August 2020

NGC 6804 - September 2020 Visual Challenge Object

Original article appears in GuideStar September, 2020.

NGC6804.png

By Stephen Jones

NGC-6804 Planetary Nebula in Aquila

RA 19h31m35.2s Dec +09deg 13’31”

Size 35” Vmag 12

NGC 6804 was discovered in 1791 by the great William Herschel, though he logged it as a cluster for some obscure reason (possibly faint stars around the periphery reminding him of a globular?).  It is of similar size to our July object, the Turtle Nebula in Hercules, though it is noticeably fainter.  It should still be easily visible in medium-sized telescopes.  My personal log of this object is from the 2015 HAS picnic using the 12.5” f/7 reflector that used to be housed in the HAS Observatory at the Dark Site (since been replaced by the 12” RC).  In the f/7 at 314x I noted, “Oval; central star visible with direct vision; star to the side of the nebula is brighter; annular; strong response to OIII filter.”  Photographs of the object indicate a two-shelled structure, though I did not see this with the 12.5” on that occasion.  Reports on the internet indicate that from good skies NGC 6804 is at least visible in as small as a 4” telescope.  This object is on the Astronomical League’s Planetary Nebula program object list.  If you enjoy this object, that list may be a good observing project for you.

Messier Objects for September 2020

Original article appears in GuideStar September, 2020.

M17 M18 M23.pngThis is a series of columns primarily revolving around observing the Messier Catalogue.  The intent is to provide the reader a sampling of the Messier objects each month that are most visible in the time frame the column is published.  Hence, these deep sky objects should be easily identifiable in and around the month of September.  Some months may have a special treat in addition to the Messier Objects.  Check the trailer. 

 

M23: Open Cluster

The Sagittarius Milky Way contains so many notable objects that it is easy to overlook some of the smaller treats.  M23, for example, all but hides in the southwest corner of a dark and inconspicuous valley that slices through the hub of our Galaxy.  Yet this open cluster of 150 or more stars spreads across 15 light years and is deceivingly dynamic.

The loneliness of M24 and its dark surroundings is somewhat intriguing.  The cluster is intermediate in age at around 300 million years old.  Surveys have found 30 variable stars ranging in magnitudes from 10 to 17. Seven of the stars are eclipsing binaries including two apparent W UMa contact binaries and one eclipsing binary.  The remaining 23 variables are likely semi-regular variable stars.

Messier notes: (Observed June 20, 1764) Star cluster between the tip of the bow of Sagittarius and the right foot of Ophiuchus very close to the star Flamsteed 65 Ophiuchi. The stars in this cluster are very close together.  

NGC note: Cluster, bright, very large, pretty rich, little compressed, stars of 10 magnitude or greater.

               

Messier 23 M23 – NGC 6494
Constellation:  Sagittarius  Magnitude: 5.5
Sky Coords: RA: 17h 56.9m   Dec: -19.01 Dist: 2,000 ly+-

 

Summer Triangle Corner: Altair

Original article appears in GuideStar September, 2020.

NSN.pngThis article is distributed by NASA Night Sky Network

The Night Sky Network program supports astronomy clubs across the USA dedicated to astronomy outreach. Visit nightsky.jpl.nasa.gov to find local clubs, events, and more!

by David Prosper

 

Altair is the final stop on our trip around the Summer Triangle! The last star in the asterism to rise for Northern Hemisphere observers before summer begins, brilliant Altair is high overhead at sunset at the end of the season in September. Altair might be the most unusual of the three stars of the Triangle, due to its great speed: this star spins so rapidly that it appears “squished.”

Asterisms – Kemble’s Cascade, Kemble 1

Original article appears in GuideStar September, 2020.

by Steve Goldberg     Originally published in the October 2017 Guidestar

Asterism: a grouping of stars that form a recognizable pattern.
Camelopardalis.PNGConstellation: Camelopardalis
Right Ascension: R.A.: 03h 57m 04.0s
Declination: +63° 04' 00"
Magnitude:  5 to 10
Size: 2° 30” 
Found in the constellation Camelopardalis is a line of about 20 stars in a straight line that ends at NGC 1502, an open cluster.
Finding the constellation will be a challenge since there are no bright stars. Look for Polaris, Capella and the constellation Perseus. Camelopardalis is between those, as shown at right.

Letter from the President - September 2020

Original article appears in GuideStar September, 2020.

HAS_New Member Orientation_v2.jpgAs I mentioned in an earlier newsletter, one of the things I wanted to focus on in 2020 was increasing our member engagement.  We have taken a look at where and how we engage our members from before the time a potential member engages us, then into the actual process of joining us, and into how we educate them on what it is the club has to offer them.  From there, it’s a matter of continual engagement through our club activities and programs.  Needless to say, COVID-19 has thrown us for a loop with some of these things, but we’ve been able to adapt pretty well and find new ways continue this engagement forward.

One of the things we’ve done recently is to come up with a New Member Orientation class that we piloted in August for the first time.  Roughly 40 new members have attended one of these sessions in August. The purpose of this orientation session is to help familiarize new members, as well as members who might not have been as active with the club recently, with all of the things that our club has to offer.  We start off with the history of the Houston Astronomical Society and let people know who the current leaders of the club are, and how to stay connected to the club through various technology avenues.  We then dive into all of the great programs, activities, and benefits that they can take advantage of as club members.  Some of the more popular areas that get a lot of interest from the people in this orientation class are details about the dark site and benefits like the Loaner Telescope program.  It’s incredible to see just how many new members attend the orientation and then go out to the dark site or submit a request to borrow one of the club telescopes.

It’s my hope that as many of our new members can attend these classes to learn about all it is the club has to offer them.  While COVID-19 has put a damper on a lot of the things we did in our day-to-day lives before the pandemic, astronomy is an activity that has seen more people get involved in.  Joining the Houston Astronomical Society and attending the New Member Orientation are some of those first steps in what we hope is a lifelong journey into this hobby.

Look for one of these orientation sessions soon, and if you haven’t had a chance to attend one yet, please consider joining us soon!

Shallow Sky Object of the Month: HD 162826

Original article appears in GuideStar September, 2020.

HD 162826

by Bill Pellerin

Previously Published in the September 2014 Guidestar (Bill Pellerin – Editor and HAS President)

Object: HD 162826 Class: Star
Constellation: Hercules
Magnitude: 6.5
R.A.: 17 h 51 m 14 s
Dec: 40 deg 04 min 21 sec
Size/Spectral: 1.15 solar mass, F8V
Distance: 110 ly
Optics needed: Binoculars or small telescope

 

Why this object is interesting:

We all know that stars are ‘born’ in clusters. The evidence of that is easy to find. The Pleiades is a cluster of relatively young stars which have yet to completely shed their cocoon of dust and gas. The Orion Nebula is an example of stars in an earlier stage of development, still enshrouded with the dust and gas that is forming the stars.

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