Astronomy



Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer.

2021 January 24

Massive Nearby Spiral Galaxy NGC 2841
Image Credit: NASA,ESA,Hubble, Subaru; Composition & Copyright: Roberto Colombari

Explanation: It is one of the more massive galaxies known.A mere 46 million light-years distant, spiral galaxy NGC 2841can be found in the northern constellation ofUrsa Major.This sharp view of the gorgeousisland universeshows off a striking yellow nucleus and galactic disk.Dust lanes, small, pink star-forming regions, and young blue star clustersare embedded in the patchy, tightlywoundspiral arms.In contrast, many other spiralsexhibit grand, sweeping arms with large star-forming regions. NGC 2841 has a diameter of over 150,000 light-years, even larger thanour ownMilky Way.The featured composite image merges exposures from the orbiting 2.4-meter Hubble Space Telescope and the ground-based 8.2-meter Subaru Telescope. X-ray imagessuggest that resulting winds and stellar explosions createplumes of hot gas extending into a halo around NGC 2841.

Tomorrow's picture:
  • Astronomy, science that encompasses the study of all extraterrestrial objects and phenomena. Since the late 19th century, astronomy has expanded to include astrophysics, the application of physical.
  • Chapter Outline 1.1 The Nature of Astronomy 1.2 The Nature of Science 1.3 The Laws of Nature 1.4 Numbers in Astronomy 1.5 Consequences of Light Travel Time.

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Astronomers selected an uncluttered area of the sky in the constellation Ursa Major (the Big Bear) and pointed the Hubble Space Telescope at a single spot for 10 days. The many, separate exposures combined made the Deep Field image above. (Image courtesy of R. Williams, as presented on NASA's Astronomy Picture of the Day site.)

Instructor(s)

Prof. Saul Rappaport

MIT Course Number

8.282J / 12.402J

As Taught In

Spring 2006

Level

Undergraduate

Some Description

Instructor(s)

Prof.

As Taught In

Spring 2002

Course Number

2.24

Level

Undergraduate/Graduate

Features

Lecture Notes, Student Work

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Course Description

Course Features

Course Description

Astronomy

Introduction to Astronomy provides a quantitative introduction to the physics of the solar system, stars, the interstellar medium, the galaxy, and the universe, as determined from a variety of astronomical observations and models.

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