Public Outreach

Perhaps you remember a 18 months ago we had a post about a new comet discovered by Pan-STARRS that was due to visit the inner Solar System in early 2013. The comet is currently observable by amateur astronomers with small telescopes in the Southern Hemisphere. One the 9th of January, John Drummond in New Zealand imaged C/2011 L4 (PANSTARRS) and measured its integrated magnitude to be 8.1. This is slightly brighter than the Minor Planet Center predicted brightness. If it maintains this brightness excess relative to the prediction, the peak brightness will be magnitude -0.2, which should make it visible to the naked eye in a dark sky. The comet is predicted to reach its peak brightness on March 10, when it should be visible low in the western sky right after sunset.

Today’s Astronomy Picture of the Day is a spectacular Pan-STARRS picture of the Triffid and Lagoon nebulae. Here’s the lower resolution version.

The Triffid and Lagoon Nebulae. Credits: Eugine Magnier (UH IfA), Peter Draper & Nigel Metcalfe (Durham University), ©PS1 Consortium

APOD also has a higher (1/10) resolution version, but you can explore the image at 3 times the resolution using this interactive version. Have fun exploring, maybe while looking around you could spot this,

The globular cluster NGC 6544 Credits: Eugine Magnier (UH IfA), Peter Draper & Nigel Metcalfe (Durham University), ©PS1 Consortium

It’s the globular cluster NGC 6544, discovered in 1784 by William Herschel. This lies about 3kpc from the Sun. Globular clusters are found in the halo of our galaxy and are much older and denser that open clusters such as Messier 21 (more of which later).

To make the image, 12 dithered 40sec exposures were stacked in each of three different coloured filters, so the total exposure was only about 8mins per filter. The dithering is necessary as the Pan-STARRS gigapixel camera is made of many individual CCD detectors bonded to the same piece of silicon, and there are unavoidable gaps at the joins where no light is captured. By moving where the camera is pointing slightly between exposures we can ensure that every bit of sky is seen at some stage. As, for scientific purposes, the Pan-STARRS data normally has any background light removed, special software techniques were employed to ensure the nebulae did not dissappear!

The resulting three greyscale images were then aligned and combined using the GIMP photo processing package into an RGB colour picture, a technique quite familar to amateur astrophotographers. To make the colours, the g filter was mapped to the blue channel, the r filter to green and the i filter (which is near infra-red, and would be invisible to the eye) to red. This combination is necessary as Pan-STARRS does not have a Visual filter, which would normally mapped to green. It does have the unusual consequence that hydrogen alpha emission, which at a wavelength of 656nm would look red to the naked eye, comes out looking green on the picture!

The idea for taking images of these particular nebulae came from PS1 scientist Nigel Metcalfe after taking a picture of them with his 4 inch refractor while on holiday in Wales.

Messier 20 is the famous Triffid Nebula. This is actually a star forming nursery, with three objects for the price of one: a cluster of young stars, an emission nebula, seen here glowing green due to hot hydrogen gas, and a blue reflection neubula, where starlight (from the cluster) is reflected off dust grains.

M20, the Triffid Nebula. Credits: Eugine Magnier (UH IfA), Peter Draper & Nigel Metcalfe (Durham University), ©PS1 Consortium

Messier 8, otherwise known as the Lagoon nebula, is a giant interstellar cloud and stellary nursary. It contains several Bok globules which are dark clouds of dense material in the process of collapsing to form stars, see if you can find a few.

M8, the Lagoon Nebula. Credits: Eugine Magnier (UH IfA), Peter Draper & Nigel Metcalfe (Durham University), ©PS1 Consortium

The Planetary Nebula M1-40. Credits: Eugine Magnier (UH IfA), Peter Draper & Nigel Metcalfe (Durham University), ©PS1 Consortium

The open cluster Messier 21. Credits: Eugine Magnier (UH IfA), Peter Draper & Nigel Metcalfe (Durham University), ©PS1 Consortium

There’s also other things to look out for in the image. For example M1-40 (left), a planetary nebula lying 2.8kpc from the Sun. Despite the name, these are really stars which have shed their outer layers. It is this hot hydrogen gas which we see glowing brightly.

