Skip to main content
New! BOOM Notices and Schema v7.0.0. See news and announcements

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"

3031 results found.

  1. Fermi trigger No 679248723: Global MASTER-Net observations report
  2. Fermi GRB 220711B: Global MASTER-Net observations report
  3. GRB 220702B: AstroSat CZTI detection
  4. GRB 220627A: Fermi GBM Detection of a possible Lensed or Ultra-long GRB
  5. Fermi trigger No 678058621: Global MASTER-Net observations report
  6. IceCube Alert 220627.74: Global MASTER-Net observations report
  7. IceCube-220624A: No Candidate Counterparts from the Zwicky Transient Facility
  8. Fermi GRB 220624A: Global MASTER-Net observations report
  9. IceCube Alert 220624.68: Global MASTER-Net observations report
  10. IPN triangulation of GRB 220624A
  11. GRB 220623A: BOOTES-5/JGT optical afterglow detection
  12. Fermi trigger No 677377371: Global MASTER-Net observations report
  13. Fermi GRB 220620A: Global MASTER-Net observations report
  14. GRB 220619A: AstroSat CZTI detection
  15. Fermi GRB 220617A: Global MASTER-Net observations report
  16. Fermi trigger No 676909037: Global MASTER-Net observations report
  17. MAXI GRB220607.31: Global MASTER-Net observations report
  18. MAXI GRB220607.41: Global MASTER-Net observations report
  19. Fermi trigger No 675992935: Global MASTER-Net observations report
  20. IPN triangulation of GRB 220528A (short)
  21. Fermi GRB 220530A: Global MASTER-Net observations report
  22. GRB 220528B: Swift/BAT-GUANO detection outside the coded FOV
  23. Fermi trigger No 675411172: Global MASTER-Net observations report
  24. IPN triangulation of GRB 220524B
  25. IPN triangulation of GRB 220522B
  26. GRB 220521A: classification and detection by SPI-ACS/INTEGRAL
  27. Fermi GRB 220518B: Global MASTER-Net observations report
  28. GRB 220518A: Swift/UVOT Detection
  29. GRB 220514A: MITSuME Akeno optical observation
  30. IceCube-220513A: No Candidate Counterparts from the Zwicky Transient Facility
  31. IceCube Alert 220513.97: Global MASTER-Net observations report
  32. Fermi GRB 220513A: Global MASTER-Net observations report
  33. GRB 220511A: Swift/BAT-GUANO arcminute localization
  34. Fermi trigger No 673846271: Global MASTER-Net observations report
  35. GRB 220506A: MITSuME Akeno optical upper limits
  36. GRB 220506A: GIT optical upper limit.
  37. GRB 220506A/MAXI J1558-266: MAXI/GSC detection
  38. IPN triangulation of GRB 220423A
  39. IceCube-220501A: No Candidate Counterparts from the Zwicky Transient Facility
  40. IceCube Alert 220501.95: Global MASTER-Net observations report
  41. GRB 220426A: Swift-XRT and UVOT observations
  42. Konus-Wind detection of GRB 220426A
  43. Fermi trigger No 672492774: Global MASTER-Net observations report
  44. GRB 220421B: Detection by VZLUSAT-2
  45. Fermi GRB 220417A: Global MASTER-Net observations report
  46. Fermi trigger No 671729344: Global MASTER-Net observations report
  47. GRB 220412A: Continued RATIR Observations and Steepening of the Light Curve
  48. GRB 220408A: KAIT Optical Observations
  49. GRB 220408A: Swift detection of a burst with an optical counterpart, possibly associated with M51
  50. IceCube-220405A: No Candidate Counterparts from the Zwicky Transient Facility
  51. IceCube-220405B: No Candidate Counterparts from the Zwicky Transient Facility
  52. GRB 220404A: Swift-BAT refined analysis
  53. GRB 220404B: Fermi GBM Final Real-time Localization
  54. GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
  55. Fermi GRB 220330A: Global MASTER-Net observations report
  56. GRB220319A: Optical observations from NOT
  57. IceCube-220317A: MASTER Global Robotic Net optical observations
  58. GRB 220315A: Fermi GBM Final Real-time Localization
  59. GRB 220308A: AGILE detection
  60. GRB 220310A: MAXI/GSC detection
  61. Fermi GRB 220309A: Global MASTER-Net observations report
  62. IPN triangulation of GRB 220305B
  63. Fermi trigger No 666962499: Global MASTER-Net observations report
  64. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory continued optical observations
  65. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory optical observations
  66. Fermi GRB 220209A: Global MASTER-Net observations report
  67. Konus-Wind detection of GRB 220128A
  68. Fermi GRB 220131A: Global MASTER-Net observations report
  69. GRB 220117C: Swift/BAT-GUANO arcminute localization
  70. Fermi trigger No 663966693: Global MASTER-Net observations report
  71. Fermi GRB 220111A: Global MASTER-Net observations report
  72. Fermi trigger No 663406755: Global MASTER-Net observations report
  73. GRB 220101A: TNG NIR afterglow detection
  74. Fermi trigger No 662768315: Global MASTER-Net observations report
  75. Fermi trigger No 662084433: Global MASTER-Net observations report
  76. GRB 211222A: Fermi GBM Final Real-time Localization
  77. GRB 211218A: MITSuME Akeno optical upper limits
  78. GRB 211106A: XMM-Newton monitoring campaign detections
  79. Fermi GRB 211216A: Global MASTER-Net observations report
  80. GRB 211211A: Further observations from CAFOS/2.2m CAHA
  81. Fermi GRB 211212B: Global MASTER-Net observations report
  82. Fermi GRB 211211B: Global MASTER-Net observations report
  83. Fermi trigger No 660868196: Global MASTER-Net observations report
  84. Fermi trigger No 660736561: Global MASTER-Net observations report
  85. Fermi GRB 211204C: Global MASTER-Net observations report
  86. GRB 211204C: Fermi GBM Final Real-time Localization
  87. Fermi GRB 211204B: Global MASTER-Net observations report
  88. GRB 211129A: Enhanced Swift-XRT position
  89. IPN triangulation of GRB 211118A
  90. GRB 211129A: Swift detection of a burst
  91. GRB 211120548: Fermi GBM observation
  92. IceCube Alert 211125.27: Global MASTER-Net observations report
  93. Fermi trigger No 659106591: Global MASTER-Net observations report
  94. Fermi trigger No 658971499: Global MASTER-Net observations report
  95. IceCube-211116A: No neutrino counterpart detected with ANTARES
  96. Fermi trigger No 658755664: Global MASTER-Net observations report
  97. Fermi trigger No 658764238: Global MASTER-Net observations report
  98. Fermi GRB 211112A: Global MASTER-Net observations report
  99. Fermi trigger No 658214822: Global MASTER-Net observations report
  100. GRB 211109B: Fermi GBM Final Real-time Localization

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov