Spotting the zodiacal light in spring

The zodiacal light is a nocturnal phenomena that is revealed only to those who dare to escape the city lights. In spring, after sunset and once twilight fades away into a dark and moonless night, a gentle luminous band opens up when looking towards west. Its majestic cone then seems to stand high above the horizon, as if it was trying to guide the observer. In fact, the zodiacal light directs us to the very beginning of the solar system, roughly 4.5 billion years ago, when our Earth and the other planets were formed from and within a circumsolar dust disk. Although the solar wind steadily sweeps away dust, new dust grains are formed through outgassing comets and minor planet collisions. Most of these objects orbit the sun in a relatively well defined and narrow plane, which is called the ecliptic, i.e. the plane of the Earth’s orbit. As a result, the ecliptic is continuously fed with fresh dust and gas, which causes the redirection of sun rays through reflection and scattering, which are then captured as zodiacal light by some enthusiasts on Earth. Although zodiacal light can be seen all year round, spring and autumn are best suited for observations from mid latitudes, because then the path of the sun crosses the horizon at a steep angle, making the twilight zone short.

zodiacal light

Zodiacal light observed from Roque de los Muchachos Observatory, La Palma, Canary islands, Spain in April 2016.

Observing Comet C/2013 US10 (Catalina)

Comet C/2013 US10 (Catalina) was first discovered by the Catalina Sky Survey on October 31, 2013. It originates from the Oort cloud, a vast spherical reservoir of comets far beyond Neptun. By chance, gravitational perturbations can push Oort objects into the inner solar system, where they are eventually discovered. In some cases, comets get bright enough to be observed by naked eye or with small amateur telescopes or binoculars. The latter one is true for Comet C/2013 US10 (Catalina).

On Jan. 17, 2016 the comet passed its closest point to Earth at a distance of 110 million km. Using my 10-inch Newtonian telescope, I have imaged the comet that day from a suburban location. The result shown below is a stack of 17 frames of 120 sec. exposure time each. The inverted version on the bottom clearly shows the two tails of the comet.

Comet C/2013 US10 (Catalina)

Comet C/2013 US 10 (Catalina) imaged in L with a GSO 254mm f/5 Newtonian telescope and an ATIK 383L+ mono CCD camera

Comet C/2013 US10 (Catalina)

Comet C/2013 US 10 (Catalina) imaged in L with a GSO 254mm f/5 Newtonian telescope and an ATIK 383L+ mono CCD camera

 

Aurora Borealis – observed from Vallentuna

It is an amazing spectacle when a solar storm of charged particles hits the Earth’s magnetosphere. The particles following the magnetic field finally collide with particles of the Earth’s atmosphere – mostly oxygen and nitrogen. These collisions lead to either an ionization or excitation of atoms/molecules at an altitude of around 100 km. Subsequently, the recombination is responsible for the emission of a photon. The typically green colour arises from oxygen. On March 17, 2015 a strong solar storm hit the Earth and even at the relatively low latitude of Stockholm one could follow this energetic event.

Aurora Borealis observed from Vallentuna (Stockholm, Sweden)

Aurora Borealis observed from Vallentuna (Stockholm, Sweden)

Aurora Borealis observed from Vallentuna (Stockholm, Sweden)

Aurora Borealis observed from Vallentuna (Stockholm, Sweden)

 

Comet C/2014 Q2 (Lovejoy)

Comet C/2014 Q2 (Lovejoy) is bright (around 5mag) enough to be easily seen with binoculars or small telescopes in constellation Eridanus. On really good sites one should be able to spot it even with naked eye. However, currently the observing conditions are hard, because of today’s full moon. Additionally in the northern hemisphere the comet’s elevation is very low. I have spotted it two days ago from Vallentuna (near Stockholm, Sweden) when it was only 18 degrees above the horizon at maximum. I have taken some pictures with my CCD camera and was really impressed how fast the comet moves on the sky (see video).

The really good news is that the observing conditions are going to be better during the next days and weeks. C/2014 Q2 (Lovejoy) will climb further up, reaching constellation Taurus around 9th of January, just two days after it reaches the closest position to Earth at a distance of around 70 million kilometers.

Ringsystem um Asteroid “Chariklo” im äußeren Sonnensystem entdeckt

Die Europäische Südsternwarte (ESO) berichtet in Ihrer heutigen Pressemitteilung von der überraschenden und erstmaligen Entdeckung eines Ringsystems um einen Asteroiden. Der Planetoid Chariklo wurde von mehreren Observatorien aus – darunter auch La Silla in Chile – beobachtet. Grund der Beobachtung war eine bevorstehende Sternbedeckung durch den Asteroiden. Solche Ereignisse werden genutzt, um die Größe von Kleinplaneten abzuleiten. Dabei wurde überraschenderweise kurze Zeit vor sowie kurze Zeit nach der eigentlichen Bedeckung, ein Helligkeitsabfall des Sterns registriert. Daraus kann zweifelsfrei geschlossen werden, dass sich um Chariklo ein Ringsystem aus Staub und Eis gebildet haben muss ähnlich wie man es von Saturn, Uranus oder Neptun kennt. Letztere wurden ebenfalls durch Sternbedeckungen entdeckt.

Die Scheibe aus Eis und Staub könnte dabei das Resultat aus einem Impaktereignis sein. Weiters ist nun anzunehmen, dass Chariklo noch kleinere Begleiter hat, welche das Ringsystem aufrechterhalten.

Ring um Planetoid entdeckt

Image Credit: ESO

Planeten mit der Webcam

Jupiter

Jupiter

  • Datum: 21.04.2006
  • Zeit: 00h 00m
  • Ort: Sophienalpe
  • Aufnahmetechnik: Webcam: Philips ToUCam Pro (640×480 Pixel); fokal mit 2xBarlow am VC200L
  • verwendeter Filter: IR Sperrfilter
  • Brennweite: 3600mm
  • Blende: f/18
  • Belichtungszeit: je 1/250
  • verwendeter Film: CCD Chip
  • digitale Bildverarbeitung: Addition von ca. 500 Einzelbildern mit Registax, dann 2fache Vergrösserung

Saturn

Saturn

  • Datum: 20.04.2006
  • Zeit: ca. 23h 45m
  • Ort: Sophienalpe
  • Aufnahmetechnik: Webcam: Philips ToUCam Pro (640×480 Pixel); fokal mit 2xBarlow am VC200L
  • verwendeter Filter: IR Sperrfilter
  • Brennweite: 3600mm
  • Blende: f/18
  • Belichtungszeit: je 1/250
  • verwendeter Film: CCD Chip
  • digitale Bildverarbeitung: Addition von ca. 500 Einzelbildern mit Registax, dann 2fache Vergrösserung