ASTRO:
     type=Supernova Remnant
     mag=7.0
     const=Cygnus
     dist=2400 ly
     size=30 ly
IMAGE:
     location=EB Driveway
     BrtlCls=4
     moon=23% WxCr
     exposure=CMOS OSC, 36x300s (3.0h), G100
     palette=HOO
EQUIPMENT:
​     optics=ES102CF APO / Stellarvue 1.0x fld-fltnr, FL=714mm, f/7.0
     camera=ZWO ASI2600MC-Pro
     filter=Optolong L-eXtreme duo NB
     mount=Celestron AVX
     guiding=Orion 60x240mm, ZWO ASi224MC
SOFTWARE:
     acquisition=Stellarium, APT, PHD2
     processing=PixInsight  (RCAstro), Photoshop (Lumenzia, APF-R), LrC

These chaotic, yet beautifully entangled filaments of shocked, glowing gas span across planet Earth's sky like the tail of a kite.  Located in the constellation of Cygnus as part of a larger cloud complex commonly known as the Veil Nebula, the cloud complex is a large supernova remnant (SNR), an expanding cloud born from the death explosion of a massive star.  Light from the original supernova likely first reached Earth over 5,000 years ago.

This piece of the larger cloud is most frequently identified as "Pickering's Triangle", so named for a former director of the Harvard College Observatory (HCO); but, it is perhaps better named for its actual 1904 discoverer, Scottish astronomer Williamina Fleming, as "Fleming's Triangular Wisp".  At the time of her discovery, she was an under-study of Dr. Pickering's at the HCO.

The Veil complex in its entirety makes up the visible portions of the Cygnus Loop, several parts of which have acquired their own individual names and catalogue identifiers.  The source supernova was a star 20 times more massive than our Sun.  At the time of explosion, it would have appeared brighter than Venus in the sky and been visible in daytime.  The SNR has since expanded to cover an area of the sky roughly 3 arc-degrees in diameter (or about 6 times the diameter of our full Moon).

The glowing filaments are really more like long ripples in a sheet seen almost edge on, remarkably well separated into the familiar red glow of ionized hydrogen atoms, and ionized oxygen in blue.  Also known as the Cygnus Loop and cataloged as NGC 6979.  Given its estimated distance of appx 2,400 light years, the length of the wisp is about 30 light years. 

The framing of this image makes only the "Wisp" portion of the overall 'Loop' complex visible.   In modern usage, the names Veil Nebula, and Cygnus Loop generally refer to all the visible structure of the entire nova remnant.  Another image in this collection, "211105 - C33 Eastern "Veil" nebula" shows an eastern portion.  The image "240715 - C34 Western "Veil" nebula" shows a western portion, and "230522 - Cygnus Loop Cloud Complex" shows the entire SNR.

241007 - "Fleming's Wisp" nebula