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"

36146 results found.

  1. GRB 050306: REM optical-infrared observations
  2. GRB 050306: Possible X-ray Afterglow Position from the Swift
  3. Swift trigger 107518: optical observation
  4. GRB 050306: TAROT optical observations
  5. GRB 050306,optical observation
  6. GRB 050306: Swift-BAT detection of a long burst
  7. GRB 050126: Confirmation of the NIR afterglow candidate
  8. PROMPT VRcIc Observations of GRB 050223
  9. XRF/GRB 050215B: Radio Observations
  10. XMM-Newton Images of GRB 050223
  11. GRB 050219b: candidate NIR afterglow
  12. IBAS GRB Alert #2321
  13. GRB 050223: optical observations
  14. INTEGRAL detection of GRB 050223
  15. GRB 050223 : Planned XMM-Newton observation
  16. GRB050223: ROTSE-III Optical Observations
  17. GRB 050223 Swift/BAT detection of a burst
  18. GRB 050223: Swift XRT Position
  19. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  20. GRB 050219b: CORRECTION to refined XRT position
  21. GRB 050219a: Optical observations from LCO
  22. GRB 050219b: Optical and near-IR observations from LCO
  23. GRB 050219b: Refined XRT position
  24. GRB 050219b: Swift-BAT detection of a burst
  25. GRB 050219b: CORRECTION: Swift XRT Position
  26. GRB 050219b: Swift XRT Position
  27. GRB 050219a, optical observations
  28. GRB 050219a: Refined XRT position
  29. GRB 050219: Swift-BAT detection of a burst
  30. GRB050215b: Swift UVOT Detection of Afterglow Emission
  31. GRB 050219: Prompt X-ray position
  32. GRB 050215B: Radio Observations
  33. GRB 050215b: XRT confirmation of IR afterglow candidate
  34. GRB050215b: P60 Optical Observations
  35. GRB 050215b: Swift XRT Source Variability
  36. GRB 050215B: candidate afterglow
  37. GRB 050215b : Lulin follow-up observation
  38. GRB 050215b, BOOTES-2 simultaneous optical observations
  39. GRB 050215B: UKIRT K-band imaging
  40. GRB 050215b: Swift XRT Observations
  41. GRB 050215b, BOOTES-1B optical limit
  42. GRB050215A: ROTSE-III Optical Observations
  43. GRB050209: TAROT optical observations
  44. GRB 050209(=U11568): Duration and spectrum
  45. short/hard GRB 050202, optical observations
  46. GRB050209: REM optical observations
  47. GRB 050209 I-band observation
  48. GRB 050209 Optical observations
  49. GRB050209: P60 Optical Observations
  50. GRB050209 (=U11568): A Long GRB Detected by HETE
  51. GRB 050209: Optical observation
  52. GRB 050128: Radio observations
  53. Further analysis of the short Swift-BAT GRB 050202
  54. GRB 050202: Second epoch radio observations
  55. GRB 050129: Optical observations
  56. GRB050202: Radio Observations
  57. GRB 050202: Optical observations with LCO40
  58. GRB 050202: Short burst detected by Swift-BAT
  59. GRB 050128 Optical observation with REM
  60. GRB 050129: a weak long GRB detected with INTEGRAL
  61. GRB050128: Faulkes Telescope South observations
  62. GRB 050124: Radio Observations
  63. GRB 050128: near-infrared observations with REM
  64. GRB050128,optical observations
  65. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  66. GRB 050126: Radio Observations
  67. GRB050128 Swift-BAT observations
  68. GRB 050128: Swift XRT prompt afterglow position
  69. GRB 050124: K-band afterglow observations
  70. GRB050126: MASTER optical limit for KECK OT
  71. GRB050126: MASTER optical observations
  72. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  73. GRB 050126: Prompt XRT detection and localization
  74. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  75. GRB 050124, SMARTS optical/IR observations
  76. GRB 050117a: Radio Observations
  77. GRB 050124 I-band observation
  78. GRB 050124: NIR Candidates from Keck/NIRC
  79. GRB050124,optical observation
  80. GRB 050124 : Lulin R-band follow-up observation
  81. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  82. GRB 050123 : I-band follow-up observation
  83. GRB050123: optical limit 1.8h before GRB
  84. GRB050123,optical observation
  85. GRB 050123: KAIT observations
  86. GRB050123: P60 Observations
  87. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  88. CFHTLS optical transient unlikely to be a GRB
  89. Unusual optical transient (GRB ???)
  90. GRB050117a: Radio Observations
  91. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  92. GRB 050117, I-band observations
  93. GRB 050117: Optical observation
  94. GRB050117: Refined XRT position
  95. GRB050117: MASTER optical observations
  96. MASTER:GRB050117 SWIFT
  97. GRB050117: Swift-BAT detection of a long multi-peaked burst
  98. Triangulation of Short Hard GRB050112 (large error box)
  99. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  100. SGR 1806-20 and extragalactic short-duration GRBs

Advanced

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