Entries tagged as astronomy

Asteroid Vesta & dwarf planet Ceres

3 days of observing Vesta and Ceres (42% size)

I've recently bought a motorized equatorial mount called iOptron SkyTracker, which enables the camera to track the stars at the same speed as they move in the sky. This is useful for photographing faint objects through long exposures. But since the light pollution in the city sky hinders long exposure photography in the first place, I was unsure whether this would be of much use.

To see that the mount works as intended and is still useful under an uncooperative sky, I decided to try photographing two kinds things - asteroids and galaxies. For asteroids, the two brightest, Vesta and Ceres, were chosen. They were close to each other while moving in the constellation Virgo, between Arcturus and Mars, in the southern sky around midnight. Ceres is also a dwarf planet, so I would be photographing two types of celestial body at once.

For three nights (April 21-22, 23-24, and 24-25), I photographed the area just above Zeta Virginis (a.k.a. Heze) to catch the movement of two objects. The SkyTracker mount was used on the first and third night because the sky was clear, but the second night was riddled with fog in the lower sky, hindering the view of Polaris which is needed to calibrate the mount. So I had to take the photo using only the camera on high-ISO, (relatively) short exposure settings.

Two things became evident in this round of photographing. One, Vesta (magnitude 5.7) and Ceres (magnitude 7.0) could be clearly seen moving towards west each day. Two, the SkyTracker mount did an excellent job tracking the stars and the asteroids, producing images far better than using camera only. The second night's photo had small streaks, despite having only 10 seconds of exposure. Here are the full resolution photos used for the animation.

  
Full resolution crops of Vesta and Ceres

Device: Canon SX50 HS
Filters: None
Location: Suwon, Korea

#1: 121mm - ISO 80 - 300s - f/5.0 - 2014-04-22 00:05 KST
#2: 121mm - ISO 1600 - 10s - f/5.0 - 2014-04-24 00:07 KST
#3: 119mm - ISO 80 - 300s - f/5.0 - 2014-04-24 23:19 KST

Today's "The Toon-Box"

Mars closest approach of 2014

Mars and the Moon

Mars comes very close to Earth every 780 days or so. This happened again last night - distance between Mars and Earth was 0.618 AU. The last time Mars made an approach closer than this was back in December 19, 2007, when it was 0.589 AU. At these distances, Mars is 15 arc seconds big, which registers as 10 pixels wide on my SX50 HS at maximum optical zoom. Until the next approaches on May 31, 2016, or July 31, 2018, this is about as big as it gets for the camera. Still, using both the 2x digital teleconverter and RegiStax stacking, I was able to get a clearer image of the planet from the multiple photos.

Meanwhile, a full moon was right next to Mars yesterday. This created a good opportunity to take both the Moon and Mars in the same photo. Full moon is quite bright, but Mars was also shining at its peak (-1.4 magnitude), so it was holding on its own. Interestingly, a lunar eclipse is also supposed to happen today, dimming the Moon so that Mars would be easier to see. But it happens during the day here, while both the Moon and Mars are below the horizon. So that's no go for me.

The lunar eclipse that is visible in my country would happen on the early evening of October 8, 2014, starting as the Moon rises from the horizon. At that time, the faint Uranus (5.7 magnitude) would be next to the Moon. I wonder if the eclipsed Moon would be dim enough for me to see the planet, weather and location permitting.

Device: Canon SX50 HS
Filters: None
Location: Suwon, Korea

Main Image
Settings: 351mm (reduced to 20%) - ISO 80 - 1/80s - f/5.6
Time: 2014-04-14 23:34 KST

Inset
Settings: 1200mm (w/ 2x Digital TC) - ISO 80 - 1/200s - f/6.5
Time: 2014-04-14 23:23 KST
41 photos stacked with RegiStax 6.1.0.8
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A sideways ISS pass

ISS pass for April 6, 2014

ISS turns
This series of images I took of the International Space Station (ISS) seem to explain the "sideways" view of the station I've taken a few times before better. Until the close approach, only the center area is visibly illuminated. At the closest point, the solar panels stretching from top to bottom become apparent.

The panels form the two columns of the "H" shape when viewed from the "front". But in these images, the shape is more like a mirrored "ㅔ". I guess this view can reveal a docking spaceship, if there is one and is big enough.

Device: Canon SX50 HS
Settings: 1200mm (2x enlarged) - ISO 160 - 1/320s - f/6.5
Filters: None
Time: 2014-04-06 20:35 KST
Location: Suwon, Korea
Max Magnitude: -3.6
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Ursa Major & Leo Minor

Ursa Major (yellow, left) and Leo Minor (blue, right)

Shortly after watching the MetOp-A satellite flare, I pointed the camera vertically up for a test of how long I could leave the shutter open before the light pollution whitened things out. In the process, the entirety of two constellations, Urga Major and Leo Minor, were caught in the resulting photo. The Big Dipper makes up the bottom portion of the Ursa Major.

If you click on the image for the full resolution version, the star trails are noticeable. I'll be trying out a star tracker I recently bought to see if this can be effectively eliminated. Too bad the weather these days are generally cloudy.

Device: Canon SX50 HS
Settings: 24mm - ISO 80 - 60s - f/3.4
Filters: None
Time: 2014-04-08 21:31 KST
Location: Suwon, Korea
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