Saturday, March 1, 2014

Sunspots

Sunspots are fascinating if you know how to watch and study them. Fortunately, you can observe and photograph sunspots safely with simple equipment and affordable accessories.

What are sunspots?
Sunspots are cooler areas on the sun surface. They are not really cool, just 500-600 degrees cooler than their environment. Sunspots emit less radiation and this is the reason why they look black on the surface of the sun. The sunspots by themselves are still many times brighter than the full moon. The reason why and when sunspots are formed on the sun is not clear yet but it is related to high electromagnetic energy activity. Sunspot regions are very active and can send strong CME (Coronal Mass Ejection) to space. If such CME is in the direction of earth, there might be noticeable events such as the polar auroras and interferences to the electricity network.

Every observation of the sun requires special  protecting equipment. Direct watching of the sun is very dangerous and can lead to blindness. Do not use old films, black glasses and their like. Only dedicated protecting filters are allowed. The writer takes no responsibility for any viewing of the sun.

History of sunspot observations
The first person to observe sunspots was Galileo Galilee. Although it is possible to see large sunspots with the naked eye during sunsets, we have no documentation of anyone in the ancient times noticing them. Galileo looked through his telescope (and without giving proper notice to the safety guidelines, thus becoming blind at the end of his life) and saw the spots. The previously perfect sun became imperfect which was another low to the old Greek opinion that all celestial orbs are perfect. Galileo noticed that each day the spots look a bit different and also that they are moving on the sun. In a long series of drawings from 1613 he proved and demonstrated that the sun revolves around its axis. Here is an example of Galileo's drawings, you can see many more drawing in the Galileo project site.  

Galileo's drawing of sunspots 1613
Galileo's drawing of sunspots 1613


Observing sunspots  with solar eclipse glasses
The most basic equipment are solar eclipse glasses. These glasses have a little solar filter film and it is safe to watch the sun with them. However most sunspots are too small and only big spots will be seen. Seeing the spots requires an optical device such as telescope, binoculars or long zoom camera.
Please notice that any solar filter must be in front of the first optical element. It is extremely dangerous to use solar eclipse glasses and then look through binoculars. The filters are not adequate for such use. The binoculars intensify the amount of the radiation and the filter will burn.


Creating a homemade solar filter
To view the sunspots through an optical device, a solar filter is required. A glass filter can be quite expensive, but there is a way to create a filter very easily. You need to buy a proper solar filter sheet (A4 size or whatever suits your need). You can make many filters from a single sheet for your camera, binoculars and so on. Looking through the filter you will see nothing except for very hot objects such as a tungsten light bulb.
Today there a DSLR-alike camera with 24x 30x or even 50x zoom lens which are very good for simple astro-photography. You can cut a square piece of kappa foam, make a circular hole in the diameter of your lens and stick a filter all over it. This will give you a proper solar filter. Make sure that the filter is firmly attached to the camera or binoculars and can't fall from it before use.
You will also need a tripod. Small cameras are not heavy and even a simple tripod will be good enough for most purposes.

Tungsten wire through solar filter
Tungsten wire through solar filter
I am using a Canon PowerShot SX50 HS for sunspots photography. It is a small and affordable DSLR like camera with 50x zoom (1200mm equivalent). The camera is not very expensive and this is how it looks with the solar filter attached.

The camera with the dedicated sun filter
The camera with the dedicated sun filter

Some more safety rules
When observing the sun with such filter observe the following rules.
  • Always make sure that the filter is attached firmly. 
  • Make sure that no one tries to touch or check the filter.
  • If you have to leave the area, do not keep the telescope aimed at the sun. Aim it the ground and cover the lens with the plastic cap. 
  • Check that the filter is not scratched or torn before each use.

