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MESSAGE OF THE MONTH
Passing a planet
If someone manages to capture a picture of the Internatioinal Space Station (ISS) crossing the Sun or the Moon, that is no small feat, but what about getting it crossing a planet? I would like to share my image that I took of the ISS transiting Jupiter, which was a difficult shot!
I discovered that, on 15 January, the ISS crossing Jupiter would be visible along a line that passed just 4km from my home. I drove to the location of the centreline and checked I was in the right place with my GPS. But the view was blocked by trees and I had to move my mount by 3m to a clear spot where Jupiter would be visible.
The weather was predicted to be cloudy by either 40 per cent or 5 per cent. Thankfully, it was the latter and the sky around the gas giant was clear! So I set up my mount, an iOptron CEM25P; my telescope, a Celestron C90; and the camera, a ZWO ASI290MM mono CMOS model; and connected it all to the computer for some test runs. Then I waited for when the transit was predicted, at 7:08pm local time, and began a 90-second video. When I checked the video, it turned out that out of a total of about 25,000 frames the ISS only appeared in 150!
René Saade, Cozumel, Mexico
What a fantastic feat to have captured such a fine alignment as the ISS and Jupiter, René, well done!
This month’s top prize: two Philip’s titles
The ‘Message of the Month’ writer will receive a bundle of two top titles courtesy of astronomy publisher Philip’s: Nigel Henbest’s Stargazing 2022 and Robin Scagell’s Guide to the Northern Constellations
Winner’s details will be passed on to Octopus Publishing to fulfil the prize
Seeing violet
A violet flash is a rare optical phenomenon, especially when it is observed at sea level. Abnormal heat conditions on the Mediterranean Sea can help to create atmospheric conditions, even at low altitudes, which make it possible to admire this optical effect.
It happens because green and blue light is refracted more red and orange light, and the result is a phase shift between the various colours of light. On the horizon, first the red disappears, then the yellow, and then the green. The last component is the blue ray, which is the most difficult to capture.
Salvatore Cerruto, Marina di Modica, Sicily
Lucky strike
This is a photo I took of a meteor that was reported on 29 January at 6:48pm from Grassholme Observatory. There was a rumour that there could be an aurora display that night and I thought I would set my camera up for some timelapse photography in the hope of capturing it. I positioned my setup to face north northeast and selected a continuous firing settting for the shutter. The fireball shot was six seconds long.
Andrew Morl, via email
Pulsar speed
In the article ‘Looking Back’ (Inside The Sky at Night, February 2022 issue, p19) it is stated that the fastest pulsar flashes every 1.39 milliseconds. This is attributed to the pulsar rotating on its axis. If the pulsar had the same circumference as Earth (40,000km) this would mean that its equatorial peripheral velocity would be about 100 times the speed of light!
Clearly this cannot be so, meaning that its circumference would have to be less than 400km. Alternatively, perhaps it is not the body of the pulsar that is rotating, but its magnetic field: I wonder whether or not the true situation is known.
William Roberts, Rothwell, Northants
Neutron stars are so dense that their typical mass, around 1.5 times that of the Sun, is compressed into a sphere with a circumference of only around 100km. This means that the pulsar with the fastest spin travels at 24 per cent the speed of light at its equator, more than 70,000km/s! – Ed.
On the rise
I recently took two images of the Moon with my phone (above), taken five seconds apart in Cumbria. The object close to the Moon in the first shot seems to have moved upwards in the second. Do you have any ideas what it is?
Gary Frazer, via email
The object that has moved upwards in the second photo (right) is a lens flare, caused by the bright moonlight being scattered by the phone camera’s lens. – Ed.
True blueshift
I was reading about redshift and ‘blueshift’ was also mentioned, implying that objects were coming towards us. Are there objects that display this?
Mike Bailey, via email
Yes, Mike, light from the Andromeda Galaxy is blueshifted as it is moving towards our own Galaxy. And nearby stars like Barnard’s Star are moving toward us, resulting in a small blueshift as well. – Ed.
Tweet
Paul Macklin @MathCancer • Feb 20
I’ve finally officially published my #Messier82 photo. I processed this starburst galaxy, with 7 hours of wideband and 9 hours of Ha data, in this HaRGB image using a @zwoasi #asi533mc and 8-inch scope. @AstroBackyard @ skyatnightmag @AstroHour321
On Facebook
WE ASKED: Where is your favourite place to stargaze?
