-Kawākib al-Thamāniyah wa-al-Ārba'een, later known by its short name The Book of the Fixed Stars. It was written in Arabic by the famous Persian author and astronomer ′Abd alRaḥmān al-Ṣūfī around A.D. 964. E ...
... important books in the history of Arabic and Islamic astronomy. This book was called Șuwar al-Kawākib al-Thamāniyah wa-al-Ārba'een, later known by its short name The Book of the Fixed Stars. It was written in Arabic by the famous Persian author and astronomer ′Abd alRaḥmān al-Ṣūfī around A.D. 964. E ...
Stars: Intro & Classification Astronomy 1 — Elementary Astronomy LA Mission College
... Astronomy 1 — Elementary Astronomy LA Mission College Spring F2015 ...
... Astronomy 1 — Elementary Astronomy LA Mission College Spring F2015 ...
MPhil Thesis - Final - Suzanne Knight
... While post main sequence evolution pose barriers to close planetary companions for white dwarfs, giant planets have nevertheless been detected, such as the confirmed ~ 2.5 MJup planetary companion at a distance ~ 43 AU from its primary located in the 2M1207 system (Sigurdsson et al. 2003; Chauvin et ...
... While post main sequence evolution pose barriers to close planetary companions for white dwarfs, giant planets have nevertheless been detected, such as the confirmed ~ 2.5 MJup planetary companion at a distance ~ 43 AU from its primary located in the 2M1207 system (Sigurdsson et al. 2003; Chauvin et ...
bode elert johann
... astronomy Johann Elert Bode (1747–1826) had presented them as early as 1776.11 The numbers are contained in the Sammlung Astronomischer Tafeln, a three-volume collection of astronomical tables, made in partnership with Johann Heinrich Lambert and Johann Karl Gottlieb Schulze. Vol. i contains an 89-p ...
... astronomy Johann Elert Bode (1747–1826) had presented them as early as 1776.11 The numbers are contained in the Sammlung Astronomischer Tafeln, a three-volume collection of astronomical tables, made in partnership with Johann Heinrich Lambert and Johann Karl Gottlieb Schulze. Vol. i contains an 89-p ...
Red supergiants around the obscured open cluster Stephenson 2
... Context. Several clusters of red supergiants have been discovered in a small region of the Milky Way close to the base of the ScutumCrux Arm and the tip of the Long Bar. Population synthesis models indicate that they must be very massive to harbour so many supergiants. Amongst these clusters, Stephe ...
... Context. Several clusters of red supergiants have been discovered in a small region of the Milky Way close to the base of the ScutumCrux Arm and the tip of the Long Bar. Population synthesis models indicate that they must be very massive to harbour so many supergiants. Amongst these clusters, Stephe ...
November Celestial Calendar by Dave Mitsky All times are UT
... through southern Aries. It lies a bit more than two degrees south of the sixth-magnitude star 19 Arietis on the nights of November 11 and November 12. Asteroid 216 Kleopatra is at opposition in Taurus on November 16. For information on this year’s bright asteroids and upcoming asteroid occultation e ...
... through southern Aries. It lies a bit more than two degrees south of the sixth-magnitude star 19 Arietis on the nights of November 11 and November 12. Asteroid 216 Kleopatra is at opposition in Taurus on November 16. For information on this year’s bright asteroids and upcoming asteroid occultation e ...
Rotation Periods of Wide Binaries in the Kepler Field
... Because most of the stars that satisfy the present criteria are relatively nearby, they should be expected to have low interstellar reddening. In any case, since the two components presumably lie at the same distance, the reddening would be expected to be the same, and so will not affect Figure 1. T ...
... Because most of the stars that satisfy the present criteria are relatively nearby, they should be expected to have low interstellar reddening. In any case, since the two components presumably lie at the same distance, the reddening would be expected to be the same, and so will not affect Figure 1. T ...
A physical interpretation of the `red Sirius` anomaly
... millennia, of which the most widely discussed is the proposal that the white dwarf Sirius B was a red giant as recently as 2000 years ago. Extrinsic hypotheses are concerned with the possibility of transient reddening in an intervening medium through which the star is observed, such as might be caus ...
... millennia, of which the most widely discussed is the proposal that the white dwarf Sirius B was a red giant as recently as 2000 years ago. Extrinsic hypotheses are concerned with the possibility of transient reddening in an intervening medium through which the star is observed, such as might be caus ...
Canis Minor
Canis Minor /ˌkeɪnɨs ˈmaɪnər/ is a small constellation in the northern celestial hemisphere. In the second century, it was included as an asterism, or pattern, of two stars in Ptolemy's 48 constellations, and it is counted among the 88 modern constellations. Its name is Latin for ""lesser dog"", in contrast to Canis Major, the ""greater dog""; both figures are commonly represented as following the constellation of Orion the hunter.Canis Minor contains only two stars brighter than the fourth magnitude, Procyon (Alpha Canis Minoris), with a magnitude of 0.34, and Gomeisa (Beta Canis Minoris), with a magnitude of 2.9. The constellation's dimmer stars were noted by Johann Bayer, who named eight stars including Alpha and Beta, and John Flamsteed, who numbered fourteen. Procyon is the seventh-brightest star in the night sky, as well as one of the closest. A yellow-white main sequence star, it has a white dwarf companion. Gomeisa is a blue-white main sequence star. Luyten's Star is a ninth-magnitude red dwarf and the Solar System's next closest stellar neighbour in the constellation after Procyon. The fourth-magnitude HD 66141, which has evolved into an orange giant towards the end of its life cycle, was discovered to have a planet in 2012. There are two faint deep sky objects within the constellation's borders. The 11 Canis-Minorids are a meteor shower that can be seen in early December.