And then there’s also Messier 21 (right) a relatively young open cluster of stars, believed to be only 4.6 million years old, lying 1.3kpc from the Sun. An open cluster is a group of up to a few thousand stars inside our galaxy that were formed at roughly the same time from the same gas cloud.

It’s March 15th 2012, the official start date of the fourth Pan-STARRS Asteroid Search Campaign of the International Astronomical Search Collaboration. Students from 40 schools - most of them from the United States and Germany, but also from Brazil, Bulgaria, England, India, Poland, and Taiwan - are ready to go. During the last few weeks, they practiced how to search for asteroids in astronomical images. Now they will have the opportunity to work with data from the Pan-STARRS PS1 telescope - and to discover several previously unknown objects in our solar system for the next five weeks.

The International Astronomical Search Collaboration (IASC) is a cooperation of American universities, international observatories, and educational partners with the aim to give students worldwide access to astronomical research data. Since October 2010, the Pan-STARRS PS1 Science Consortium semi-annually provides sets of images from the PS1 telescope to IASC. These data are full of so far unknown asteroids yet to be discovered - a job that is assigned to the schools that - partnered in teams - participate in IASC’s asteroid search campaigns. For the students, this project is a unique experience. They have exclusive access to the newest data from a professional telescope, and they can use it to learn how to apply scientifc methods. Finally, they have the chance to be the first to spot a celestial body no one else has ever seen before.

At the Haus der Astronomie in Heidelberg, I coordinate a growing network of German teachers who participate in the IASC campaigns with their students. We set up a Yahoo group where teachers and students can discuss problems or their findings with the other German-speaking groups. I also created German versions of the IASC manuals, and the Haus der Astronomie provides supplementary German-language educational material that the teachers can use in class to complement the asteroid search campaigns.

March 19th. Images taken on March 16th by the PS1 telescope are finally processed for the schools. The students download them, and, using the software Astrometrica, they search for moving objects and measure their positions on the sky. They report their findings to IASC, where the data is cross-checked with the results of Pan-STARRS’ automated search. And they are quite successful: The eight German schools supported by the Haus der Astronomie alone spotted a total number of 44 new asteroids. But for some of the students, just having discovery candidates is not enough. They want to do their own follow-up observations, in order to recover as many of their findings as possible.

Asteroid 2011 WC1 re-observed with Faulkes Telescopes after it was discovered by LGL student Julia Schnepf during the fall 2011 IASC Pan-STARRS asteroid search campaign.

The discovery of an asteroid is a three-step process: An initial candidate must be confirmed by further observations in order to get designated by the Minor Planet Center (MPC). The asteroid will finally be numbered when it can be monitored for several oppositions, a procedure that typically takes several years. And not till then, the discoverers are officially credited and are allowed to name it. Especially for the second step, follow-up observations are essential. This work is usually done by IASC astronomers, but my aim is to widen the project and to involve the students themselves in this process.

One of the German schools participating in the Pan-STARRS asteroid search campaigns is the Lessing-Gymnasium Lampertheim (LGL), which has a focus on natural sciences and is a member of the German STEM network MINT-EC. Since 2010, the LGL participates in a pilot project with the Faulkes Telescope Project (FT)in Germany, which started in 2004 with the focus on the coordination of asteroid observations. 650 positions of 115 asteroids have been measured and reported to the MPC until 2005; three asteroids have been discovered and designated, two of them have been numbered and named by students. Additional activities include photometry of the eclipsing binary asteroid (4492) Debussy. In the framework of this project, the LGL has access to the 2-meter telescopes of FT, which are perfectly suited for follow-up observations of the Pan-STARRS asteroids, which are typically fainter than magnitude 20. During the October 2011 IASC Pan-STARRS campaign, I therefore initiated a project together with teacher Martin Metzendorf and Lothar Kurtze from the German FT team, where students aged 12 to 17 plan and perform follow-up observations of the asteroids discovered during the Pan-STARRS campaign within regular physics classes or at the astronomy club of the LGL.

Doing their own observations provides the ultimate hands-on experience for the students. Telescope time at FT is booked in advance, but for reasonable follow-up observations, their candidates must be caught within the next few days after their initial discovery. So first of all, the students learn how important it is to be as fast as possible with the analysis of their Pan-STARRS data. They can use the position measurements of their own Pan-STARRS discoveries or data from the other groups to calculate a preliminary ephemeris of these asteroids with MPC tools. This way, coordinates where the telescope should be pointed at for recovery can be predicted. Additionally, observing with FT means that the students themselves are responsible for controlling the telescope and its camera. Subsequently, they analyse the obtained images like they did for the Pan-STARRS data. Finally, the positions they measure for the recovered asteroids are checked by the FT team and sent to the MPC.

Something else happens on March 19th. The PS1 telescope itself points at the same region of the sky it did three nights ago, thus matching the images the students got. As a result, the schools supported by the Haus der Astronomie can celebrate the confirmation of 12 of their candidates already during the first week of the Pan-STARRS campaign - what an outstanding start.

Nevertheless, the LGL students are well-prepared. On April 3rd they started their follow-up observations with FT during this campaign, and already during their first run, they were able to recover two candidates. Additionally, they plan to monitor the designated asteroids discovered by German schools during previous campaigns in order to get them numbered.

One of the many exciting aspects of being involved in the Pan-STARRS PS1 survey is the potential to utilize its data products for education and public outreach purposes (EPO). Members of the PS1SC have recently completed some extremely successful work with the International Astronomical Search Collaboration to allow high school students in Germany, Texas, and Hawaii an opportunity to use images collected by PS1 to make asteroid discoveries. This first “pilot project” of 10 schools will be expanded to about 30 schools in a second “campaign” to be conducted during Spring 2011, and eventually the expansion could reach several hundred or even a thousand schools (thousands of students). And because of the vast amount of data produced by the wide field PS1 images, it requires only a handful of images to support such a large number of schools. For me the most gratifying part of bringing asteroid searches into the classroom is the high enthusiasm expressed by both the students and their teachers for participating in this program.

For the past few months we have teamed up the Pan-STARRS 1 telescope, designed to become one of the world’s most powerful asteroid hunters, with school students from the USA and Germany to discover and study asteroids – clumps of rock, between a couple and a few hundred kilometers in size, that cruise through our Solar System. At the close of the campaign, which was coordinated by the International Astronomical Search Collaboration, the students can look back on exciting eight weeks of asteroid search, which included the confirmation of four “Near-Earth Objects” (asteroids passing relatively close to Earth) and the discovery of what could turn out to be more than 170 previously undiscovered asteroids.

Asteroid 2010 UR7, confirmed as a Near Earth Object by students at Gymnasium Neckargemünd near Heidelberg. The object is indicated by the white box and appears as a faint streak as it moves through the solar system so fast it is blurred out in even a 40s image! Credit: PS1SC

As the 1.8 meter (71-inch) Pan-STARRS 1 telescope (PS1), one of the most powerful current survey telescopes, scans the night sky, its 1400 Megapixel digital camera takes more than 500 exposures per night. Between October 25 and December 21, 2010, a small fraction of these data found its way into classrooms in the USA and in Germany, where high-school students have used it to track known asteroids, and also to discover candidate objects that could be previously unknown asteroids. When Hawaiian skies were overcast, schools also received data taken with a telescope operated by the Astronomical Research Institute (ARI) in Westfield, Illinois.

Over the Internet, the participating schools received series of astronomical images. Each series included images of one specific region of the sky, taken an hour apart. During this hour, the image of a main belt asteroid (one lying between Mars and Jupiter) would have moved noticeably (in the images in question: about 100 pixels) relative to the distant background stars. The students examined the images for exactly this kind of position change, carefully sorting image artifacts from moving celestial objects, and reported back to the International Astronomical Search Collaboration, whose volunteers then checked the results and arranged for follow-up observations.

Some of the most interesting student observations during the project concerned “Near-Earth Objects” (NEO), asteroids or similar objects whose orbits bring them into the inner Solar System. Some NEOs might turn out to be potential “killer asteroids” that are bound to collide with our home planet; finding these is one main goal of the PS1 telescope. In order to keep track of NEOs, at least two separate observations at different times are required. Katharina Stöckler (age 17), an 11th grade student at Gymnasium Neckargemünd near Heidelberg, explains:

“We obtained a ‘NEO confirmation’ for the asteroid 2010 UR7 – the second observation ever made of that object, which confirmed the asteroid’s existence and gave crucial information about its orbit.”

Three additional such “NEO confirmations” were made during the project; in addition, 64 of the students’ observations amounted to the third or fourth time a specific NEO had been observed. All these observations provide important additional data to scientists studying the motion of NEOs.

In the course of the project, the students also observed 151 candidate objects in the Pan-STARRS data (plus an additional 20 candidates in the ARI/Westfield telescope data) that could be newly discovered main belt asteroids, which orbit the Sun between the orbits of Mars and Jupiter. In one case, students from Benedikt Stattler Gymnasium, a high-school in Bavaria, Germany, discovered 7 such candidate objects in a single night! Before the students’ finds are confirmed as discoveries, however, and assigned provisional designation numbers, they will need to be observed again – for a number of the candidates, this is going to prove impossible; on the other hand, some are likely to turn out to have been previously known, after all. Once a newly found object has been observed over at least a whole orbit (which typically lasts 3 to 6 years), it is assigned a definite numerical identifier, and can also be given a proper name.

IASC director Dr. Patrick Miller, of Hardin-Simmons University in Abilene, Texas, says:

“Pan-STARRS images contain an amazing amount of data, providing students with opportunities for literally hundreds of new discoveries. With this amount of data, we could expand our campaign to a thousand schools a year, and tens of thousands of students, which is very exciting, and is an unbelievable opportunity for high schools and colleges!”

It is incredibly exciting that we can use a state-of-the-art system such as Pan-STARRS to allow students around the world to learn astronomy with real research quality images. We hope we’ve made this a valuable and enjoyable experience for both the students and their teachers. Hopefully this is only the first step in eventually involving as many as a thousand schools around the world.

If you’re interested in your school getting involved please email me at burgett AT ifa.hawaii.edu

More information can be found in this press release:

“Successful hunt for asteroids in the classroom”
Dr. Markus Pössel, Center for Astronomy Education and Outreach
Max-Planck-Institute for Astronomy

The participating international teams of schools were:

1. Luitpold-Gymnasium, Munich, Germany
Ranger High School, Ranger, Texas

2. Christoph-Probst-Gymnasium, Munich, Germany
May High School, May, Texas

3. Benediktinergymnasium Ettal, Germany
Vernon High School, Vernon, Texas

4. Benedikt-Stattler-Gymnasium, Bad Kötzting, Germany
Bullard High School, Bullard, Texas

5. Werdenfels-Gymnasium, Garmisch-Partenkirchen, Germany
Colleyville Heritage High School, Colleyville, Texas

6. St. Anna-Gymnasium, Munich, Germany
El Campo High School, El Campo, Texas

7. Helmholtz-Gymnasium, Heidelberg, Germany
Tarrant County College, Hurst, Texas

8. Gymnasium Neckargemünd, Neckargemünd, Germany
Brookhaven College, Farmers Branch, Texas

9. Lessing-Gymnasium, Lampertheim, Germany
Madisonville High School, Madisonville, Texas, and Baldwin High School, Wailuku, Hawaii

10. Life Science Lab, Heidelberg, Germany
Collin County College, Plano, Texas