Contains:M 52, NGC 7654, Bubble nebula, NGC 7635
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M52 and the Bubble Nebula, 


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M52 and the Bubble Nebula

M52 and the Bubble Nebula

Technical card

Imaging telescope or lens:Takahashi FSQ-106N FSQ

Imaging camera:QSI 683 wsg-8 QSI

Mount:apt1200gto AP1200

Guiding telescope or lens:Takahashi FSQ-106N FSQ

Guiding camera:QSI 683 wsg-8 QSI

Software:CCD Autopilot 5

Resolution: 2865x2038

Dates: Sept. 22, 2017

Frames: 30x600"

Integration: 5.0 hours

Avg. Moon age: 2.26 days

Avg. Moon phase: 5.67% job: 1871774

RA center: 350.718 degrees

DEC center: 61.369 degrees

Pixel scale: 2.104 arcsec/pixel

Orientation: 2.536 degrees

Field radius: 1.027 degrees

Locations: ImagingInfinity Observatory, Bethune, SC, United States


In the constellation of Cassiopeia there lies two interesting objects within the same field of view. The open star cluster M52...some 190 stars linked by gravity and lying at a distance of 3000 to 7000 light years (accurate distance measurements are difficult because of intervening galactic dust). The other object is NGC 7635, the beautiful Bubble Nebula.

Looking like a celestial Christmas tree ornament, this is the beautiful "Bubble Nebula", known officially as NGC7635. Is is formed by gas being compressed by a strong stellar wind from massive star BD+602522, forty times as massive as our sun and several hundred thousand times more luminous. As fast moving gas escapes the star, it compresses surrounding sparse gas into a shell. The shell, consisting of hydrogen, oxygen and sulfur, is ionized by the radiation from BD+602522 causing it to glow. The bubble is approximately 6 light-years in diameter.

BD+602522 is a "Wolf-Rayet" star, a star in the end stages of its life which emits fierce stellar winds (charged particles streaming from its surface) rapidly depleting its mass until it finally dies in a supernova. Wolf-Rayet stars (named for their discoverers) have surface temperatures between 30,000 and 60,000 degrees Kelvin and emit stellar winds with speeds exceeding 1500 kilometers per second. There are only about 300 Wolf-Rayet stars known in our galaxy.

A closer view of the Bubble can be seen at



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Sky plot

Sky plot


M52 and the Bubble Nebula, 


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