Nordic Optical Telescope

24/04/2026

Today at our office, we had the pleasure of hosting a talk by Håkon Dahle from the Institute of Theoretical Astrophysics, University of Oslo, titled:

“𝑻𝒊𝒎𝒆-𝒅𝒆𝒍𝒂𝒚 𝒄𝒐𝒔𝒎𝒐𝒍𝒐𝒈𝒚 𝒂𝒏𝒅 𝒒𝒖𝒂𝒔𝒂𝒓 𝒑𝒉𝒚𝒔𝒊𝒄𝒔 𝒘𝒊𝒕𝒉 𝑵𝑶𝑻 𝒂𝒏𝒅 𝑱𝑾𝑺𝑻”

The talk explored how strongly gravitationally lensed quasars can help address one of the most intriguing questions in modern cosmology: the Hubble tension, the discrepancy between early-Universe and late-Universe measurements of the Hubble constant, H₀.

Håkon also presented recent results on wide-separation lensed quasars, where galaxy clusters act as natural cosmic telescopes, magnifying distant quasars and their host galaxies. He discussed recent discoveries of these systems, time-delay measurements with the Nordic Optical Telescope, and follow-up observations with Hubble Space Telescope and James Webb Space Telescope.

Many thanks to Håkon for an inspiring presentation and to everyone who joined the discussion!

23/04/2026

📢 The Nordic Optical Telescope invites applications for observing time in 𝗣𝗲𝗿𝗶𝗼𝗱 𝟳𝟰, 𝗢𝗰𝘁𝗼𝗯𝗲𝗿 𝟭, 𝟮𝟬𝟮𝟲 - 𝗔𝗽𝗿𝗶𝗹 𝟭, 𝟮𝟬𝟮𝟳 📢

⏳ The deadline for receipt of the applications is 𝗠𝗼𝗻𝗱𝗮𝘆, 𝗠𝗮𝘆 𝟭𝟴, 𝟮𝟬𝟮𝟲, 𝗮𝘁 𝗨𝗧 𝟭𝟮:𝟬𝟬 𝗻𝗼𝗼𝗻.

In relation to the call for proposals, the following:
✔️ The 𝑅𝑎𝑝𝑖𝑑-𝑟𝑒𝑠𝑝𝑜𝑛𝑠𝑒 𝑚𝑜𝑑𝑒 (RRM) has now been successfully used, and we continue to develop further functionality improvements. For P74 in particular, we offer the RRM mode for ALFOSC only: imaging or spectroscopy.
✔️ Some of the lowest-ranked service-mode programs, based on the scientific ratings given by the OPC, will be given a '𝐹𝑖𝑙𝑙𝑒𝑟-𝑚𝑜𝑑𝑒' status and be executed in Queue-mode scheduling, but with low priority.
✔️ The double image polarimeter DIPol-UF remains available as a visitor instrument at the NOT. It allows for high-speed and high-precision broad-band polarimetry simultaneously in 3 pass-bands (BVR), but can also be used as a high-speed 3-band photometer. DIPol-UF is not a common-user instrument, but is only supported during specific periods. See for more information: https://www.not.iac.es/instruments/dipol-uf
✔️ The SOFIN high-resolution Echelle spectrograph is again available. It only is offered to do circular spectro-polarimetry with the medium-resolution (R~80,000) camera. SOFIN is not a common-user instrument: only limited support is provided.
✔️ Please contact our Director and the operations staff ([email protected]) well in advance of the application dead-line if you are making plans to use your own instrument at NOT.

You can find more information here: https://www.not.iac.es/observing/proposals

📷 Image credit & copyright: Urs Leutenegger

17/04/2026

Yesterday and today we participated in the 2nd edition of the Employment, Training, and Entrepreneurship Fair hosted by La Palma Empleo, from Cabildo de La Palma (the Island Council). We shared a booth with our colleagues from Gran Telescopio Canarias and the CTAO to showcase our work to the local community and inform them about the training and employment opportunities available at the observatory.

As you can see in the photos, the LEGO model of the NOT—our best ambassador—made a special appearance and was there as well. We loved spending time with the official representatives and the audience, and we hope everyone enjoyed the experience.

30/03/2026

📢 Nordic Optical Telescope schedule for period 73 (April 1, 2026 - October 1, 2026) released!

We wish a successful observing run to all of you.

https://www.not.iac.es/observing/schedules/

25/02/2026

🎓 Since 2018, we have been hosting Vocational Education and Training (VET) students — known as Formación Profesional in Spanish — from Departamento Informática y Comunicaciones IES José María Pérez Pulido for internships at our telescope. In addition, thanks to the institute's participation in the Erasmus+ programme, some of them have done their internships at Aarhus Universitet.

