Astronomy Cafe – May 16, 2022

Posted by as Astro Cafe

Video transcript of meeting

  • Special General Meeting for RASC Victoria Centre – Randy Enkin
    • Have a quorum of over 25 Victoria Centre members in attendance
    • Changes to ensure our bylaws are consistent with the national bylaws and BC Society’s Act requirements
    • Call for volunteers to work on more revisions to Victoria Centre bylaws over the next few months
  • Need volunteers for Astronomy Cafe – contact Randy Enkin
    • Zoom host – recording and posting the video transcripts online
    • Meeting host – tracks and runs the meetings
  • Star parties at Observatory Hill – Lauri Roche
    • May 21, Jun 4, 18 – hybrid party in-person and online on Zoom & Youtube
      • May 21 – Early Discoveries made by the Plaskett Telescope – Jim Nemec
    • Every Saturday night after the July 1st break for the summer
    • Volunteers needed: telescopes in the parking lot, RASC welcome table, Plaskett dome tour hosts, 16″ telescope operators, other roles – contact Lauri
    • Electronically-Assisted Astronomy – start planning to use at the Star Parties in future – contact Dave Lee
  • Nanaimo Astronomy – Janeane MacGillivray
    • Astronomy From Kitt Peak – David Lee presenting at upcoming meeting
    • RASC Victoria members are welcome – send an email
  • Total Lunar Eclipse reports from members – May 15/16, 2022
    • Cloudy photos from Saanich after being skunked at Cattle Point – David Lee
    • HDR smartphone photos through eyepiece, join observations from Cosmic Generation group – Nathan Hellmen-Mestleman
    • Lunar Crater transits & mare cookies – Randy Enkin
    • Cloudy photos from Sidney – Chris Gainor
    • Observed from Brentwood Bay while raining – Lauri Roche
    • Just a glimpse from Taylor Beach in Metchosin, but spotted ISS – Bill Weir
  • Plaskett Images – Dan Posey
    • Composite image of the images over last few years 
    • Whirlpool Galaxy, Whale Galaxy, Deer Link Group NGC 7331, Fireworks Galaxy NGC 6946, M100, M63 Blackeye, NGC 3718 Arp galaxy, Hickson 44
    • Plaskett nights are for enjoyment and a reward for RASC Victoria members and volunteers
    • Review of techniques to process Plaskett image data into nice images
  • Skynews magazine – Bruce Lane
    • Review of upcoming articles
    • Please send Total Lunar Eclipse observing reports to Bruce (Editor)
  • Black Holes – Randy Enkin
    • M87 Black Hole – April 22, 2019 – Event Horizon Telescope
    • Sagittarius A* Supermassive Black Hole – May 16, 2022 – BBC Science Focus article
    • Galactic nucleus observed by Karl Jansky in 1931 – published in Nature, 173, 985-987, 1954
    • Angular resolution problem solved by the Event Horizon Telescope
    • Motion analysis of objects and energy near the Event Horizon of a black hole
    • Lauri Roche’s “black hole” birthday gift

Total Lunar Eclipse – May 15/16, 2022

Posted by as Observing Highlights

On Sunday, May 15th, 2022, we will be able to view a total eclipse of the Moon (weather permitting) from Southern Vancouver Island, British Columbia, Canada. The Moon will be in full eclipse after rising from the southeastern horizon, remaining fully eclipsed for about an hour before transitioning into a partial phase as it climbs in altitude and moves to the south. The Lunar Eclipse will end just before midnight.

Enlarge this video to view details for the Lunar Eclipse timing and phases. Depiction of this particular Lunar Eclipse is as viewed from Victoria – generated by Starry Night Pro Plus 8 and captured using Snagit 2022.

This is a perfect opportunity to visually observe this beautiful celestial event, and possibly capture some photographs from a location with an unobstructed view to the east and south.

