Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

6522 results found.

  1. GRB050820B: analysis of the XMM-Newton observation
  2. GRB 050916: Swift-BAT refined analysis
  3. Swift-BAT trigger 155764 is not a GRB
  4. GRB050916 : Swift-XRT refined analysis
  5. GRB 050915B: Swift-BAT refined analysis
  6. GRB 050915: Swift-BAT refined analysis
  7. GRB050911: Upper limit on X-ray afterglow
  8. Swift-BAT trigger 155072 ground analysis
  9. GRB 050908: Swift-BAT refined analysis
  10. GRB 050908: Optical observations
  11. GRB 050906: Swift XRT upper limit
  12. GRB 050904: Keck I-band Imaging
  13. GRB 050904: early Swift XRT analysis results
  14. GRB050904: Optical Observations
  15. GRB 050827: Swift XRT preliminary analysis results
  16. GRB 050827: P200 NIR Observations
  17. GRB 050827: Swift-BAT refined analysis
  18. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  19. GRB050822: Swift/UVOT upper limits
  20. GRB 050730, optical observation
  21. GRB050805b: CrAO optical limit
  22. GRB050805a : Null detection report
  23. GRB 050805b: OHP optical limits
  24. GRB 050730: OHP optical observations
  25. GRB 050802 : Lulin Optical follow-up observation
  26. GRB 050730: XRT refined analysis
  27. Swift/UVOT photometry of GRB050730
  28. GRB 050730, optical candidate
  29. GRB 050724: Chandra Observations of the X-ray Afterglow
  30. GRB050713: analysis of the XMM-Newton observation
  31. GRB 050724 : Lulin early R-band monitoring observations
  32. GRB 050714a: Refined XRT analysis and afterglow confirmation
  33. GRB 050714B: refined XRT analysis
  34. GRB 050713A: XRT refined analysis
  35. GRB050712: TNG R-band observations
  36. GRB 050713b : Lulin R-band observations
  37. GRB 050713: ARC NIR Detections and Identification of Fading
  38. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  39. GRB 050626: Swift XRT observations
  40. GRB 050408: ARC 3.5-meter NIR Observations
  41. GRB 050603 - XRT data analysis of the first day
  42. GRB 050603: INTEGRAL shows it is not a short GRB
  43. GRB 050525a, infrared observations
  44. GRB 050509b: refined XRT/Chandra afterglow position analysis
  45. GRB 050525a: SARA Observations
  46. XRF050522: NIR observations of XRT candidate
  47. XRF 050522: Continued NIR P200 Monitoring
  48. XRF050522: Near-infrared Observations
  49. XRF050509C: Chandra Afterglow Detection
  50. XRF 050509c: Swift XRT Upper Limit
  51. GRB 050520: P200 Observations
  52. GRB 050520: OSN optical observations
  53. GRB 050504: Swift XRT afterglow candidate has faded
  54. Refined Chandra analysis of GRB 050509b
  55. Chandra observation of GRB 050509b
  56. GRB 050509b Milagro GeV/TeV Observations
  57. GRB 050509b: No Optical Variability in XRT Error Circle
  58. GRB 050509b: Possible Optical Counterpart
  59. GRB 050502a: Swift XRT Upper Limit
  60. GRB050505: Optical Afterglow Candidate
  61. GRB 050504, R band Observations
  62. GRB (?) 050504: IR Observations, Intriguing Source
  63. GRB050502A: Optical Observations
  64. GRB 050502: Confirmed variability of the afterglow candidate +
  65. GRB 050421: Further Analysis of IR imaging
  66. GRB 050421: IR Observations
  67. GRB050326: analysis of the XMM-Newton observation
  68. GRB050416B: IR observations
  69. GRB050416: P200 NIR Observations
  70. GRB 050412 : XingLong optical observation
  71. GRB050410 : Null detection report
  72. GRB 050408: Swift XRT measurement of possible jet break
  73. GRB 050408: SOAR UBVRc Observations
  74. GRB 050408: Swift XRT analysis
  75. GRB050408: REM NIR and Optical observation
  76. GRB 050406: early Swift XRT analysis results
  77. GRB 050402: Early observations with Swift-UVOT
  78. GRB 050326 XMM-Newton observation
  79. GRB050223: analysis of the XMM-Newton observation
  80. Swift-BAT trigger 107873: No Swift XRT counterpart
  81. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  82. GRB 050309 : Lulin R-band observation
  83. GRB 050306: REM optical-infrared observations
  84. GRB 050126: Confirmation of the NIR afterglow candidate
  85. GRB 050219b: candidate NIR afterglow
  86. GRB 050219b: Optical and near-IR observations from LCO
  87. GRB 050215b : Lulin follow-up observation
  88. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  89. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  90. GRB 050124: NIR Candidates from Keck/NIRC
  91. GRB050117: Palomar WIRC Ks-band observations
  92. GRB050117: optical observation
  93. GRB 050117, I-band observations
  94. GRB 041217: Optical observations
  95. Giant flare from SGR 1806-20 detected by INTEGRAL
  96. NIR Observations of GRB 041219
  97. GRB041226: ROTSE-III Optical Observations
  98. Swift-BAT Time History of GRB041219
  99. GRB 041219 : optical follow-up observations
  100. Swift-BAT detection of the bright long burst GRB041219

Advanced

Download all Circulars as a .tar.gz archive:
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