Category Archives: astronomy

“Aurora” over Providence

Note: this was originally published on March 6. It was updated on March 8 to include new information.

On March 6 we received local reports that the aurora was observed in New England just before sunrise. One of our visitors described seeing it from a rest area on Route 495 near Boston. There was another report from Vermont. Our automated all sky camera was running the entire night and captured the view above Providence. Also visible is the International Space Station (ISS) streaking through the sky about 500 miles from Providence as the planets Mars and Saturn shine brilliantly in the south.

ISS and aurora
A 10 second exposure taken March 6, 2016 at 4:54:18 AM EST. This image has been processed to make it easier to see the stars.

During the night the camera recorded 3,750 images of the sky. North is at right, west at bottom, and the zenith is at center. The field of view is about 140 by 90 degrees, capturing most of the sky above Providence. The images can be processed to produce a time lapse movie that shows 5 minutes of changes in the sky per second of video. Click on the image below to watch an excerpt. A number of artificial satellite can be seen streaking through the sky just before dawn.

Our sky camera has been in operation since the spring of 2008. We’ve never captured images like this before. Continue reading “Aurora” over Providence

Asteroid misses Earth, film at 11

A Near-Earth Object is an asteroid or comet that is in an orbit that sometimes brings it close to the Earth.  The largest of these are known as Potentially Hazardous Objects as they could cause significant damage if they impacted our planet. There are sometimes news reports of a “close approach” where an object passes particularly near the Earth. An  asteroid called 2013 TX68 will pass the Earth on March 8, 2016. It is estimated to be 100 feet in diameter.

orbit of asteroid 2013 TX68
The orbit of asteroid 2013 TX68 in relation to the Earth.

Continue reading Asteroid misses Earth, film at 11

“An Astronomical Blunder”

“An Astronomical Blunder. — Professor Waltemath of Hamburg recently announced through a private circular that he had discovered a second moon to our earth. The contents of the circular were the basis of sensational articles in leading newspapers… He also quotes descriptions of strange objects in the sky seen at various times since the sixteenth century, which his calculations show were probably this second moon.”

The Cyclopedic Review of Current History, 1898

Georg Waltemath
“Dr. George [sic] Waltemath. The German astronomer, who says he has discovered a second moon circling around the earth.” – Chicago Daily Tribune, March 22, 1898.
Georg Waltemath made an extraordinary claim: that the Earth had a second moon. It was supposed that it was much smaller and dimmer than the known moon. He calculated that this object orbited the Earth every 119 days and would pass between the Earth and Sun, on average, every 177 days. He predicted that on February 3rd of 1898 it would be visible in silhouette as it moved across the disk of the Sun, an event known as an astronomical transit.

Winslow Upton was skeptical of the existence of this long unnoticed moon, but nonetheless attempted to observe it. Continue reading “An Astronomical Blunder”

“A catastrophe of stupendous import”

“Prof. Winslow Upton, of Brown university, one of the most learned astronomers in the country, has been busily engaged at the Ladd observatory, making photographic exposures of the constellation Perseus, in which the new star appears, and has given out an interesting statement concerning the unusual event. He says:”

– “Catastrophe of tremendous import believed to have caused appearance of bright new star.” The Detroit Free Press, Feb. 27, 1901.

Winslow Upton
Winslow Upton (1853-1914), professor of astronomy and director of Ladd Observatory

“The appearance of this brilliant star is a rare astronomical event, not equaled in the memory of anyone now living. In fact, no similar event has occurred since the time of Kepler in 1604.”

“The term ‘new star’ or ‘Nova’ is applied to stars which unexpectedly increase their brightness and then fade out again. It is not supposed that any of them are new creations, since those whose histories are best known have been observed as faint stars before the outburst which made them famous. Probably every year witnesses occurrences of this kind, but unless the increase of light is very pronounced it may not be detected among the great multitude of stars.” Continue reading “A catastrophe of stupendous import”

“The pendulum of eternity”

“The vast cycles of change going on in the heavens seem, as it has been sublimely said, like the recurring beats of the pendulum of eternity.”

– William Augustus Norton, First Book of Natural Philosophy and Astronomy, 1860.

Providence Union Station, 1847-1896.
Providence Union Station, 1847-1896. The Foucault pendulum was suspended within one of the towers at left.

