Archive for June 11, 2020

Messier 8: Nebula and Cluster in Sagittarius – July 2020 Observer’s Challenge Report #138

June 11, 2020

MONTHLY OBSERVER’S CHALLENGE

Compiled by:

Roger Ivester, North Carolina

&

Sue French, New York

July 2020

Report #138

Messier 8, Nebula and Cluster in Sagittarius

Sharing Observations and Bringing Amateur Astronomers Together

Introduction

The purpose of the Observer’s Challenge is to encourage the pursuit of visual observing. It’s open to everyone who’s interested, and if you’re able to contribute notes, and/or drawings, we’ll be happy to include them in our monthly summary. Visual astronomy depends on what’s seen through the eyepiece. Not only does it satisfy an innate curiosity, but it allows the visual observer to discover the beauty and the wonderment of the night sky. Before photography, all observations depended on what astronomers saw in the eyepiece, and how they recorded their observations. This was done through notes and drawings, and that’s the tradition we’re stressing in the Observer’s Challenge. And for folks with an interest in astrophotography, your digital images and notes are just as welcome. The hope is that you’ll read through these reports and become inspired to take more time at the eyepiece, study each object, and look for those subtle details that you might never have noticed before.

This month’s target:  

Messier 8 is made up a historically confusing collection of star groups and nebulosity. According to expert NGC/IC researcher Dr. Harold Corwin: “NGC 6523 is the star-forming core of M8 at the heart of the bright northwestern part of the nebula. NGC 6526 is the southeastern part of the nebula, and NGC 6530 is the bright star cluster 10-12 arcmin following N6523.  NGC 6533 applies to the entire M 8 complex, and IC 1271 and IC 4678 apply to condensations in its eastern reaches.”

You can read more about these and many other items of interest at: http://www.haroldcorwin.net/ngcic/ngcnotes.all and http://www.haroldcorwin.net/ngcic/icnotes.all 

 2019 and 2020 journal papers involving parts of the M8 complex use distances from 4.1 to 4.3 thousand light-years.  

 

Sue French:  Observer from New York

I’ve sketched M8 on two occasions. I worked on my first sketch during two nights in 1997 with my 105mm (4.1-inch) refractor at 87×. I did not use a star diagonal, so this drawing has north up and east to the right. My sketch paper back then left something to be desired. It took penciling very well, but was a bit yellowish and tended to look rumpled.

IMG_1666

The second sketch was made in 2016 as seen through my130mm (5.1-inch) refractor at 48×, also on two nights. A narrowband (UHC) filter was used to help define the nebula, but no filter was used for the stars. The brightest star on the right-hand side of the sketch is 7 Sgr, which looked yellow through the scope. In this mirror-reversed view north is up and west is to the right. The small, butterfly-shaped region in the brightest part of the nebula is known as the Hourglass.

IMG_1665

 

Mario Motta:  Observer from Massachusetts

For M8 it is large for my 32-inch, so I am sending two sets of images:  The first image is from my 32-inch which shows the center of the lagoon, and also highlights the star forming glow to the right of the lagoon itself, and the hourglass shape glow. 

This image taken with narrowband imaging Ha, O3, and S2, total about three hours.  Also Ha only as it shows detail, 1.5 hours

Next image an M8 wide field, taken with my 8-inch RC which was piggybacked on my scope. 

This is Lum, R,G,B filters, and also some Ha added to Lum and Red.  This is a total of about 3.5 hours imaging.    James Dire

M8

 

M8-W-colorA

 

Uwe Glahn:  Observer from Germany  

Objekt: Messier 8 “Lagunennebel”

Teleskop: 4″ Bino

Vergrößerung: 55x

Filter: [OIII]

Bedingungen: fst 6m5+

Seeing: III

Ort: Sudelfeld

M8 Uwe

 

 James Dire:  Observer from Illinois  (Telescope, camera, write-up later)

M8