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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"

68 results found.

  1. EP detected a brightening of LMXB 1ES 1735-26.9
  2. GRB 260207B: AstroSat CZTI detection
  3. GRB 251214A: AstroSat CZTI detection
  4. EP251212a / GRB 251212A: AstroSat CZTI detection
  5. GRB 251113A: AstroSat CZTI detection
  6. GRB 251031A: Swift/BAT-GUANO localization skymap of a burst
  7. GRB 251001B: Swift/UVOT Detection
  8. GRB 250914A: AstroSat CZTI detection
  9. Fermi GRB 250909A: Global MASTER-Net observations report
  10. EP detected a brightening of LMXB 1ES 1735-26.9
  11. GRB 250807A: AstroSat CZTI detection of bright long burst
  12. GRB 250620C: AstroSat CZTI detection
  13. Swift GRB250101.56: Global MASTER-Net observations report
  14. Fermi trigger No 756678579: Global MASTER-Net observations report
  15. LIGO/Virgo/KAGRA S241129aa: Updated Sky localization
  16. Fermi trigger No 753166198: Global MASTER-Net observations report
  17. Fermi GRB 240814C: Global MASTER-Net observations report
  18. GRB 240805A: Swift/UVOT Upper Limits
  19. Fermi trigger No 740430582: Global MASTER-Net observations report
  20. Fermi GRB 240610A: Global MASTER-Net observations report
  21. Fermi GRB 240118B: Global MASTER-Net observations report
  22. Fermi trigger No 723149952: Global MASTER-Net observations report
  23. Fermi GRB 231114A: Global MASTER-Net observations report
  24. GRB 230812B: Iota Scorpii Observatory, La Spezia, Italy
  25. LIGO/Virgo S230524b: Global MASTER-Net observations report
  26. GRB 230328B NUTTelA-TAO / BSTI Early Measurements
  27. GRB 230322B: Swift/UVOT Detection
  28. Fermi trigger No 697678542: Global MASTER-Net observations report
  29. Swift GRB221202.84: Global MASTER-Net observations report
  30. GRB 211229A: Swift/BAT-GUANO arcminute localization
  31. Integral GRB210829.14: Global MASTER-Net observations report
  32. Fermi trigger No 649072251: Global MASTER-Net observations report
  33. Swift GRB210619.99: Global MASTER-Net observations report
  34. Fermi trigger No 641601187: Global MASTER-Net observations report
  35. Fermi GRB 201208A: Global MASTER-Net observations report
  36. Fermi trigger No 625695596: Global MASTER-Net observations report
  37. Fermi GRB 200908A: Global MASTER-Net observations report
  38. Konus-Wind detection of GRB 200729A
  39. IceCube Alert 200410.97: Global MASTER-Net observations report
  40. LIGO/Virgo S190910d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  41. LIGO/Virgo S190901ap : No significant candidates in TAROT-GRANDMA
  42. Swift GRB190631. Global MASTER-Net observations report
  43. Swift GRB190624.86 Global MASTER-Net observations report
  44. LIGO/Virgo S190510g: Potential host galaxies from the GLADE catalog
  45. LIGO/Virgo S190510g: Identification of a GW compact binary merger candidate
  46. GRB 180925A: Swift/UVOT Detection
  47. GRB 180115A: Swift-XRT refined Analysis
  48. GRB 170912B: Swift/UVOT Upper Limits
  49. Konus-Wind observation of GRB 170708A
  50. GRB 170311A: Swift/UVOT Upper Limits
  51. GRB 161007A: Swift/UVOT Upper Limits
  52. GRB 160313A: TAROT Calern observatory optical observations
  53. GRB 160104A: Swift-XRT refined Analysis
  54. LIGO/Virgo G194575: INAF-TNG spectra of LSQ15bjb
  55. GRB 140606A: Swift/UVOT Upper Limits
  56. GRB 131127A: Swift/UVOT Upper Limits
  57. GRB 130626A: Swift-XRT possible detection and UVOT upper limits
  58. GRB 120728A: Swift/UVOT Upper Limits
  59. GRB 120711A: Swift-XRT observations
  60. GRB 100625A: Swift/UVOT Upper Limits
  61. GRB091208B: Swift/UVOT refined analysis
  62. GRB090313: radio detection with the VLA
  63. GRB 080325: Swift/UVOT Upper Limits
  64. Transient in NGC 2770: spectroscopic evidence for a SN
  65. GRB 060218/SN 2006aj, high resolution spectra
  66. GRB050726: Swift UVOT observations
  67. IPN triangulation of GRB021223 (two large error boxes)
  68. SN2002ap (SN/GRB?) Echelle spectra

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