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"

6791 results found.

  1. GRB 050714a: Refined XRT analysis and afterglow confirmation
  2. GRB 050714B: refined XRT analysis
  3. GRB 050713A: XRT refined analysis
  4. GRB050712: TNG R-band observations
  5. GRB 050713b : Lulin R-band observations
  6. GRB 050713: ARC NIR Detections and Identification of Fading
  7. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  8. GRB 050626: Swift XRT observations
  9. GRB 050408: ARC 3.5-meter NIR Observations
  10. GRB 050603 - XRT data analysis of the first day
  11. GRB 050603: INTEGRAL shows it is not a short GRB
  12. GRB 050525a, infrared observations
  13. GRB 050509b: refined XRT/Chandra afterglow position analysis
  14. GRB 050525a: SARA Observations
  15. XRF050522: NIR observations of XRT candidate
  16. XRF 050522: Continued NIR P200 Monitoring
  17. XRF050522: Near-infrared Observations
  18. XRF050509C: Chandra Afterglow Detection
  19. XRF 050509c: Swift XRT Upper Limit
  20. GRB 050520: P200 Observations
  21. GRB 050520: OSN optical observations
  22. GRB 050504: Swift XRT afterglow candidate has faded
  23. Refined Chandra analysis of GRB 050509b
  24. Chandra observation of GRB 050509b
  25. GRB 050509b Milagro GeV/TeV Observations
  26. GRB 050509b: No Optical Variability in XRT Error Circle
  27. GRB 050509b: Possible Optical Counterpart
  28. GRB 050502a: Swift XRT Upper Limit
  29. GRB050505: Optical Afterglow Candidate
  30. GRB 050504, R band Observations
  31. GRB (?) 050504: IR Observations, Intriguing Source
  32. GRB050502A: Optical Observations
  33. GRB 050502: Confirmed variability of the afterglow candidate +
  34. GRB 050421: Further Analysis of IR imaging
  35. GRB 050421: IR Observations
  36. GRB050326: analysis of the XMM-Newton observation
  37. GRB050416B: IR observations
  38. GRB050416: P200 NIR Observations
  39. GRB 050412 : XingLong optical observation
  40. GRB050410 : Null detection report
  41. GRB 050408: Swift XRT measurement of possible jet break
  42. GRB 050408: SOAR UBVRc Observations
  43. GRB 050408: Swift XRT analysis
  44. GRB050408: REM NIR and Optical observation
  45. GRB 050406: early Swift XRT analysis results
  46. GRB 050402: Early observations with Swift-UVOT
  47. GRB 050326 XMM-Newton observation
  48. GRB050223: analysis of the XMM-Newton observation
  49. Swift-BAT trigger 107873: No Swift XRT counterpart
  50. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  51. GRB 050309 : Lulin R-band observation
  52. GRB 050306: REM optical-infrared observations
  53. GRB 050126: Confirmation of the NIR afterglow candidate
  54. GRB 050219b: candidate NIR afterglow
  55. GRB 050219b: Optical and near-IR observations from LCO
  56. GRB 050215b : Lulin follow-up observation
  57. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  58. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  59. GRB 050124: NIR Candidates from Keck/NIRC
  60. GRB050117: Palomar WIRC Ks-band observations
  61. GRB050117: optical observation
  62. GRB 050117, I-band observations
  63. GRB 041217: Optical observations
  64. Giant flare from SGR 1806-20 detected by INTEGRAL
  65. NIR Observations of GRB 041219
  66. GRB041226: ROTSE-III Optical Observations
  67. Swift-BAT Time History of GRB041219
  68. GRB 041219 : optical follow-up observations
  69. Swift-BAT detection of the bright long burst GRB041219
  70. GRB 041211: Infrared Observations
  71. GRB 041211: Optical follow-up in East Asian region
  72. GRB041015: Near-Infrared observations
  73. GRB 040924: Afterglow Color
  74. GRB 041006: Optical Observations
  75. GRB041006: RTT150 Optical Observations
  76. GRB041015 : Multi epoch optical observations
  77. GRB 041016: Optical limits
  78. GRB 041016:Optical limit during first minute
  79. GRB 041015: Optical Observations at Rikubetsu
  80. GRB041006: Near Infrared observations
  81. GRB 041016: Optical limit
  82. GRB041015 : Optical follow-up at Kiso
  83. GRB041006, optical observation
  84. GRB 041006: Optical afterglow candidate
  85. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  86. GRB040924: KAIT observations
  87. GRB 040924, optical follow-up
  88. XRF 040912, identification of CXO sources
  89. XRF 040916, optical follow-up
  90. GRB 040912: Optical Observations
  91. Optical observations of GRB/XRF 040912 = HETE 3557
  92. GRB040912 : Kiso Optical follow-up observation
  93. HETE 3557: Optical observations
  94. GRB040827: analysis of the XMM-Newton observation
  95. GRB 040827: 2nd epoch of Magellan K-band imaging
  96. GRB 040827: Detection of NIR afterglow
  97. GRB 040825: Optical observations
  98. GRB 040812: Second epoch CXO Observations
  99. CXO observation of GRB 040812
  100. GRB 040730, infrared 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