Total Eclipse Begins8:29PM
Moon Rises8:42PM – probably visible 10-15 mins later
Greatest Eclipse9:12PM
Total Eclipse Ends9:54PM
Partial Eclipse Ends11:51PM
Above Eclipse times are for Pacific Daylight Time (PDT) for the west coast of North America, and are calculated from UT as presented in the Observers Handbook 2022, pages 127-131.
Lunar Eclipse diagram – NASA

What’s Happening

A total lunar eclipse occurs when the Earth comes between the Sun and the Moon. During a lunar eclipse the Moon’s position traverses the Earth’s shadow. The Moon’s first contact with the Earth’s shadow is at the outer band of the shadow called the penumbra. The light falling on the Moon is progressively blocked until at the moment of total eclipse the Moon is completely in the darkest central area of the Earth’s shadow called the umbra. At the point of total eclipse the process starts to reverse itself until the Moon is totally out of the Earth’s shadow.


Glossary

  • limb – the outer edge of the Moon
  • penumbra – the outer band of the Earth’s shadow
  • umbra – the darker central area of the Earth’s shadow
  • partial eclipse – the Moon is positioned within the penumbra
  • total eclipse – the Moon is positioned totally within the umbra

Observing Tips

What do you need?

Everything from your eyes, binoculars and telescope are suitable. Bear in mind this is a long process, so dress warmly and bring a chair if you want to be comfortable.

Find yourself a location that has a clear horizon view to the east and south especially if you wish to view the early fully-eclipsed stage. Observing from a hill will help you spot the rising Moon earlier than if you observe from lower elevations or sea level.

Keep a log of what you see and note the time. Pay attention to how much of the light on the moon is obscured and if there are any colouration changes. During the total eclipse the Moon will take on a deep orange-red colour. The colour of the Moon is a function of contaminants in the atmosphere and varies from year to year.

A good observing project for this long-lasting eclipse will be to observe the craters on the Moon as the eclipse progresses. Craters will be immersed and emerge from the Earth’s shadow on the Moon at times specified in the Observers Handbook 2022, page 131.

2019 Total Lunar Eclipse from Victoria – composite photo by Joe Carr

Photographic Tips

Equipment

Any camera with the capability of setting shutter speeds and aperture settings manually will do fine. The ability to use interchangeable lenses will be an advantage for more detailed images of the Moon. For the darker parts of the eclipse, eg. totality you should use a tripod support for best results. If you have access to a telescope you can try capturing the event using prime focus techniques through the telescope optics.

Settings

Today’s digital cameras are very sensitive to light reflected by the Moon. Use ISO 400 to ISO 800 and a long telephoto lens or zoom setting. Smartphones and point-and-shoot digital cameras will not produce rewarding photos of the eclipsed Moon, but can be useful for taking panoramic shots of your surroundings which include the eclipsed Moon.

Technique for smartphone cameras

Smartphone cameras typically do not support manual settings, so using them to capture a lunar eclipse will be less rewarding than using more capable cameras. That said, smartphone cameras can be held up to a telescope eyepiece to capture an image of the Moon. Aligning the tiny lens to the eyepiece can be tricky, however there are platforms made to clamp onto an eyepiece barrel which will hold smartphones steady enough to take acceptable photos of the Moon, including the eclipsed Moon.

Technique for interchangeable lens cameras

The simplest eclipse pictures can be taken with manual settings on your camera and a normal lens, preferably supported by a tripod. For best results use a cable release to minimize vibration. Images taken in this fashion result in a small lunar image. This is why it is preferable to use a telephoto lens to photograph the Moon.

For a full frame camera try a 200mm lens or even better, a 500mm lens or higher. You may also use teleconverters to increase magnification, these typically come in 1.4x and 2x strengths. Their downside is they reduce the effective aperture of your optical system. A 1.4x teleconverter will decrease your effective exposure by 1 stop, a 2x teleconverter will decrease your effective exposure by 2 stops. Work out your effective aperture of your optical system ahead of time so you don’t have to think about it on the night of the eclipse.

Note for the smaller sub-full frame sensors of some digital cameras you gain an extra advantage as the focal length of the lens is effectively magnified by a factor. For example a Nikon DX body your 200mm lens would be effectively 300mm.

