We estimate the conversion factor relating CO emission to H2 mass, ЮБCO, in five Local Group galaxies that span approximately an order of magnitude in metallicityт?? ... We model the dust mass along the line of sight from infrared (IR) emission and then solve for the ЮБCO that best allows a single gas-to-dust ratio (ЮДGDR) to describe each system. ... These results are consistent with the conversion factor becoming a strong function of metallicity around 12 + log (O/H) ~ 8.4-8.2. ...

Еще в разделе: (Показать все результаты (>11910) - www.stsci.edu/ )

• USA Weekend Magazine, 22 March 1998
• MSNBC, 23 March 1998
• GOODS: The Great Observatories Origins Deep Survey

... To make it easier to "read" this celestial calendar, they grouped the brighter stars into readily recognizable shapes, the constellations. ... From Star Maps , [AS 289] a constellation slide set, available from the ASP . Our modern constellation system comes to us from the ancient Greeks. ... The ancient Greek tradition was to name stars by their position within a constellation. ... And it explains why we have a system of Greek constellations with Latin names containing stars with Arabic names. ...

Еще в разделе: (Показать все результаты (>1261) - www.astrosociety.org/ )

• ASP: Star Science in the Autumn Sky
• ASP: Indiana Jones and the Astronomers of Yore
• ASP: The Universe At Your Fingertips Activities TOC

The apparent path of the Sun across the sky. ... The path of the Sun across the celestial sphere is very close to that of the planets and the moon. ... In one year, as the Earth completes a full circuit around the Sun (drawing above), the Earth-Sun line and its continuation past Earth sweep the entire plane. ... Since the Sun and Earth are in the plane of the ecliptic, the line is automatically in that plane too; if the moon is also on the same line, it must be in the plane of the ecliptic as well. ...

Еще в разделе: (Показать все результаты (>424) - www.iki.rssi.ru/ )

• Precession
• Jupiter Moon Callisto
• Discovery of the Solar System

... Users . ... AAS 225 . ... This particular part of the analysis has been disabled since the code is struggling to cope with the number of users seen this year, in particular the large contingent of people who have re-tweeted NASA. ... The links between the accounts identify those users who have mentioned another user in a tweet, using the @name syntax; the line widths increase based on the number of mentions but given that the graph is ever-so-slightly crowded this isn't that useful at this time. ...

Еще в разделе: (Показать все результаты (>3710) - hea-www.harvard.edu/ )

• A constellation of tweets from #AAS221
• A constellation of tweets from #AAS223
• activities

... For a long time, astronomers found it very difficult to make a map of the very centre of our Galaxy, the Milky Way. ... You can imagine the Milky Way as a CD with a ball of cotton wool slotted through the hole in its centre. ... It s one the oldest and most impressive features of the Galaxy, but it was not very well understood until now. ... Cool fact : Did you know that Earth, the Sun and our entire Solar System are orbiting around the centre of the Milky Way at thousands of kilometres per hour. ...

Еще в разделе: (Показать все результаты (>33934) - www.eso.org/ )

• http://www.eso.org/public/news/eso1518/kids/
• http://www.eso.org/public/news/eso1210/kids/
• Panning across VISTAтАЩs infrared image of the globular star cluster Messier 55