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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.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
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"

66 results found.

  1. GRB 251214A: AstroSat CZTI detection
  2. EP251212a / GRB 251212A: AstroSat CZTI detection
  3. GRB 251113A: AstroSat CZTI detection
  4. GRB 251031A: Swift/BAT-GUANO localization skymap of a burst
  5. GRB 251001B: Swift/UVOT Detection
  6. GRB 250914A: AstroSat CZTI detection
  7. Fermi GRB 250909A: Global MASTER-Net observations report
  8. EP detected a brightening of LMXB 1ES 1735-26.9
  9. GRB 250807A: AstroSat CZTI detection of bright long burst
  10. GRB 250620C: AstroSat CZTI detection
  11. Swift GRB250101.56: Global MASTER-Net observations report
  12. Fermi trigger No 756678579: Global MASTER-Net observations report
  13. LIGO/Virgo/KAGRA S241129aa: Updated Sky localization
  14. Fermi trigger No 753166198: Global MASTER-Net observations report
  15. Fermi GRB 240814C: Global MASTER-Net observations report
  16. GRB 240805A: Swift/UVOT Upper Limits
  17. Fermi trigger No 740430582: Global MASTER-Net observations report
  18. Fermi GRB 240610A: Global MASTER-Net observations report
  19. Fermi GRB 240118B: Global MASTER-Net observations report
  20. Fermi trigger No 723149952: Global MASTER-Net observations report
  21. Fermi GRB 231114A: Global MASTER-Net observations report
  22. GRB 230812B: Iota Scorpii Observatory, La Spezia, Italy
  23. LIGO/Virgo S230524b: Global MASTER-Net observations report
  24. GRB 230328B NUTTelA-TAO / BSTI Early Measurements
  25. GRB 230322B: Swift/UVOT Detection
  26. Fermi trigger No 697678542: Global MASTER-Net observations report
  27. Swift GRB221202.84: Global MASTER-Net observations report
  28. GRB 211229A: Swift/BAT-GUANO arcminute localization
  29. Integral GRB210829.14: Global MASTER-Net observations report
  30. Fermi trigger No 649072251: Global MASTER-Net observations report
  31. Swift GRB210619.99: Global MASTER-Net observations report
  32. Fermi trigger No 641601187: Global MASTER-Net observations report
  33. Fermi GRB 201208A: Global MASTER-Net observations report
  34. Fermi trigger No 625695596: Global MASTER-Net observations report
  35. Fermi GRB 200908A: Global MASTER-Net observations report
  36. Konus-Wind detection of GRB 200729A
  37. IceCube Alert 200410.97: Global MASTER-Net observations report
  38. LIGO/Virgo S190910d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  39. LIGO/Virgo S190901ap : No significant candidates in TAROT-GRANDMA
  40. Swift GRB190631. Global MASTER-Net observations report
  41. Swift GRB190624.86 Global MASTER-Net observations report
  42. LIGO/Virgo S190510g: Potential host galaxies from the GLADE catalog
  43. LIGO/Virgo S190510g: Identification of a GW compact binary merger candidate
  44. GRB 180925A: Swift/UVOT Detection
  45. GRB 180115A: Swift-XRT refined Analysis
  46. GRB 170912B: Swift/UVOT Upper Limits
  47. Konus-Wind observation of GRB 170708A
  48. GRB 170311A: Swift/UVOT Upper Limits
  49. GRB 161007A: Swift/UVOT Upper Limits
  50. GRB 160313A: TAROT Calern observatory optical observations
  51. GRB 160104A: Swift-XRT refined Analysis
  52. LIGO/Virgo G194575: INAF-TNG spectra of LSQ15bjb
  53. GRB 140606A: Swift/UVOT Upper Limits
  54. GRB 131127A: Swift/UVOT Upper Limits
  55. GRB 130626A: Swift-XRT possible detection and UVOT upper limits
  56. GRB 120728A: Swift/UVOT Upper Limits
  57. GRB 120711A: Swift-XRT observations
  58. GRB 100625A: Swift/UVOT Upper Limits
  59. GRB091208B: Swift/UVOT refined analysis
  60. GRB090313: radio detection with the VLA
  61. GRB 080325: Swift/UVOT Upper Limits
  62. Transient in NGC 2770: spectroscopic evidence for a SN
  63. GRB 060218/SN 2006aj, high resolution spectra
  64. GRB050726: Swift UVOT observations
  65. IPN triangulation of GRB021223 (two large error boxes)
  66. SN2002ap (SN/GRB?) Echelle spectra

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