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"19565 results found.
- LIGO/Virgo G184098: MWA Followup
- LIGO/Virgo G184098: DESGW followup program
- LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
- LIGO/Virgo G184098: Fermi-GBM ground-based follow-up
- LIGO/Virgo G184098: Observations from the TOROS collaboration
- LIGO/Virgo G184098: observations by MASTER
- LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
- LIGO/Virgo G184098: Swift follow-up observations
- LIGO/Virgo G184098: Burst candidate in LIGO engineering run data
- GRB 150915A: Swift-XRT refined Analysis
- GRB 150910A: AAO optical observations
- GRB150915A : IRSF NIR upper limits
- GRB 150915A: NOT observations of a brightening afterglow
- GRB 150915A: Swift UVOT upper limits
- GRB 150910A: Mt. Terskol observatory optical observations
- GRB 150910A: TSHAO optical observations
- GRB 150915A: GROND detection of an optical counterpart candidate
- GRB 150915A: Swift detection of a burst
- GRB 150910A: T100 observations
- GRB 150911A: GROND Upper Limits
- GRB 150910A: Continued RATIR Observations
- GRB 150907A: Swift-XRT afterglow detection
- GRB 150912A: Swift-XRT and UVOT observations
- GRB 150911A: Chuguev observatory upper limit
- GRB 150911A: Mt. Terskol observatory upper limit
- GRB 150911A: Khureltogot upper limit
- GRB 150910A: Mt. Terskol observatory optical observation
- GRB 150912A: MITSuME Ishigakijima upper limits
- GRB 150910A: RATIR Observations
- GRB 150910A: MITSuME Ishigakijima Optical Observation after 2 days
- GRB 150912A: Swift ToO observations
- GRB 150911A: Swift/UVOT Upper Limits
- GRB 150910A: AAO optical observations
- GRB 150910A: MITSuME Ishigakijima Optical Observation after 1 day
- GRB 150910A: Chuguev observatory optical observations
- GRB 150911A: MITSuME Okayama upper limits
- GRB 150910A: continued SAO RAS optical observations
- GRB 150911A: Enhanced Swift-XRT position
- GRB150911A MITSuME Okayama Ks-band upper-limit
- GRB 150910A: TSHAO optical observations
- GRB 150911A: Swift detection of a burst
- GRB 150910A: NOT observations of the afterglow
- GRB 150910A: MITSuME Okayama Ks-band Observation
- GRB 150910A: GROND observation of the afterglow
- GRB 150910A: MITSuME Ishigakijima Optical Observation
- GRB 150910A: SAO RAS optical photometry
- GRB 150910A: Enhanced Swift-XRT position
- GRB 150910A: Swift/UVOT Detection of a Brightening Afterglow
- GRB 150910A: Nanshan optical observations
- GRB 150910A: MITSuME Okayama Optical Observation
- GRB 150910A: Swift detection of a burst with an optical afterglow
- Fermi GBM trigger 463422723/150908689 is not a GRB
- IPN Triangulation of GRB 150906B (short/intense)
- GRB150907A: Swift/UVOT observations
- GRB 150907B: Enhanced Swift-XRT position
- GRB 150907B: GROND Upper Limits
- GRB 150907B: Swift-XRT observations
- GRB 150907A: Tiled Swift observations
- GRB 150906A: Fermi GBM detection
- GRB 150818A: TSHAO and SAO RAS optical observations
- GRB 150902A: Swift-XRT afterglow detection
- ANTARES neutrino detection: ANU 2.3m and Kepler K2 Observations of the Swift x-ray source
- GRB 150902A: Swift/UVOT Upper Limits
- GRB 150831A: 9.8 GHz VLA upper limits
- GRB 150902A: Swift ToO observations
- GRB 150831B: Swift/UVOT Upper Limits
- GRB 150831B: Swift-BAT refined analysis
- GRB 150831A: GROND Upper Limits
- GRB 150831A: Swift/UVOT Upper Limits
- GRB 150831B: Swift-XRT observations
- GRB 150831A: Swift-XRT refined Analysis
- GRB 150831A: Swift-BAT refined analysis
- GRB 150831A: Enhanced Swift-XRT position
- GRB 150831A: optical upper limit ISON-SSO
- GRB 150831A: Swift detection of a short burst
- GRB 150821A, Swift-BAT refined analysis
- GRB 150821A: GROND afterglow observations
- GRB 150821A: Swift-XRT refined Analysis
- GRB 150819A: Mondy and TSHAO optical upper limits
- GRB 150821A: Swift/UVOT Detection
- GRB 150821A: Enhanced Swift-XRT position
- GRB 150821A: Swift detection of a burst with an optical afterglow
- GRB150819A: NOT imaging
- GRB 150818A: Continued NOT monitoring - afterglow confirmation
- GRB 150818A: Mondy optical observations
- GRB 150818A: MITSuME Ishigakijima upper limits
- GRB 150819A: RATIR Optical Observations
- GRB 150819A: Swift-BAT refined analysis
- GRB 150819A: Swift/UVOT Upper Limits
- GRB 150819A: Enhanced Swift-XRT position
- GRB150818A: NOT imaging
- GRB 150819A: Swift detection of a burst
- GRB 150818A: Swift/UVOT Detection
- GRB 150817A: AAO optical observations
- GRB 150818A: Enhanced Swift-XRT position
- GRB 150817A: Continued RATIR Optical Observations - Afterglow Confirmation
- GRB 150818A: Swift detection of a burst
- GRB 150817A: Swift/UVOT Upper Limits
- GRB 150817A: Enhanced Swift-XRT position
- GRB 150817A: Continued RATIR Observations, Revised Candidate