🗞️ Last weekend, several media on La Palma reported on the students' experiences in their pages, for which we are grateful to El Apurón, El Time and La Palma Ahora.com for their coverage.

🤩 From the Nordic Optical Telescope, we are very happy to continue with this action that brings mutual benefit to both parties, as not only do the students have the opportunity to develop technical tasks in an international environment (which is not always easy from a small and outermost island like La Palma), but these tasks have had a real, positive and measurable impact on the operation of the telescope.

El NOT, situado en el Observatorio del Roque de Los Muchachos, mantiene desde 2018 un convenio con el Instituto de Educación Secundaria ubicado en Los Llanos de Aridane a través de la Universidad de Aarhus (Dinamarca), una de las dos instituciones propietarias del telescopio junto con la Universid...

12/02/2026

🌍 The call for International Time Programme (ITP) proposals in semesters 2026B and 2027A (covering the periods October 1, 2026 – April 1, 2027 and April 1, 2027 – October 1, 2027 for the Nordic Optical Telescope) has been opened.

🔭 This programme makes up to 5% of the available observing time on participating telescopes at the Roque de los Muchachos and Teide observatories and is open to all research organisations worldwide.

🔎 For the details of the announcement, see the International Scientific Committee (CCI) call for proposals. You are reminded that Principal Investigators 𝗠𝗨𝗦𝗧 be based in one of the seven signatory European countries (🇧🇪 🇫🇮 🇫🇷 🇩🇪 🇮🇹 🇪🇸 🇬🇧), with teams representing at least three of them.

⏳ The deadline for receipt of applications is 𝗠𝗼𝗻𝗱𝗮𝘆, 𝗠𝗮𝗿𝗰𝗵 𝟵, 𝟮𝟬𝟮𝟲, 𝗮𝘁 𝟮𝟯:𝟱𝟵 𝗨𝗧. More detailed information can be found at the following link: https://www.iac.es/en/observatorios-de-canarias/international-scientific-committee

📷 Image credit & copyright: Urs Leutenegger

24/12/2025

🤩 Light painting using a telescope! This year, the NOT staff would like to wish you a Merry Christmas by sharing this artistic image created by Roar Holmberg.

🎄 This image was obtained by moving the telescope in the shape of a tree while exposing a field of stars and then stopping at the top to draw the star. In fact, these Christmas trees are probably the only ones in the world where the stars at the top are actually stars.

💫 glædelig jul - hyvää joulua - gleðileg jól - god jul - god Jul 💫

15/12/2025

🤩 The Nordic Optical Telescope has contributed its observations to a milestone: the first ever spatially resolved, gravitationally lensed superluminous supernova, SN 2025wny. Early ALFOSC spectroscopy of this extraordinary transient confirmed that it was a supernova at an incredible distance, whose light has travelled almost 10 billion years to reach us, meaning that when that light was emitted, the Universe was “only” about 4 billion years old.

🔭 This discovery, led by Joel Johansson of the Oskar Klein Centre (OKC) at Stockholm University and carried out by an international research team, includes among its first authors Ariel Goobar (OKC) and Dan Perley and Jacob Wise of Liverpool John Moores University (LJMU). This also highlights the power of coordinated follow-up: while the NOT spectra identified the event as a supernova, our neighbours across the hill at the observatory, the Liverpool Telescope (LT), provided crucial images that resolved four separate images of SN 2025wny, a stunning demonstration of the gravitational lensing effect in action.

🧐 See the press release here: https://www.su.se/english/news/articles/2025-12-12-astronomers-discover-the-first-gravitationally-lensed-superluminous-supernova

20/11/2025

📰 A paper resulting from the NOT Summer School has been published in Astronomy & Astrophysics, led by Casper Christian Pedersen from AAU Materialer og Produktion. During the August 2024 summer school, the team obtained phase-resolved optical spectroscopy and R- and B-band photometry of the white dwarf candidate ZTF 1851+1714. These observations represent the first spectroscopic data of this object reported in the scientific literature.

👩‍🎓👨‍🎓 This shows that the courses hosted at the NOT—both on-site and remote—are far more than entertainment for astrophysics students: while gaining hands-on experience, often for the first time in their lives with a professional telescope, they are simultaneously generating science of publishable quality.

🧐 See the paper here:

Astronomy & Astrophysics (A&A) is an international journal which publishes papers on all aspects of astronomy and astrophysics

06/11/2025

🤔 Any plans for this weekend? Submitting a proposal for the next observation period seems like a great plan, doesn't it?

⌛️ Remember that the deadline is next Monday, November 10, 2025, at 12 UT.