  • APS-C Nikon DX, Pentax : 1.5x
  • APS-C Canon EF-S : 1.6x
  • Four Thirds : 2x

Example:

 Focal Length ApertureEffective Focal Length
with 2x teleconvertor
Effective Aperture
with 2x teleconvertor
 180mm 2.8 360mm 5.6
 480mm 6.8 960mm 13.6

To achieve any higher magnification than what is stated above you will have to use a telescope at prime focus. For this your manual camera does need to have the capability of using interchangeable lenses. For prime focus you will use the telescope optics as your interchangeable lens. To attach your camera to your telescope you will need two things a T-adapter that fits your camera and a telescope camera adapter that fits your telescope.

The telescope camera adapter is designed to fit in the focusing tube of your telescope and is threaded to accept the T-adapter of your camera. With the magnification involved with telescopic optics it is likely that you will need to use a tracking mount. Preferably the mount should be able to track at lunar speed as opposed to sidereal but if the shutter speeds chosen are shorter than 1 or 2 minutes this is not critical.

Exposure times are the next consideration. The following exposure times are based on a medium ISO setting and an effective aperture that would be common with a long telephoto and teleconverter combination. Exposures may vary with your equipment based on ISO speed and effective aperture. The Danjon Lunar Eclipse Luminosity Scale has been included to provide better guesstimates for totality.

Exposure Times: based on ISO 400
Full Moon1/500 second at f/16
1st Contact1/250 second at f/16 see note 1.
2nd Contact1 second at f/16 see note 2.
Totality
*see table below
L = 4 : 4 seconds at f16  L = 3: 15 seconds at f16  L = 2: 1 minute at f16  L = 1: 4 minutes at f16
3rd Contact1 second at f/16 see note 2.
4th Contact1/250 second at f/16 see note 1.
* Danjon Lunar Eclipse Luminosity Scale
 L = 1dark eclipse; lunar surface details distinguishable only with difficultly
 L = 2deep red or rust coloured eclipse; central part of the umbra dark but outer rim relatively bright
 L = 3brick-red eclipse; usually with a brighter (frequently yellow) rim to the umbra
 L = 4very bright copper-red or orange eclipse, with a bluish, very bright umbral rim

Note 1. 1st and 4th contact times given for the partial phases are biased for the light part of the Moon. Remember you are dealing with vastly different exposures between the light and dark parts of the Moon during eclipse. The bias of about 1 stop minus avoids overexposure of the dominant bright area of the Moon.

Note 2. 2nd and 3rd contact times given for the partial phases are biased for the dark part of the Moon. The bias of about 1 stop plus is a good strategy for negative film not quite so good for slides and digital capture given they don’t tolerate overexposure well.

The exposure times are only recommendations. Remember the cardinal rule about photography … bracket. Always try exposures plus and minus your chosen exposure. This gives you a better chance at getting usable results. Let’s all hope for clear weather. If you have any questions please send email to David Lee at davidflee7331@gmail.com.


David Lee – original text
Joe Carr – updated for 2022
Brenda Stuart – illustrations


More information:

