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Applications for 2024 will be accepted online beginning September 1, 2023.


The mission of the Clay Postdoctoral Fellowship program is to support innovative astrophysics research by offering to the next generation of developing independent researchers full access to the unique facilities, research staff and resources of the Center for Astrophysics | Harvard & Smithsonian (CfA). Past Clay Fellows have gone on to faculty and research positions at major universities and research centers. Several have received astrophysics' most coveted awards: Packard Fellowships, the Heinemann Award, a NAS-Kavli Fellowship, and membership in the National Academy of Sciences. It is anticipated that successful applicants will follow in their footsteps.

Successful candidates will be outstanding researchers with demonstrated promise to contribute significantly to the future of the field. The CfA will award at least one Clay Fellowship and may award additional Fellowships depending on the strengths of the applicant pool. 



Requirements: The Clay Postdoctoral Program Awards is designed for candidates whose interests and proposed research programs fall under an active field of research at the CfA. Candidates are strongly encouraged to study the Index of Research Scientists in consideration of this requirement. Applicants are expected to pursue research programs of their own conception and design, and they should state clearly why they believe that their professional goals would be furthered through research opportunities at the CfA. Applicants are expected to demonstrate their capability for original research through several first-author refereed publications in major astronomy journals.

Academic Background: The Fellowship Committee welcomes applications from recent Ph.d. recipients. A short postdoctoral period especially at the Ph.d. institution is not a disqualification.

Clay Fellows have complete research independence in an environment that thrives on the ideas and contributions of early-career scientists. The Clay Fellowship offers the following benefits and opportunities:

  • Five-year appointment (renewal dependent on research progress)
  • Stipend of $76,000 in 2023 with an annual cost-of-living increase
  • Research budget of $16,000 for each year
  • Funding for health and dental benefits for the Fellow (and dependents if applicable)
  • One-time relocation allowance
  • Eligibility to propose as a Principal Investigator for external support
  • Opportunity to receive advice and mentoring from CfA researchers
  • Opportunity to gain direct experience in advising graduate, undergraduate students who are recruited for CfA internship and fellowship offerings tailored to their academic level
  • Delivering the Clay Fellowship Prize Colloquium (typically scheduled in the Fellow's second year)

Length of the Award: The Clay Postdoctoral Fellowship is awarded for a period of five years.

Start Date: July 1st, August 1st, or September 1st.

Annual Clay Colloquium: The Clay Fellow presents a research talk before the entire CfA community in early spring of their first year followed by a private reception.

The Center for Astrophysics | Harvard & Smithsonian Fellowships do not discriminate based on race, color, religion, sex (including gender identity, gender stereotyping, pregnancy, and sexual orientation), national origin, age, disability, genetic information, parental status, or marital status of any applicant. 


Applications are accepted online from September 1, 2022 to October 28, 2022, 17:00 GMT, through our website.

Online admissions materials and references are due before the deadline.

Please review the FAQ before beginning the online application.

The first time you go to the link below you will need to register for a login password. When you see the Login page, click on the "Update Account" button. This will take you to a form where you will create your account. Make sure that you remember your password so that you can return to the same application to finish your application, or to make changes.

The online application can be found at:


Application Instructions & Required Materials

Complete the following sections of the online application:

  • Personal Information Section of Online Application

  • Proposed Research Section of Online Application

Upload these files in PDF or Text Format:

  • ADS Bibliography URL

  • Curriculum Vitae

  • Research Proposal (up to 3 to 4 pages)

    • Proposals including figures and references should not exceed 4 pages. Shorter proposals are welcome and encouraged. The font type should be equivalent to Times New Roman, size 12.

  • Three Letters of Reference
    • Steps for submitting reference letters:

      1. Contact your references. Make sure that they are available to submit the reference and are willing to write a letter on your behalf.

      2. The applicant supplies the name and email of each referee in the application form.

      3. A message is emailed to each reference, which provides a unique URL.

      4. The reference uses the URL given in their email to upload the letter.

      5. Once the reference letter has been uploaded, the applicant will see "Complete" when checking the appropriate area of the application status page.

NOTE: The Smithsonian Astrophysical Observatory issues only J-1 visas to international exchange scholars selected for the Clay Fellowship Program. 


How do I apply? 

Applications will be accepted online from September 1, 2023 through our website.

Can I print the application form and mail it? 

If you are unable to use the online application, contact for more information.

How do I register online? 

Go to the Fellowship Application Login page. Select "Update Account" then "Register". On the Registration page, enter your full email address and a password of your choice. Repeat the password for verification and select "Register Now."

How do I create my own bibliography, a new requirement on the application page? 

You should create an ADS Library which contains all your papers by following the the steps outlined in this help page. After you create the library, make it public and share the public link in your fellowship application.

When is the deadline? 

The deadline is October 28, 2022, 17:00 GMT, for the Clay Postdoctoral Fellowship. It is the applicant's responsibility to ensure that all materials, including letters of recommendation, are received by the deadline. Incomplete applications -- and/or applications received after October 28, 2022 -- will not be considered.

Are there any requirements I must meet in order to apply?

Applicants are expected to pursue research programs of their own conception and design, and they should state clearly why they believe that their professional goals would be furthered through research opportunities at the CfA. Applicants are expected to demonstrate their capability for original research through first-author refereed publications in major astronomy journals.

What type of visa will the Smithsonian Astrophysical Observatory issue me if I am selected for the Clay Postdoctoral Fellowship? 

The Clay Fellowship is considered a non-service fellowship. It is not an employment position. Therefore, only J-1 visas are issued to international exchange scholars.

How should letters of recommendation be submitted? 

Letters of reference should be submitted by three "referees" familiar with your scientific abilities and must be received by the application deadline . The name and email of each referee must be supplied in the application form. A message is emailed to each referee, which provides a unique URL. The referee uses that URL to upload the letter. Once the letter has been uploaded, the applicant will see "Complete" when checking the appropriate area of the application status page.

What format is required for uploading files? 

Files should be in pdf format. If this is not possible, postscript or plain text is acceptable.

How do I submit my application? 

Your application is considered complete when you use the "Submit" button. You can update information until the application deadline even after marking your application as complete.

Can I edit my application online? 

Yes, you can access the application as many times as you want until the deadline. After entering the new information, click on the "Save" button. You can enter more information or edit existing information each time. You can upload new files to replace existing ones until the deadline.

If my password does not work, what should I do? 

On the "Fellowship Application: Login" page select "Reset Password" and a new password will be emailed to you if you have already successfully registered.

How will I know if all my application materials have been received? 

After logging in to the application, select "View Application Status" to check what remains incomplete in your application. In addition, when viewing your application online, you can check previously uploaded files by clicking on the numbered button provided.

What should I do if I notice an error in my application after I submit it? 

Until the deadline, you can access the application to make corrections, including uploading new versions of the pdf files.

What if I decide to withdraw my application? 

If you want to withdraw your application, send an email to stating your full name and the fellowship application you wish to withdraw.

What if I have other questions? 

Please send an email inquiry to us at


Application Questions: Please email us at

Research Questions: An SAO scientist is available online to answer your inquiries related to proposed research projects as well as current CfA programs at:


The significant access to a large optical telescopes and rich opportunities for collaboration with CfA colleagues were of great benefit to my efforts to develop and diversity my research portfolio as a Clay Fellow.
- Kate Rubin, 2013 Clay Fellow