Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

20351 results found.

  1. GRB 090309: Swift/UVOT Upper Limits
  2. GRB 090309: Enhanced Swift-XRT position
  3. GRB 090308: GROND observations
  4. GRB 090308: Gemini GMOS Observations
  5. GRB 090309: Swift detection of a burst
  6. GRB 090308: Swift/UVOT Upper Limits
  7. GRB 090307: GROND Upper Limits
  8. GRB 090306B: GROND Upper Limits
  9. GRB 090308: Swift-XRT refined analysis
  10. GRB 090308: Swift detection of a burst
  11. GRB 090306B: Possible XRT afterglow
  12. GRB 090307: Swift-XRT afterglow confirmation and analysis
  13. Swift Trigger 345551 is probably not a GRB
  14. IPN localization of short GRB 090305C
  15. GRB 090306: Swift detection of a possible burst
  16. GRB 090305: Swift/UVOT Upper Limits
  17. GRB 090305: Swift-XRT refined analysis
  18. GRB090305: GMOS-S Candidate Optical Afterglow
  19. GRB 090305: Swift detection of a short burst
  20. Konus-Wind observation of bright short GRB 090227B
  21. Konus-Wind observation of GRB 090301A
  22. GRB 081211B: Nearby cluster
  23. Ongoing activity of AXP/SGR 1E1547.0-5408
  24. GRB090217: XRT analysis
  25. Konus-Wind observation of GRB 090217
  26. SGR activity seen by BAT during ICSP Ionospheric Events
  27. VLA radio upper limit on GRB 090205
  28. GRB 090205: Swift/UVOT Upper Limits
  29. GRB 090205: GROND observations and photometric redshift estimate
  30. GRB 090205: VLT candidate afterglow
  31. GRB 090205: Enhanced Swift-XRT position
  32. GRB 090205: Swift detection of a burst
  33. GRB090201: Swift UVOT upper limits
  34. GRB 090201: object inside the enhanced XRT error circle
  35. GRB 090201: Enhanced Swift-XRT position
  36. GRB 090201: VLT NIR observations
  37. GRB 090201: Swift-BAT refined analysis
  38. GRB 090201: VLT afterglow candidate
  39. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  40. GRB 090201: ROTSE-III Optical Limits
  41. GRB 090126A: Swift/UVOT Upper Limits
  42. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  43. Suzaku ToO Observation of AXP 1E 1547.0-5408
  44. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  45. GRB 090102: HST observations and host galaxy
  46. GRB 090118: no afterglow candidate
  47. GRB 090123: GROND detection
  48. GRB 090123: Swift/UVOT Observations
  49. GRB090123: Enhanced Swift-XRT position
  50. GRB 090123: Swift detection of a burst
  51. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  52. Trigger 340734: Swift detection of a possible short burst
  53. AXP 1E1547.0-5408 activity with SGR bursts
  54. GRB 090118: Subaru NIR Observation
  55. GRB 090118: KPNO 4m 2nd Epoch Observations
  56. GRB 090118 (BATSS): GRT Optical Observation
  57. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  58. GRB090118 Swift/UVOT upper limits
  59. GRB 090118: GROND Upper Limits
  60. GRB 090118: Possible burst detection from Swift-BAT slew data
  61. GRB 090117 - Fermi GBM Observations
  62. GRB 090117: GROND Upper Limits
  63. GRB090117 Swift/UVOT upper limits
  64. GRB090117: Swift-XRT detection of a possible candidate afterglow
  65. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  66. GRB 090113: Swift UVOT upper limits
  67. GRB 090113: GROND Upper Limits
  68. GRB 090113: Observations from NOT
  69. GRB 090113: Enhanced Swift-XRT position
  70. GRB 090113: ROTSE-III Optical Limits
  71. GRB 090113: Swift detection of a burst
  72. GRB 090112: Fermi GBM detection
  73. GRB 090111: Swift UVOT Upper Limits
  74. GRB 090111: Swift-XRT refined analysis
  75. GRB 090111: Enhanced Swift-XRT position
  76. GRB 090111: Swift detection of a burst
  77. GRB 090107B: Swift XRT afterglow confirmation
  78. GRB 090107B: Swift/UVOT Observations
  79. GRB 090107B: Swift-XRT detection of possible afterglow
  80. VLA radio upper limit on GRB 090102
  81. GRB 090102: GRT Optical Observation
  82. Swift triggered on the HMXB 1A 1118-61
  83. GRB 090102: P60 Imaging and P200 Spectroscopy
  84. GRB 090102 Observations from IAC80
  85. GRB 090102: GROND observations of the optical afterglow
  86. GRB 090102: Swift-BAT refined analysis
  87. GRB 090102: NOT redshift
  88. GRB 090102: Enhanced Swift-XRT position
  89. GRB 090102: REM observations of a bright afterglow
  90. GRB 090102: Swift detection of a burst with an optical counterpart
  91. GRB 090102: TAROT Calern observatory optical observations
  92. GRB 081230: GROND confirmation of the afterglow
  93. GRB081230: Swift-XRT refined analysis
  94. GRB 081230 Swift/UVOT Observations
  95. GRB 081230: Enhanced Swift-XRT position
  96. GRB 081230: Swift detection of a burst
  97. GRB 081228, Swift-BAT refined analysis
  98. VLA radio detection of GRB 081221
  99. GRB 081228: Swift/UVOT Upper Limits
  100. GRB 081228: Swift-XRT Team refined analysis

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov