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Transitsearch Ups the Ante

Buy a commercial telescope today, equip it with a CCD detector, and you’re arming yourself to enter the exoplanet hunt. A CCD, or charge-coupled device, is a sensor that proves far more efficient than photographic film at capturing incoming light. It wasn’t so long ago that such tools were available only at large observatories, but no more. Today’s amateur can observe a planetary transit, sensing the slight dimming that the planet causes to the starlight as seen from Earth.

The trick is knowing when and where to look, and on that score, the Transitsearch network, often working with the American Association of Variable Star Observers, offers ephemeris and transit search results for stars thought to be candidates for such detections. For those new to the term, an ephermeris (pl. ephemerides) is a table plotting the position of celestial bodies. Look to Transitsearch for an example.

Greg Laughlin (UC Santa Cruz) noted this morning on the systemic site that he was overhauling the look and capabilities of Transitsearch. The new design isn’t fully functional yet, but the data are already flowing. Says Laughlin:

“The ephemerides are incrementally updated every ten minutes, and so the transit window column now has a much finer resolution. It gives a quick overview of which planets are transiting (or potentially transiting) right now.”

And is something more in the works? Laughlin notes that large radial velocity studies are usually accompanied by photometric observations made by the same team, thus keeping transit detections more or less in-house. “Ideally, we need to get an open-source dedicated radial velocity observatory up and running to really feed Transitsearch and the systemic backend, and we are looking at avenues to make this happen.” That’s an exciting concept indeed, and one we’ll follow with great interest as the number of detected exoplanets closes on 300.

Comments on this entry are closed.

  • Darnell Clayton June 12, 2007, 20:21

    I didn’t know that the average citizen could afford to buy tools to detect exo-planets!

    I think that this is a good thing, and combined with the American Association of Variable Star Observers will help further people’s interest in finding planets orbiting other stars (as it would be a great way for one to cement themselves in history).

    Who knows? Perhaps a discovery today may lead to you being famous a century from now because the planet you discovered just happened to have a moon orbiting it that was habitable or contained a civilization upon it.

  • Administrator June 12, 2007, 21:42

    Yes, it still amazes me that networks of amateurs are working with professionals to check on planetary transits around other stars. The advances in readily available technology within the next decade or so should be amazing to watch.

  • ljk June 23, 2007, 8:44

    Two Classes of Hot Jupiters

    Authors: Brad M. S. Hansen, Travis Barman

    (Submitted on 20 Jun 2007)

    Abstract: We identify two classes of transiting planet, based on their equilibrium temperatures and Safronov numbers. We examine various possible explanations for the dichotomy. It may reflect the influence of planet or planetesimal scattering in determining when planetary migration stops. Another possibility is that some planets lose more mass to evaporation than others. If this evaporation process preferentially removes Helium from the planet, the consequent reduction in the mean molecular weight may explain why some planets have anomalously large radii.

    Comments: 35 pages, 16 figures in Preprint format. Submitted to ApJ

    Subjects: Astrophysics (astro-ph)

    Cite as: arXiv:0706.3052v1 [astro-ph]

    Submission history

    From: Brad Hansen [view email]

    [v1] Wed, 20 Jun 2007 20:03:35 GMT (66kb)


  • ljk July 18, 2007, 8:33

    On Using the Rossiter Effect to Detect Terrestrial Planets

    Authors: W. F. Welsh, J. A. Orosz

    (Submitted on 17 Jul 2007)

    Abstract: We explore the possibility that the transit signature of an Earth-size planet can be detected in spectroscopic velocity shifts via the Rossiter effect. Under optimistic but not unrealistic conditions, it should be possible to detect a large terrestrial-size planet. While not suitable for discovering planets, this method can be used to confirm suspected planets.

    Comments: 7 pages, 6 figures; Figure 2 in the conference proceeding did not reproduce well, so three panels from that 9-panel figure are shown here

    Subjects: Astrophysics (astro-ph)

    Journal reference: Transiting Extrasolar Planets Workshop, ASP Conf. Ser. Vol 366, 2007; Eds. A. Afonso, D. Weldrake and Th. Henning, p. 176

    Cite as: arXiv:0707.2407v1 [astro-ph]

    Submission history

    From: William Welsh [view email]

    [v1] Tue, 17 Jul 2007 00:46:13 GMT (530kb)