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"

36154 results found.

  1. GRB 050306: further TAROT optical data
  2. GRB050309: Early optical limit from P60
  3. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  4. GRB 050309 : Lulin R-band observation
  5. Swift 107873: P60 Optical Observations
  6. GRB 050306: CORRECTION to date of observation
  7. GRB 050306: R-band observations
  8. GRB 050306: No Swift UVOT Optical Counterpart Detected
  9. GRB 050306: REM optical-infrared observations
  10. GRB 050306: Possible X-ray Afterglow Position from the Swift
  11. Swift trigger 107518: optical observation
  12. GRB 050306: TAROT optical observations
  13. GRB 050306,optical observation
  14. GRB 050306: Swift-BAT detection of a long burst
  15. GRB 050126: Confirmation of the NIR afterglow candidate
  16. PROMPT VRcIc Observations of GRB 050223
  17. XRF/GRB 050215B: Radio Observations
  18. XMM-Newton Images of GRB 050223
  19. GRB 050219b: candidate NIR afterglow
  20. IBAS GRB Alert #2321
  21. GRB 050223: optical observations
  22. INTEGRAL detection of GRB 050223
  23. GRB 050223 : Planned XMM-Newton observation
  24. GRB050223: ROTSE-III Optical Observations
  25. GRB 050223 Swift/BAT detection of a burst
  26. GRB 050223: Swift XRT Position
  27. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  28. GRB 050219b: CORRECTION to refined XRT position
  29. GRB 050219a: Optical observations from LCO
  30. GRB 050219b: Optical and near-IR observations from LCO
  31. GRB 050219b: Refined XRT position
  32. GRB 050219b: Swift-BAT detection of a burst
  33. GRB 050219b: CORRECTION: Swift XRT Position
  34. GRB 050219b: Swift XRT Position
  35. GRB 050219a, optical observations
  36. GRB 050219a: Refined XRT position
  37. GRB 050219: Swift-BAT detection of a burst
  38. GRB050215b: Swift UVOT Detection of Afterglow Emission
  39. GRB 050219: Prompt X-ray position
  40. GRB 050215B: Radio Observations
  41. GRB 050215b: XRT confirmation of IR afterglow candidate
  42. GRB050215b: P60 Optical Observations
  43. GRB 050215b: Swift XRT Source Variability
  44. GRB 050215B: candidate afterglow
  45. GRB 050215b : Lulin follow-up observation
  46. GRB 050215b, BOOTES-2 simultaneous optical observations
  47. GRB 050215B: UKIRT K-band imaging
  48. GRB 050215b: Swift XRT Observations
  49. GRB 050215b, BOOTES-1B optical limit
  50. GRB050215A: ROTSE-III Optical Observations
  51. GRB050209: TAROT optical observations
  52. GRB 050209(=U11568): Duration and spectrum
  53. short/hard GRB 050202, optical observations
  54. GRB050209: REM optical observations
  55. GRB 050209 I-band observation
  56. GRB 050209 Optical observations
  57. GRB050209: P60 Optical Observations
  58. GRB050209 (=U11568): A Long GRB Detected by HETE
  59. GRB 050209: Optical observation
  60. GRB 050128: Radio observations
  61. Further analysis of the short Swift-BAT GRB 050202
  62. GRB 050202: Second epoch radio observations
  63. GRB 050129: Optical observations
  64. GRB050202: Radio Observations
  65. GRB 050202: Optical observations with LCO40
  66. GRB 050202: Short burst detected by Swift-BAT
  67. GRB 050128 Optical observation with REM
  68. GRB 050129: a weak long GRB detected with INTEGRAL
  69. GRB050128: Faulkes Telescope South observations
  70. GRB 050124: Radio Observations
  71. GRB 050128: near-infrared observations with REM
  72. GRB050128,optical observations
  73. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  74. GRB 050126: Radio Observations
  75. GRB050128 Swift-BAT observations
  76. GRB 050128: Swift XRT prompt afterglow position
  77. GRB 050124: K-band afterglow observations
  78. GRB050126: MASTER optical limit for KECK OT
  79. GRB050126: MASTER optical observations
  80. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  81. GRB 050126: Prompt XRT detection and localization
  82. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  83. GRB 050124, SMARTS optical/IR observations
  84. GRB 050117a: Radio Observations
  85. GRB 050124 I-band observation
  86. GRB 050124: NIR Candidates from Keck/NIRC
  87. GRB050124,optical observation
  88. GRB 050124 : Lulin R-band follow-up observation
  89. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  90. GRB 050123 : I-band follow-up observation
  91. GRB050123: optical limit 1.8h before GRB
  92. GRB050123,optical observation
  93. GRB 050123: KAIT observations
  94. GRB050123: P60 Observations
  95. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  96. CFHTLS optical transient unlikely to be a GRB
  97. Unusual optical transient (GRB ???)
  98. GRB050117a: Radio Observations
  99. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  100. GRB 050117, I-band 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