GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"41698 results found.
- GRB 150818A: 10.4m GTC spectroscopy and host galaxy
- IPN Triangulation of GRB 150819B (short / very intense)
- GRB 150818A: Mondy optical observations
- GRB 150818A: MITSuME Ishigakijima upper limits
- GRB 150819A: RATIR Optical Observations
- GRB 150819A: Swift-XRT refined Analysis
- GRB 150818A: MITSuME Akeno optical upper limits
- GRB 150819A: Swift-BAT refined analysis
- GRB 150819A: MASTER-IAC early upper limit
- GRB 150819A: Swift/UVOT Upper Limits
- GRB 150818A: Swift-XRT update, correction to GCN 18162
- GRB150818A: NOT imaging
- GRB 150819A: Swift detection of a burst
- GRB 150818A: Swift-XRT refined Analysis
- GRB 150818A: Swift/UVOT Detection
- GRB 150817A: AAO optical observations
- GRB 150817A: LCOGT observations
- GRB 150818A: Swift-BAT refined analysis
- GRB 150817A: Continued RATIR Optical Observations - Afterglow Confirmation
- GRB 150818A: Swift/UVOT candidate afterglow
- GRB 150818A: Planned XMM-Newton observation
- GRB 150817A: P60 Observations
- GRB 150818A: Swift detection of a burst
- MASTER OT inside bright ESO240-010 galaxy detection during FERMI trigger GRB150816.83 inspection
- GRB 150817A: Swift/UVOT Upper Limits
- GRB 150817A: Fermi GBM observation
- GRB 150817A: Swift-BAT refined analysis
- GRB 150817A: Swift-XRT refined Analysis
- GRB 150817A: Continued RATIR Observations, Revised Candidate
- GRB 150817A: RATIR Optical Afterglow Candidate
- GRB 150817A: Swift detection of a burst
- Fermi GBM Trigger 150815694 is not a GRB
- GRB 150811A: Continued RATIR Observations
- GRB 150811A: Continued RATIR Observations
- GBM Trigger 150813665 is not a GRB
- Swift Trigger 652046 is a particle shower event
- Konus-Wind observation of GRB 150811B
- Swift Trigger 652046 is probably not a GRB
- GRB 150811A: KAIT Refined Analysis
- GRB 150811A: VLA Detection
- IPN Triangulation of GRB 150811B
- GRB 150811A: Continued RATIR Observations
- GRB 150811A: Swift/UVOT further observations
- GRB 150811B: Fermi GBM detection
- GRB 150811A: Swift-BAT refined analysis
- GRB 150811A: SAO RAS optical observations
- GRB 150811A: Swift-XRT refined Analysis
- GRB 150810A: Fermi GBM detection
- GRB 150811A: P60 Observations
- GRB 150811A: LCOGT-McDonald afterglow detection
- GRB 150811A: Swift/UVOT Detection
- GRB 150811A: KAIT optical candidate
- GRB 150811A: RATIR Optical Afterglow Detection
- GRB 150811A: Swift detection of a burst
- Fermi GBM GRB Trigger 460608875: iPTF P48 Observations
- Fermi GBM trigger 150807969 is not a GRB
- Fermi GBM trigger 150806450 is not a GRB
- GRB 150728A: TNG optical observations
- Fermi GBM trigger 150805556 is not a GRB
- GRB 150727A: IRSF NIR observation
- GRB 150801A: Swift-XRT observations
- GRB 150801B: Swift/UVOT Upper Limits
- GRB 150801B: Swift-BAT refined analysis
- GRB 150801B: Swift-XRT refined Analysis
- Fermi GBM triggers 150730606 150731173 and 150801590 are not due to GRBs
- Fermi GBM GRB Trigger 458852670: iPTF P48 Observations
- GRB 150721A (Fermi GBM Trigger 459150552): iPTF P48 Observations
- GRB 150801B: Swift detection of a burst
- GRB 150801A: Tiled Swift observations
- GRB 150801A: MAXI/GSC detection
- GRB 150724B: Swift-XRT afterglow detection
- GRB 150424A: HST imaging
- GRB150724B: Retraction of the uvot detection
- GRB 150728A: Continued RATIR Optical Observations
- GRB 150728A: TSHAO optical observations
- GRB 150728A: RATIR Optical Observations
- GRB 150727A: Continued RATIR Optical Observations - Fading
- GRB 150728A: AAO optical observations
- GRB 150728A: Swift-XRT refined Analysis
- GRB 150728A: Swift/UVOT Upper Limits
- GRB 150728A: Swift-BAT refined analysis
- GRB 150728A: FTN observations
- GRB 150727A: RATIR Optical Observations
- GRB 150728A: Swift detection of a GRB
- GRB 150727A: Swift-BAT refined analysis
- GRB 150727A: Watcher optical upper limit
- GRB 150727A: Swift/UVOT Detection
- GRB 150727A: LCOGT-Cerro Tololo observations
- GRB 150727A: Swift-XRT refined Analysis
- GRB 150727A: Fermi GBM detection
- GRB 150727A: VLT/X-shooter redshift
- GRB 150724B: Continued RATIR Optical Observations
- GRB 150724B: MASTER upper limit
- GRB 150727A: Swift detection of a burst with an optical counterpart
- GRB 150724B: Swift/UVOT Detection
- Konus-Wind observation of GRB 150724B
- Konus-Wind observation of GRB 150725A
- GRB 150724B: RATIR Optical Observations
- Swift 650221/IGR J00291+5934: Liverpool Telescope observations
- GRB 150724B: Swift-XRT observations