How to photograph sunspots
Photographing the spots is simple:
  • Put the filter on the camera and aim to the sun. 
  • Use the maximum zoom that the camera has (20x and up) but do not use digital zoom.
  • Set the camera focus to manual at infinity
  • Set camera ISO to value between 100 and 400. 
  • Use the largest aperture possible to enable a shorter shutter speed. 
  • Use a tripod even at faster shutter speed. 
  • Set the light-meter to spot mode. Most of the frame is completely dark and average light metering will yield wrong results.
  • Experiment with the shutter release setting. Usually a little overexposure (+2/3) will improve the photo
  • Use a delay to eliminate "camera shakes" from pressing the camera button
The best hour for sunspots photography is around local noon. The sun is at its highest point in the sky and that can improve the quality of the photo. Due to the Earth rotating around its axis, the spots will change their place in the sun disc during the day. To see this just take photographs at the morning, noon and evening of the same day.
However the spots has a real movement on the sun disc, since the sun revolves around its axis once in 25-35 days. The sun is made of gas so its rotation speed is not the same in different latitudes. The slowest rotation is around the poles and the fastest around the equator. For this reason if you take a photo on the same hour for several consecutive days you will see the movement of the spots as the sun rotate. Try to compare your photos to professional photos such as in the Space-weather site.
Viewing and photographing sunspots is great fun for me. When there are large spots I usually take solar eclipse glasses and show other people what's happening on the sun. Many people, old and young are interested to see the sunspots.

Here are several photos from consecutive dates (almost). I tried to rotate the photos so they will be in the same alignment. The movement of the spots is clear. The sun is very dynamic. New spots are forming, old spots are decaying, and no day is the same. Even without dedicated solar scope, one can see the changing face of the sun.

Sunspots  14/02/2014
Sunspots 14/02/2014
The spots start to disappear behind the sun limb
Sunspots  16/02/2014
Sunspots  16/02/2014

Sunspots  17/02/2014
Sunspots  17/02/2014
 Most sunspots disappeared but other are coming out from the left
Sunspots  18/02/2014
Sunspots  18/02/2014

Sunspots  20/02/2014
Sunspots  20/02/2014


Wednesday, February 26, 2014

Moon Venus conjunction

What a marvelous moon Venus conjunction! The early bird gets the best photos. The moon rose at 3:30 and Venus just 7 minutes after it. I got up at 4:40am to see this marvelous view from my roof. I am using a Canon HS50 for this photos. It is a simple camera and very affordable with a huge x50 zoom which looks like a telescope. No telescope is required.
Since the moon moves quite fast, Venus is already in the same height as the moon, and in few hours Venus will be above the moon.
It will be possible to see both during he daylight hours as well, check the article about how to see Venus in daylight. Also notice the gibbous shape of Venus which has phases just like the moon.

Moon and Venus conjunction
Moon and Venus conjunction
About one hour later, already dawn the moon is even nearer. See the difference in this photo
Moon and Venus conjunction
Moon and Venus conjunction

And another one shortly after with much more daylight
Moon and Venus conjunction
Moon and Venus conjunction


Also in the early hours sky are Mars in Virgo and Saturn in Libra. We are at the end of the Winter and the entire Summer Triangle of Vega, Deneb and Al-tair is already up

The summer Triangle. Vega (up) Deneb (Left) and Altair (Right)
The summer Triangle. Vega (up) Deneb (Left) and Altair (Right)
And a scene photo in wide area with all the morning clouds. The tiny dot just above the moon is not dust, it is Venus!
Moon and Venus conjunction
Moon and Venus conjunction

Great naked eye observations!


Monday, February 3, 2014

Astro photos are easy

Astro-photography doesn't require expensive equipment. These photos all taken in a single day using an OLD Sony alpha DSLR (The ISS pass) and a relatively new Canon HS50 which has a great zoom. The only really must equipment is a sturdy tripod which will enable you to stable the camera for long star exposures.

 The sunspots photo requires a solar filter, and it is dangerous not to use one. Here is a detailed article about how to photograph sunspots

This huge sunspot is AR1967, and I am following it for many days. On February 3 2014 it was almost in the middle of the sun

Sunspot AR1967
Sunspot AR1967
 The next photos are from the sunset and the sunspots are seen easily
Sunspot AR1967 during sunset
Sunspot AR1967 during sunset
The perfect round is a swanning ball on a high voltage power line, but it remind me the great Venus transit from two years ago.
Sunspot AR1967 during sunset
Sunspot AR1967 during sunset