Emma Hugo My favourite place is my local tor, named Helman Tor. It’s a lovely Cornish granite hill with not much surrounding light pollution. A short walk from the car park will have you on a fairly flat grass surface, which is great for getting your gear set up. Lanivet amateur astronomy group have had meet-ups here to watch the sunset.
Carol Miller Cornwall’s Helman Tor is near where I live and the views are stunning, especially on the summer solstice, watching the sunset and the darkening sky.
Gary Chittick Clyde Muirshiel Regional Park, Renfrewshire. This is our darkest local area, which is terrific for viewing the night sky, meteor showers, aurora displays, the odd comet and plenty more.
Luca Parmeggiani Verdon valley in southern France.
David Millar Drumroamin Campsite, the site of the Galloway Star Camp held twice a year.
Mark Tissington Dalby Forest, North Yorkshire.
david.o.flynn • 21 Feb 2022
A full Moon encircled by each of its phases. It’s been so cloudy that I’m beginning to forget what the sky looks like, so I took the liberty of creating the lunar phases manually rather than using raw data. The compsite is created with a Canon 450D DSLR camera (using EXIF data) and a Sky-Watcher EQ5 200P reflector. I used the best 80% of 667 frames. #youresa #amazingshots_ moon #nightskyphotography #astronomy @bbcskyatnightmag
SOCIETY IN FOCUS
With a population of nearly 2,500, Moffat was the first town community outside the USA to receive dark sky status from the International Dark-Sky Association (IDA).
It was granted in 2016 after an exterior lighting plan was developed by resident James Paterson, a semi-retired lighting professional. All the streetlights were replaced by cut-off LED lighting units, thanks to a Scottish government grant.
To capitalise on the IDA status, the newly founded Moffat Astronomy Club decided to build an observatory for its members and the whole community. Support from local people, businesses, the council and Moffat Academy helped to raise funding. The club chose a location with a good view of the horizon and easy access, close to Moffat Academy, and constructed two log cabins, designed by Jim Paterson. Construction was difficult due to adverse weather and was halted during the COVID-19 lockdowns.
But the observatory is now open to the public and offers practical astronomy sessions to Moffat residents, including schoolchildren, at no charge. One cabin houses the dome and a Meade f/8 AFC 16-inch (400mm) telescope, which has a focal lenth of 3,251mm. Two solar panels provide power to two large batteries.
Sessions can be booked via the website and these offer guided tours of the night sky. Tutorials on astrophotography and advanced astronomy are coming soon.
Jim Connechen, Chairman, Moffat Astronomy Club > www.moffatastronomy.com
Scope Doctor
Our equipment specialist, Steve Richards, cures your optical ailments and technical maladies
Email your queries to scopedoctor@skyatnightmagazine.com
I have a Celestron AstroMaster 130EQ that was given to me, but the focus doesn’t seem to wind out far enough. Do you have any tips? SEAN CHESMAN
Supplied new, this Newtonian reflector doesn’t require any additional spacing between the eyepiece holder and the eyepiece to achieve focus, and the focus tube appears to be extending correctly as designed. The fault most likely lies with the position of the primary mirror in relation to the secondary mirror.
As this telescope was donated, you won’t know its full history, but a common modification to achieve focus when using a camera is to move the primary image up the optical tube towards the secondary mirror. This adjustment results in the focused image appearing further out from the optical tube than normal. I suspect that this might be what has happened to your telescope.
There are two solutions to this issue, the first being to move the primary mirror back to its original position, but it would be much easier to purchase a simple 1.25-inch extension tube like the Orion 5123 or Svbony SV157 and place this in between the eyepiece holder and the eyepiece.
Steve’s top tip
What are baffles?
When light passes through a telescope there is always the propensity for some of it to be scattered by reflection from components inside the optical tube, resulting in a loss of contrast. Much of this scattered light can be removed by the inclusion of baffles within the tube. These baffles comprise thin, plastic or metal, matt black rings affixed to the inside of the tube with an inner diameter that only allows the cone of light from the primary lens or mirror to pass through to the eyepiece. Stray light is absorbed by the baffles increasing contrast and allowing dimmer objects to be observed.
Steve Richards is a keen astro imager and an astronomy equipment expert.