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"

32508 results found.

  1. GRB 060926: MASTER OT alert observation
  2. GRB 060912A: Redshift of probable host galaxy
  3. GRB 060926: BOOTES-IR observations
  4. GRB060926 OPTIMA-Burst optical observation
  5. GRB 060926: MASTER optical observation
  6. GRB 060923C, Swift-BAT refined analysis
  7. GRB 060923C: VLA Observation
  8. GRB 060923C: NIR afterglow confirmed
  9. GRB060923C: AROMA optical obsevation
  10. GRB 060923C: Gemini Observations and Afterglow Candidate
  11. GRB 060923C, optical observation
  12. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  13. GRB 060923C: VLT J-band observations
  14. GRB060923B: Swift/UVOT upper limits
  15. GRB 060923B: Swift XRT Refined Analysis
  16. GRB 060923C: Swift XRT refined analysis
  17. GRB 060923C, Swift-BAT partial refined analysis
  18. GRB 060923A: Swift XRT refined analysis
  19. GRB 060923C: Keck Observations
  20. GRB 060923A: Keck and Gemini Observations
  21. GRB 060923B, Swift-BAT refined analysis
  22. GRB060923C : Faulkes Telescope South optical limits
  23. GRB060923C: Faulkes Telescope North optical observations
  24. GRB 060923C: optical observation
  25. GRB 060923, Swift-BAT refined analysis
  26. GRB 060923: Early Super-LOTIS Observations
  27. GRB 060923: UKIRT nIR observations - candidate afterglow
  28. GRB060923: Faulkes Telescope North optical observations
  29. GRB060923 - SDSS Pre-Burst Observations
  30. GRB 060923: KAIT observations
  31. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  32. GRB060919: Swift/UVOT optical observations
  33. GRB 060919 : Faulkes South Telescope Observations
  34. GRB 060919, Swift-BAT refined analysis
  35. GRB060919: XRT refined analysis
  36. GRB 060912A: VLA Observation
  37. GRB 060912A: Probable Host Galaxy
  38. GRB060825: MAGIC telescope GeV observation
  39. Konus-Wind observation of GRB 060912
  40. GRB 060912: Redshift of nearby 2MASS galaxy
  41. GRB060912: optical observations
  42. GRB060912: Swift/UVOT Observations
  43. GRB060912: OPTIMA-Burst optical observations
  44. GRB 060912: Swift XRT Team Refined Analysis
  45. GRB 060912, Swift-BAT refined analysis
  46. GRB 060912: Correction to GCN 5559
  47. VLA observations of GRB 060908
  48. GRB 060908: redshift
  49. GRB 060908, Swift/XRT refined analysis
  50. GRB 060908: Swift/UVOT Observations
  51. GRB 060908: Danish/DFOSC optical observations
  52. GRB 060908, Swift-BAT refined analysis
  53. GRB 060904B : CFHT/WIRCam NIR afterglow observations
  54. GRB 060908: REM optical prompt observation
  55. GRB 060904A: Suzaku/WAM observation of the prompt emission
  56. GRB060906 , optical observation
  57. GRB060904b optical detections (delayed report due to internet outage)
  58. GRB 060906: optical observation
  59. GRB 060906: Early RAPTOR optical limits
  60. GRB 060906, Swift-BAT refined spectral analysis
  61. GRB 060906: Swift/XRT Refined Analysis
  62. GRB 060906: Swift-UVOT observations
  63. VLT redshift of GRB 060906
  64. GRB 060906, Swift-BAT refined analysis
  65. GRB 060906: FRAM observations - flash determination (airplane)
  66. GRB 060906: KAIT observations
  67. GRB 060906: Confirmation of P60 Optical Afterglow
  68. GRB 060906: observations with FRAM
  69. GRB 060904A Milagro GeV/TeV Observations
  70. GRB060904b, optical observations
  71. GRB 060904b: SMARTS optical/IR afterglow observations
  72. GRB 060904B: RTT150 optical observations
  73. GRB060904A: Swift/UVOT optical observations
  74. GRB 060904A: Subaru NIR observation
  75. GRB 060904A: pseudo-z from spectral parameters of the prompt emission
  76. GRB 060904B: Swift-BAT refined analysis
  77. GRB060904b: Optical observations with Swift/UVOT
  78. Konus-Wind observation of GRB 060904A
  79. GRB 060904B: Swift-XRT refined analysis
  80. GRB 060904A: Refined analysis of the Swift-BAT burst
  81. GRB 060904A: Swift-XRT refined analysis
  82. GRB 060904A: Suzaku-XIS and -HXD observation plan
  83. GRB 060904B: VLT redshift
  84. GRB 060904A: P60 Observations
  85. GRB060904B: Watcher observations
  86. GRB 060904B BOOTES-IR and 1.5m OSN observations
  87. GRB 060904B: ROTSE-III Detection of Optical Counterpart
  88. 060901: Swift UVOT followup observations
  89. Konus-Wind observation of GRB 060901
  90. GRB 060901: SMARTS optical/IR observations update
  91. GRB 060901: Swift/XRT Refined Analysis
  92. GRB 060901: SMARTS optical/IR observations
  93. GRB 060901: Swift/XRT Position
  94. GRB 060901: Watcher observations
  95. GRB 060605, observations using an Integral Field Unit
  96. GRB 060604: VLA Observation
  97. GRB 060814: Suzaku/WAM observation of the prompt emission
  98. GRB 060605: VLA Observation
  99. GRB 060707: VLA observation
  100. GRB 060825: VLA observations

Advanced

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