Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

21110 results found.

  1. GRB 220810A: Further Swift-XRT observations
  2. Swift GRB 220813A: Global MASTER-Net observations report
  3. GRB 220810A: Swift-XRT observations
  4. Fermi trigger No 681998863: Global MASTER-Net observations report
  5. GRB 220810A: Swift ToO observations
  6. GRB 220810A: MeerLICHT detection of two afterglow candidates
  7. Fermi trigger No 681890304: Global MASTER-Net observations report
  8. Fermi GRB 220810A: Global MASTER-Net observations report
  9. GRB 220627A: MeerKAT radio observations
  10. Fermi trigger No 681719116: Global MASTER-Net observations report
  11. Fermi trigger No 681633544: Global MASTER-Net observations report
  12. IceCube Alert 220808.33: Global MASTER-Net observations report
  13. Swift GRB220806.76: Global MASTER-Net observations report
  14. Fermi trigger No 681271717: Global MASTER-Net observations report
  15. Fermi trigger No 681212354: Global MASTER-Net observations report
  16. GRB 220730A: Swift-XRT afterglow detection
  17. GRB 220730A: Swift/UVOT Upper Limits
  18. GRB 220730A: Swift-XRT observations
  19. Swift GRB 220730A: Global MASTER-Net observations report
  20. Fermi trigger No 680782656: Global MASTER-Net observations report
  21. Fermi GRB 220728A: Global MASTER-Net observations report
  22. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220728A
  23. Fermi trigger No 680421061: Global MASTER-Net observations report
  24. Fermi GRB 220724A: Global MASTER-Net observations report
  25. Fermi GRB 220721A: Global MASTER-Net observations report
  26. GRB220714B: UVOT detections
  27. GRB 220715B: Swift/UVOT Upper Limits
  28. Swift GRB 220715B: Global MASTER-Net observations report
  29. GRB 220714B: LCO Optical Observations
  30. GRB 220710A: Swift/UVOT Upper Limits
  31. Retraction of GRB 220711B: 10.4 m GTC(+EMIR) observations (GCN 32387)
  32. GRB 220711B: 10.4 m GTC(+EMIR) observations
  33. GRB 220711B: 10.4 m GTC(+EMIR) observations
  34. GRB 220710A: Swift-XRT afterglow detection
  35. GRB 220711B, GROND observations
  36. GRB 220711B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  37. GRB 220711B: GIT optical upper limits
  38. Fermi trigger No 679248723: Global MASTER-Net observations report
  39. Fermi GRB 220711B: Global MASTER-Net observations report
  40. GRB 220712B: NOT optical afterglow confirmation
  41. GRB 220710A: Swift ToO observations
  42. GRB 220710A: Swift/BAT-GUANO arcminute localization
  43. GRB 220711B: Swift/UVOT Upper Limits
  44. GRB 220711B: NOT optical observations
  45. GRB 220708B: GIT optical upper limits
  46. IceCube-220624A: Classification of AT2022nit as a type Ia supernova and AT2021bei as an AGN
  47. GRB 220708A: Swift/UVOT Upper Limits
  48. GRB 220706A : NICER detection of re-brightening 1 day after the Swift trigger
  49. GRB 220706A: Swift/UVOT Upper Limits
  50. GRB 220708B: Swift-XRT afterglow detection
  51. GRB 220708B: Swift ToO observations
  52. GRB 220708B: Swift/BAT-GUANO arcminute localization
  53. GRB 220708A: Swift-XRT observations
  54. GRB 220627A: ATCA detection of radio counterpart
  55. GRB 220706A, GROND observations
  56. GRB 220706A: Optical observations from NOT
  57. GRB 220706A: MAXI/GSC detection 84 minutes after the Swift Trigger
  58. MAXI GRB220706.73: Global MASTER-Net observations report
  59. Swift GRB 220706A: Global MASTER-Net observations report
  60. GRB 220706A: Zadko observatory - Gingin optical observations
  61. Fermi trigger No 678635286: Global MASTER-Net observations report
  62. Alert from the HAWC Burst Monitor HAWC-220702A
  63. GRB 220701A: Swift/UVOT Upper Limits
  64. GRB 220701A: Lowell Discovery Telescope Optical Observations
  65. GRB 200701A: KAIT Optical Upper Limit
  66. Fermi-LAT Gamma-ray Observations of IceCube-220629A
  67. GRB 220627A, GROND observations
  68. GRB 220627A: Swift/UVOT Upper Limits
  69. Fermi-LAT Gamma-ray Observations of IceCube-220627A
  70. IceCube Alert 220629.99: Global MASTER-Net observations report
  71. GRB 220627A: Swift-XRT afterglow detection
  72. Trigger 1113743: Swift detection of MAXI J0655-013
  73. IceCube-220624A: One Candidate Counterpart from Swift/XRT follow up observations
  74. GRB 220627A: VLT MUSE redshift
  75. Swift XRT observations of WISEA J145820.77+412101.9 / IceCube 220624A
  76. GRB 220627A: MeerLICHT candidate optical afterglow
  77. Fermi-LAT Gamma-ray Observations of IceCube-220624A and and detection of a new gamma-ray source, Fermi J1458.0+4119
  78. GRB 220627A: Swift ToO observations
  79. Fermi trigger No 678058621: Global MASTER-Net observations report
  80. GRB 220627A: MeerLICHT detection of two afterglow candidates
  81. Fermi GRB 220627A: Global MASTER-Net observations report
  82. IceCube Alert 220627.74: Global MASTER-Net observations report
  83. GRB 220623A: GIT optical upper limits.
  84. IceCube-220624A: No Candidate Counterparts from the Zwicky Transient Facility
  85. Fermi GRB 220623B: Global MASTER-Net observations report
  86. Fermi GRB 220624A: Global MASTER-Net observations report
  87. IceCube Alert 220624.68: Global MASTER-Net observations report
  88. GRB 220611A: X-ray afterglow Chandra sub-arcsecond localization
  89. GRB 220623A: NOT optical observations
  90. GRB 220623A: Swift/UVOT Upper Limits
  91. GRB 220623A: BOOTES-5/JGT optical afterglow detection
  92. GRB 220623A: Swift-XRT observations
  93. Fermi trigger No 677597318: Global MASTER-Net observations report
  94. Fermi trigger No 677377371: Global MASTER-Net observations report
  95. Fermi GRB 220620B: Global MASTER-Net observations report
  96. Fermi GRB 220620A: Global MASTER-Net observations report
  97. Integral GRB220619.53: Global MASTER-Net observations report
  98. Swift GRB220620.02: Global MASTER-Net observations report
  99. GRB 220611A: Continued Gemini Infrared Observations
  100. GRB 220617A: TNG optical observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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