Astronomy Cafe – May 9, 2022

Posted by as Astro Cafe

Meeting video transcript

  • Astronomy Day thank you’s to volunteers – Lauri Roche & David Lee
    • The in-person interaction was an engaging experience 
    • The younger volunteers were a real delight
    • Sidewalk astronomy from the museum plaza, with very good weather
    • History of Astronomy Day at the Royal BC Museum – Sid Sidhu
    • UVic, Camosun, Victoria High School, Shawnigan Lake School was a good collaboration
    • Galileo Moments
      • Daytime at the RBCM: more than 800 – 231 outside, 654 inside
      • Evening on Observatory Hill: 29 volunteers and more than 100 members of the public
    • A lessons learned meeting with leads – David Lee
    • Publicity worked pretty well – Chris Gainor
    • Hubble history book will be available at Astronomy Cafe next week – Chris Gainor
    • Public lectures – about 40 attendees for each of 4 presentations – Randy Enkin
    • Video recording for lunar observing national feed – David Lee recorded Randy Enkin and Bill Weir
    • Attendance compared with previous Astronomy Days? 
      • Despite a shorter day at RBCM, attendance was very good
      • Previous attendance was between 1,700-2,000 at our bigger events
    • A high quality experience for attendees and children’s activities front-and-centre was a good idea – Jim Hesser
    • Met some interesting people who were very interested in astronomy – Dave Payne
    • Offered to help people to make use of their telescopes – Dave Robinson
    • Astronomy Day – event info and photo gallery
  • M33 Triangulum Galaxy image – Randy Enkin & John McDonald
    • HII star formation region
    • Compared with Barnard’s Loop shock wave (10º)
    • Bubble is the form the shock wave takes caused by multiple stars
    • M33 is a floculant galaxy – clumping of hydrogen material
    • What is a “typical” galaxy? – Dorothy Paul
    • April 2017 Skynews article (PDF) – Orion’s Aura – Orion Eridanis Super Bubble – Reg Dunkley
  • James Webb Space Telescope progress report – Chris Gainor’
    • Image sharpness check completed for all instruments
    • Instrument Modes Check Off – happening next
    • Images will likely start in June or July
    • Diffraction spikes in the images – causes?
    • Difference fields of view for each camera/sensor
  • Special General Meeting at May 16th Astronomy Cafe – Randy Enkin
    • Need a quorum of 25 Victoria Centre members in attendance
    • Changes to ensure our bylaws consistent with the national bylaws
    • Our Secretary Jill Sinkwich is finding several parts of Victoria Centre bylaws that will need to be changed
    • Proposed changes are already sent out to members
  • Need volunteers for Astronomy Cafe – Randy Enkin
    • Zoom host – recording and posting the video transcripts online
    • Meeting host – tracks and runs the meetings
  • Star parties at Observatory Hill – Lauri Roche
    • May 21, Jun 4, 18
    • Every Saturday night after the July 1st break for the summer
    • Volunteers needed: telescopes in the parking lot, RASC welcome table, Plaskett dome tour hosts, 16″ telescope operators, other roles
    • Electronically-Assisted Astronomy – start planning to use at the Star Parties in future – contact Dave Lee
  • National General Assembly – June 24-27 (online) – Lauri Roche
    • Speakers, co-current sessions, virtual field trips
    • AGM
    • Seeking submissions from members to give half hour talks about their passion – submit form by May 15th – contact Lauri

Astronomy Cafe – May 2, 2022

Posted by as Astro Cafe

Video transcript of meeting

  • Intro – Randy Enkin
  • Astronomy Day – David Lee
    • Final check-in this Wednesday evening for leads before Saturday events
    • International Astronomy Day – May 7, 2022
  • Vancouver Island Science Fair intro to awardees – Randy Enkin
  • VI Science Fair: Light At Night – Beata Ariana-Minniti (Cedar Hill Middle School student)
    • Creating a bus stop light using natural resources
    • Parts: Thermoelectric generator, voltage regulator, LED light
    • Heat storage: sand in an insulated box
  • Canada-wide Science Fair: Lower CubeSat orbit could Protect Space Infrastructure – Nathan Hellner-Mestelman
    • CubeSats collide, creating dangerous space debris that orbits the Earth – Kessler Syndrome
    • Quantifying the collisions
    • Lowering the hazard: choosing best orbits, adding micro-thrusters to CubeSats to change orbit or de-orbit
  • Astrophotos from southern Arizona – John McDonald & Garry Sedun
    • Caldwell 30 galaxy
    • M33 Triangulum Galaxy
    • NGC 2903 barred spiral galaxy
    • IC 433 Jellyfish Nebula
  • Eclipse Crater Timing – Randy Enkin
  • James Webb Space Telescope Update – Chris Gainor
    • All onboard instruments are now in focus
    • Commissioning of instruments next, then science projects begin