চিত্র:M101 UIT.gif

সারাংশ

This ultraviolet image of the giant spiral galaxy Messier 101 (M101) was obtained by the Ultraviolet Imaging Telescope during the Astro-2 mission of the Space Shuttle Endeavour.

M101 is an Sc-type galaxy, meaning a spiral galaxy with a relatively small central bulge and a system of spiral arms that is not tightly wound. At a distance of about 16 million light years, it is considered relatively close to the Earth.

M101 is known to contain many giant HII regions, meaning huge glowing nebulae shine as a result of ultraviolet radiation from the massive stars within them. The UIT images will be used to determine the far-ultraviolet energy outputs of these stars and nebulae. Also, the astronomers will study the ages of the nebulae, their dust contents, and the "initial mass functions" of their stars, meaning the relative numbers of stars of different masses when they first formed in the nebulae. This is equivalent to finding the relative numbers of newborn babies of different weights. The investigators will also determine the total mass of all the young massive stars in each HII region or nebula.

Source

• http://archive.stsci.edu/uit/project/Astro2/Astro2_pictures.html

লাইসেন্স প্রদান

	এই ফাইলটি পাবলিক ডোমেইনে আছে কারণ এটি শুধুমাত্র নাসা কর্তৃক নির্মিত হয়েছিল। নাসার কপিরাইট নীতি হচ্ছে যে "নাসা কর্তৃক উল্লেখ না থাকলে নাসার উপাদান কপিরাইট দ্বারা সুরক্ষিত নয়"। (Template:PD-USGov, নাসার কপিরাইট নীতির পাতা অথবা জেপিএল চিত্র ব্যবহারের নীতি দেখুন।)
	সতর্কবার্তা: Use of NASA logos, insignia and emblems are restricted per US law 14 CFR 1221. The NASA website hosts a large number of images from the Soviet/Russian space agency, and other non-American space agencies. These are not necessarily in the public domain. Materials based on Hubble Space Telescope data may be copyrighted if they are not explicitly produced by the STScI.[1] See also {{PD-Hubble}} and {{Cc-Hubble}}. The SOHO (ESA & NASA) joint project implies that all materials created by its probe are copyrighted and require permission for commercial non-educational use. [2] Images featured on the Astronomy Picture of the Day (APOD) web site may be copyrighted. [3]