Sunspot AR1967 during sunset
Sunspot AR1967 during sunset

Sunspot AR1967 during sunset
Sunspot AR1967 during sunset
The next photo is a great ISS pass in the well known constellation Canis Major (Great dog). The pass was very low and the light pollution is visible. however the entire group is visible and in the full photo I was able to detect the open cluster M41. Also I caught the extinction of the pass and you can clearly see the graduate extinction in the pass color from white to red.
ISS pass in Canis Major
ISS pass in Canis Major

Even f your camera doesn't have much zoom power to get good photos of the moon or the sun, you can still get nice photos of the constellations. You will need to experiment but even 1 second of exposure will show many stars. If you are in a rural area you can take longer exposures. Be aware that the longer the exposure time, the stars will create small trails as the Earth keep rotating around its axis. Also notice that it might be hard to see stars on the camera small LCD and you might need the help of a laptop to compose the photo. Also try to use manual focus and set it to infinity.
Here is Orion Constellation
Orion Constellation
Orion Constellation
And Orion constellation with the ISS. This is a 20sec shot and the light pollution is clearly visible.

The ISS in Orion
The ISS in Orion
And finally the moon
The moon
The moon
Conclusions: Even with simple equipment there is plenty to do! Good luck

Sunday, February 2, 2014

Carnival of Space #339

Hi all and welcome aboard the 339th edition of Carnival of Space. We will start this edition by honoring the 17 astronauts who have given their life to the American space program. On January 27 1967 during a training for the first Apollo mission, less than a month before the planned launch, a fire in the crew cabin took the life of  Virgil I. "Gus" Grissom, Edward H. White and Roger B. Chaffee. The challenger disaster occurred on January 28 1986 just 73 seconds after launch, taking the lives of Francis R. Scobee, Michael J. Smith, Ronald McNair, Ellison Onizuka, Judith Resnik, Greg Jarvis and Christa McAuliffe. On February 1 2003 the Columbia disaster at the end of STS-107 mission, and in which Rick D. Husband, William C. McCool, Michael P. Anderson, Kalpana Chawla, David M. Brown, Laurel Clark and the Israeli astronaut Ilan Ramon died.
Dedicate a few moments in memory of these men and women in the official NASA day of  remembrance page.

Apollo 1, Challenger and Columbia Astronauts. Credit: NASA


Back again to this week articles. We will start with our closest neighbor, the moon.
Dr. Paul Spudis shares his memories and knowledge as one of the investigators and researchers in Clementine missions. A comprehensive article about the mission can be found in Dr Spudis's blog. A summarized version can be found in Air&Space magazine.

The next item from CosmoQuest shows that even spaceships, orbiters, landers and such like to have some company from time to time. Read about the latest spacecraft imaging  another spacecraft, LRO take a snap of LADEE.

Another useful article from CosmoQuest. What are some great mobile apps for doing and learning astronomy? Here's a list with a link to our recent Hangout on the subject. I already downloaded few of these great apps.

The Synergy principal is true everywhere and also in space - three are better than one. The Urban Astronomer tells us about the Frontier Fields program - an ambitious attempt to combine the power of NASA's three flagship space telescopes (Hubble, Chandra and Spitzer) to peer deeper into the universe than ever before and learn about the structure of the first galaxies to form after the Big Bang.

From Discovery News we learn about vast rivers of Hydrogen flow into galaxies.

What's new on Mars? Meridian Journal discuss two new photographs from Curiosity: Dingo Gap and the ‘Firepit’.

The last three articles are from NextBigFuture: Elon Musk thinks there are five innovations that will change our lives in the decades ahead:

  • The Internet, an astonishing invention by which people can access knowledge from anywhere.
  • The transition to the sustainable production and consumption of energy.
  • The extension of human life to other planets, depending on how rapidly we progress in developing space transport and how we live - if we manage to survive -- by then.
  • Reading and writing genetic code
  • AI - artificial intelligence.
Make yourself some free time and watch the videos of Elon Musk.

The discovery of water on Ceres arise many more plausible places for astrobiology research: Unlocking the solar system by unlocking water in the asteroids.


And back to the moon on a future missions to find exact location of water on the moon during 2018.

That's all for this, thank to all our contributors and readers. As always hosting the CoS is a pleasure.