Palomar Observatory

08/22/2026

This August, representatives of the Palomar Observatory joined fellow members of the Alliance of Historic Observatories (AHO) in Spain and France for the Alliance’s 2026 General Assembly.

We began in Zaragoza, Spain, where we gathered to experience a total solar eclipse together. We were warmly welcomed by the people of Zaragoza and grateful to the local authorities for making such a memorable day possible.

From there, the group traveled into the French Pyrenees for the General Assembly at the historic Pic du Midi Observatory—one of the world’s great mountain observatories and a remarkable place to reflect on the long history of astronomical discovery.

Being part of the AHO means being part of a community that looks beyond individual observatories. Across countries and generations, these institutions share a common challenge and a common purpose: keeping astronomy alive—not only as a scientific endeavor, but as a living heritage that can continue to inspire future generations.

For Palomar, it is a privilege to stand alongside observatories that have been opening windows onto the universe for generations, and to help build the connections that will carry that legacy forward.

A heartfelt thank you to our hosts and friends in Spain and France for their extraordinary hospitality. We return home with new friendships, new ideas, and a renewed appreciation for the remarkable observatories that make up this international community.

08/12/2026

Palomar Observatory is excited to announce it is releasing its new Hale Telescope workhorse optical spectrograph, the Next Generation Palomar Spectrograph (NGPS) into facility status and facility service for members of the Palomar community.

NGPS is a state-of-the-art high-efficiency / moderate-dispersion (R ~ 4000) spectrograph covering 305 – 1040 nm. The NGPS optical design leverages Volume Phase Holographic (VPH) gratings to realize exceptional sky-to-detector throughput, and a high level of automated observing control; both of these advances enhance the science performance of the venerable Hale Telescope. Dedicated in 1948, the Hale continues to be a highly-productive telescope competitive with larger and newer facilities because of advances in available instrumentation such as NGPS.

With this facility status declaration a significant amount of guaranteed Hale telescope time is released to the NGPS development team over the next five years. The broader international Palomar community are the beneficiaries of this new instrument and the competitive capabilities it brings to all facets of the Palomar science portfolio.

The NGPS Development Team gratefully acknowledges support from all of our partners.

Ref:

Previous Caltech News Announcement of NGPS first light:

https://www.caltech.edu/about/news/palomar-observatory-produces-new-and-improved-rainbows-for-astronomers

NGPS Technical Specifications
https://caltechopticalobservatories.github.io/NGPS/technical-specifications.html

08/08/2026

08/04/2026

Behind every gleaming mirror is a great deal of careful preparation!

Recently, our team removed the 15-ton vacuum chamber ("bell jar") used to aluminize the 200-inch Hale Telescope mirror for routine maintenance. The work included inspecting O-rings and seals, replacing the used filaments with new ones, and preparing the system for its next use.

It takes 360 filaments to deposit the mirror's ultra-thin aluminum coating—and every single one is made in-house at Palomar Observatory. We prepare three complete sets (1,080 filaments total): one for a test firing, one for the actual mirror coating, and one spare set, just in case.

Before the mirror is ever coated, the entire system undergoes a full test fire to verify that everything is working properly and will produce the highly reflective surface astronomers depend on.

The massive bell jar is lifted using the observatory's 40-ton bridge crane. The Hale Telescope's next scheduled mirror aluminizing is planned for November 2027, part of the regular maintenance performed every two years.

Many thanks to our dedicated staff for the expertise and care that keep one of the world's most iconic telescopes performing at its best!

All images courtesy of Drew Roderick.

07/31/2026

The observatory will be closed to the public Saturday 8/1 and Sunday 8/2 due to a private event. We regret any inconvenience.

07/31/2026

A remarkable discovery with a Palomar connection!

Astronomers have found the strongest evidence yet for a "wandering" supermassive black hole—one located far from the center of its host galaxy. Normally invisible, it revealed itself when it tore apart and consumed an unlucky star in a brilliant flash of light known as a tidal disruption event.

The discovery began with observations from the Zwicky Transient Facility (ZTF) on Palomar's 48-inch Samuel Oschin Telescope. Researchers then used artificial intelligence to identify the event among the hundreds of thousands of celestial transients detected by ZTF, opening an exciting new way to search for these elusive cosmic giants.

Learn more about this discovery from the ZTF website below:

The image on the left is an artist impression of a tidal disruption event when a balck hole (usually in the center of a galaxy) swallows a star that has ventured too close to it. As the black hole devours the star, some of its material is stripped away and sent out producing some of the brightest ev...

07/29/2026

On sky now! We are proud to say that we have had over 1,100 people look through our new solar telescope since June 11th when it saw first light! We have been busy training our docents to educate visitors about our nearest star, our sun! Now visitors can look through the eyepiece of our new 100mm Lunt solar telescope stationed outside the museum. If there is a small line, stop by the table next to the solar telescope to see sun spots using the mobile Sunspotter!

**Since our docents are eagerly training to help better serve our visitors, solar telescope eyepiece viewing might not be available on all weekends.**

1) Solar docent, Ed Rumsey, assisting visitors as they look through the eyepiece.

2) Mobile Sunspotter

3) Sunspotter projecting an image of the Sun with sunspots onto a white background.