When news of Léon Foucault’s demonstration of the Earth’s rotation reached the United States in 1851 there was great interest in repeating the experiment in Providence. Two members of the Brown faculty arranged for a public demonstration in the Providence railroad depot. Alexis Caswell was a professor of natural philosophy, mathematics, and astronomy. William A. Norton was professor of civil engineering and natural philosophy. The pendulum bob weighed a little less than 40 pounds and was suspended from the end of a wire 97 feet long. The report on this experiment was published in the Proceedings of the AAAS along with an account of the Harvard demonstration in the stairwell of Bunker-Hill Monument. Continue reading “The pendulum of eternity”

Timing the transit of Mercury, 1907

“About five seconds before third contact a black ligament connected the planet’s disk with the trembling edge of the Sun.”

– Winslow Upton, “Transit of Mercury at Ladd Observatory.” Popular Astronomy, 1907.

1907 transit of Mercury
Chronograph recording of the Transit of Mercury on November 14, 1907.

Prof. Winslow Upton tapped a telegraph key as he watched the planet Mercury transit the Sun. The signal was sent to a chart recorder where an electromagnet moved a pen on a slowing turning drum of paper to record the observation. The instrument is called a chronograph. This one was made by the Warner and Swasey Company of Cleveland in 1890. Primarily it was used for calibrating the astronomical regulators (precision pendulum clocks) to set the time accurately. It was also used for timing events such as lunar occultations of stars. Continue reading Timing the transit of Mercury, 1907

The dark side of the Moon

Automated instruments on the roof of Ladd Observatory monitored the sky during the total lunar eclipse of Sept. 27-28, 2015. First there is a wide field sky camera. It has a fish-eye lens which can capture an image of most of the sky above Providence. The second is a sky brightness meter which is used to monitor light pollution.

Eclipse sky
An image from the sky camera during the total phase of the eclipse. (Click on the image to see a time lapse video.)

The full Moon is usually so bright that it overwhelms the sensitive camera causing the images to be overexposed. During the eclipse the Moon was dark enough that the only artifact in the image above is a thin vertical line where one column of the digital camera was saturated by the moonlight. The camera is more sensitive than the human eye allowing the Milky Way to be seen during the total phase of the eclipse. The time lapse video contains 3,625 still images. Each second of the movie shows about 5 minutes of changes in the sky. Continue reading The dark side of the Moon

2012 Geminid Meteor Shower

The Geminid meteor shower peaked on Dec. 13 – 14, 2012. At Ladd Observatory we operate an automated camera on the roof which takes an image of most of the sky every 10 seconds. There were many small meteors and a number of medium meteors that we captured during the night. Here are the four best images. Each is a 10 second exposure with a field of view of about 140 by 90 degrees. North is at right and west is at bottom.

Watching the skies for meteors

There are some times during the year when a number of meteors can be seen in the sky. For example, the recent Quadrantid meteor shower during the early morning hours of January 4th. But late January is not usually a time that you would expect to see meteors. It is possible, though.

At the Ladd Observatory we’ve been testing a sky camera to watch for interesting phenomena in the night sky. The camera has a field of view of 90 by 140 degrees which can take an image of nearly the entire sky every 10 seconds.

sky camera
The small gray weather proof box in front of the dome on the roof of Ladd Observatory contains a digital all sky astronomy camera which is used to capture images of the night sky.

Continue reading Watching the skies for meteors

2012 Quadrantids

There is a digital camera in a weather proof box mounted on the roof of Ladd Observatory. The camera has a wide field (“fish eye”) lens that can take an image of nearly the entire sky. North is to the right, and east is at top.

Tonight is the Quadrantid meteor shower. The camera has been running for most of the night taking 10 second exposures.

The first image shows a spectacular meteor in the same part of the sky as the planet Mars which is the bright dot behind the meteor.
Quadrantid meteor

A very bright meteor from the Quadrantids at 3:00:08 am EST.

We recorded 12 bright meteors between 1am and dawn. There are probably also a number of very dim meteors in the images from this morning but I haven’t had a chance to count those. The meteors were mostly seen between 1:38 and 3:10 am EST which is when the shower peaked. However, one of the two brightest meteors was seen much later.

Quadrantid meteor
A bright Quadrantid meteor in the northwest at 04:44:02 AM EST.