Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. 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"

36276 results found.

  1. GRB 241104A : Detection and localization by SVOM/ECLAIRs
  2. GRB 240821A: further radio observations with the VLA
  3. Fermi GRB 241104A: Global MASTER-Net observations report
  4. GRB 241104A: Fermi GBM Final Real-time Localization
  5. GRB 241030A: GRBAlpha detection
  6. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  7. GRB 241030A: Rapid release of TESS data.
  8. GRB 241029A: GRBAlpha detection
  9. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  10. Swift GRB 241101A: Global MASTER-Net observations report
  11. GRB 241101A: FRAM-ORM optical limit
  12. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  13. EP241021a: Upper limit from Konus-Wind observations
  14. GRB 241101A: Swift-BAT refined analysis
  15. GRB 241030A: further SAO RAS optical observations
  16. GRB 241030A: Optical Observations via Virtual Telescope Project
  17. GRB 241030B: Swift-XRT refined Analysis
  18. GRB 241026A: SAO RAS optical observations
  19. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  20. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  21. GRB 241101A: Swift detection of a burst
  22. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits (duplicate submission of 38023)
  23. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  24. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  25. GRB 241030B: Montarrenti Observatory optical upper limit
  26. GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
  27. GRB 241030A: SAO RAS optical observations
  28. GRB 241030A: Fermi GBM Observation
  29. GRB 241030B : GIT optical upper limits
  30. GRB 241030B: LCOGT Optical Upper Limits
  31. GRB 241030B: Swift-BAT refined analysis
  32. GRB 241030A: Swift-BAT refined analysis
  33. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  34. GRB 241030B: Swift/UVOT Detection
  35. GRB 241029A: LCO optical detection
  36. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  37. GRB 241030B: SVOM/GRM observation
  38. GRB 241030B : MITSuME Akeno optical upper limits
  39. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  40. GRB 241030B: SVOM/VT optical afterglow observations
  41. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  42. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  43. GRB241030B: Fermi GBM Observation
  44. GRB 241030B: BTA observations
  45. GRB 241029A: SVOM/VT optical afterglow observations
  46. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  47. GRB 241030B: Enhanced Swift-XRT position
  48. GRB 241030B: optical observations from the INAF Asiago Observatory
  49. GRB241030B: GRANDMA/TAROT Upper Limit
  50. GRB 241030A: Swift-XRT refined Analysis
  51. GRB 241030B: SAO RAS optical observations
  52. GRB 241030B: AKO Optical Afterglow Detection
  53. GRB 241030B: Nanshan/HMT optical afterglow detection
  54. GRB 241030B: SVOM/ECLAIRs detection of a burst
  55. GRB 241030B: Prompt enhanced Swift-XRT position
  56. Konus-Wind detection of GRB 241030A
  57. GRB 241030B: Swift detection of a burst
  58. GRB 241030B: Fermi GBM Final Real-time Localization
  59. GRB 241030A: Fermi-LAT detection
  60. GRB 240912A: radio detection with the VLA
  61. Fermi GRB 241030A: Global MASTER-Net observations report
  62. GRB 241030A: AKO Optical Afterglow Detection
  63. Swift GRB 241030A: Global MASTER-Net observations report
  64. GRB 241030A: Swift/UVOT Detection
  65. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  66. GRB 241030A: SVOM/GRM observation
  67. GRB 241026A: Swift-BAT refined analysis
  68. GRB 241030A: SVOM/C-GFT optical observations
  69. GRB 241026A: LBT optical observations
  70. GRB 241030A: Multiband optical detection with Mephisto
  71. GRB 241030A: SVOM/VT optical afterglow observations
  72. GRB 241025A: The discovery of a BdHN I from data of Swift, Fermi, SVOM and Einstein Probe telescopes
  73. GRB 241030A : MITSuME Akeno optical afterglow detection
  74. GRB 241030A: Enhanced Swift-XRT position
  75. GRB 241029A: GROWTH-India Telescope optical follow up
  76. GRB 241030A: TRT optical observations
  77. GRB 241030A: Keck/LRIS spectroscopic redshift z = 1.411
  78. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  79. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  80. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  81. GRB 241030A: Fermi GBM Final Real-time Localization
  82. GRB 241029A: SAO RAS optical observations
  83. GRB 241026A: SAO RAS optical observations
  84. EP240919a / GRB 240919A: ATCA Detection of Radio Counterpart
  85. EP241021a: SAO RAS observations of rebrightening
  86. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  87. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  88. GRB 241026A: Swift/UVOT Upper Limits
  89. GRB 241029A: Swift-XRT observations
  90. GRB 241029A: Fermi GBM Observation
  91. GRB 241029A: AKO Optical Afterglow Detection
  92. GRB 241029A: GOTO optical afterglow detection
  93. GRB 241029A: MASTER early optical counterpart detection
  94. GRB 241029A: Xinglong-2.16m optical afterglow confirmation
  95. GRB 241029A: Mephisto observations
  96. EP 241026b: LBT possible optical counterpart (brightening source)
  97. GRB 241029A: TRT optical afterglow candidate detection
  98. GRB 241029A: Swift ToO observations
  99. GRB 241029A: SVOM/GRM observation
  100. GRB 241029A : Detection and localization of a bright long GRB by SVOM/ECLAIRs

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