Andrew C. Layden


Chair, Department of Physics & Astronomy
Bowling Green State University
Bowling Green, OH 43403

Office: 104C Overman
voice: 419-372-8653
FAX: 419-372-9938


  • B.A. - Wesleyan University
  • Ph.D. - Yale University  


  • Astrophysics
    • Photometry of variable stars in old stellar populations: RR Lyrae, Long-period variables, Cepheids
    • Spectroscopy of RR Lyrae variables: chemical abundances and kinematics
    • Determination of basic properties of RR Lyrae variables: absolute magnitudes and intrinsic colors

Selected Publications:

Caddy, R.V., Layden, A.C., et al. 2022, PASP, 134, 094201, "Optical Time-Series Photometry of the Symbiotic Nova V1835 Aquilae"

Zinn, R., Chen, X., Layden, A.C., & Casseti-Dinescu, D.I. 2020, MNRAS, 492, 2161, "Local RR Lyrae stars: native and alien"

Layden, A., Tiede, G.P., Chaboyer, B., Bunner, C., & Smitka, M., 2019, Astronomical Journal, 158, 105, "Infrared KS-band Photometry of Field RR Lyrae Variable Stars"

Osborn, W., Kopacki, G., Smith, H., Layden, A., Pritzl, B., Keuhn, C., & Anderson, M., 2019, Acta Astronomica, 69, 101, "Variable Stars in M13. III. The Cepheid Variables and their Relation to Evolutionary Changes in Metal-poor BL Her Stars"

Osborn, W., Layden, A., Kopacki, G., Smith, H., Anderson, M., Kelley, A., McBride, K., & Pritzl, B., 2017, Acta Astronomica, 67, 131-158, "Variable Stars in M13. II. The Red Variables and the Globular Cluster Period-Luminosity Relation"

Abbas, M., Layden, A., Guldenschuh, K., Reichart, D. Ivarsen, K. Haislip, J., Nysewander, M., LaCluyze, A. & Welch, D. 2015, AJ, 149, 40-49, "Variable Stars in Metal-Rich Globular Clusters. IV. Long Period Variables in NGC 6496"

Click here to access supplemental data from papers/projects, and here for FORTRAN software used therein.

Click here to access my aging but still functional [like me?] webpages.


Over the years, we have had a number of students who excelled in amateur astrophotography. Here, I have assembled some nice examples of their work.

Shaun Sager '21 did several projects with me, including wide-field imaging of constellations and trains (PDF, 2.7 Mb) using his 35 mm DSLR, as well as some images of Messier deep-sky objects (PDF, 13.6 Mb) using BGSU's 0.5-m telescope and CCD camera.

Scott Call MS’21 is a long-time and accomplished astrophotographer – you can see his work on Instagram @astroscottography  

July 2021 – I purchased a solar-system video camera for the BGSU Observatory and took some “slide past” videos of the moon which I posted on YouTube.

Justin Chapman MS’22 shares his astrophotos on Instagram @astrophotochap

Bo Royer MS’22 also has taken many nice deep-sky images (details and links coming soon).

Fall 2022 – my ASTR 3090 course “Observational Astronomy” explored astrophotography using cell phones and the SS-video camera (using seeing-selected, stacked and sharpened frames to create high-res stills) on our 8-inch telescopes, producing an exhibit at BGSU’s ArtsX “Experiment” show.

Jacob Beavon MS’23 uses his DSLR camera to take sequences of images which he stacks to create beautiful digital star trail images. The image below was taken on July 31, 2022 at the Doyt Perry stadium at BGSU.



Two videos to help you build a simple, 3D model explaining the phases of the moon (4:23), and how they relate to solar and lunar eclipses (7:37). Useful for kids, teachers, and adults. Links to YouTube.

Updated: 02/15/2024 02:45PM