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"

16159 results found.

  1. Possible GRB 051221B: MDM Correction
  2. GRB050121: optical observation
  3. GRB050121b: optical observation
  4. GRB060124: optical observation
  5. GRB060124: optical observations
  6. GRB060124, BVRcIc field calibration
  7. GRB060124 optical observations
  8. GRB 060121: Probable Detection of NIR Afterglow
  9. GRB060124: optical observation
  10. GRB 060116 HST observations
  11. GRB 060124: HETE detection and spectrum of the main peak
  12. Refined XRT Position for GRB 060123
  13. GRB060124: detailed XRT analysis
  14. GRB 060124 Optical Observations
  15. GRB 060124: ART optical limits during the burst
  16. GRB060123: Optical and IR Imaging
  17. GRB 060124: Keck optical spectrum
  18. GRB 060124: MDM Optical Spectrum
  19. GRB 060124 : Optical observation at Xinglong and Kiso
  20. GRB060124: optical observations at Asiago
  21. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  22. GRB 060121: OHP optical limits
  23. GRB 060124: TAROT optical limits
  24. GRB 060124: Swift/UVOT Observation
  25. GRB 060124: Confirmation of the Afterglow
  26. GRB 060124: XRT position
  27. GRB 060124: Optical Afterglow Candidate from Tautenburg
  28. GRB060124, optical observation
  29. GRB 050124 : Kiso Optical limit
  30. GRB 060124: Optical Observations at Tautenburg
  31. GRB060124:MASTER optical observation
  32. GRB 060116: MARGE optical observations
  33. GRB 060121: Liverpool Telescopes optical limits
  34. GRB 060121: I-band Limits
  35. GRB 060121: Confirmation of Afterglow
  36. GRB 060121: candidate optical counterpart
  37. GRB 060121: optical observations
  38. GRB 060121: optical observations
  39. GRB 060121: Optical imaging
  40. GRB 060121 (=H4010): Results of preliminary spectral analysis
  41. GRB 060121: A bright short/hard GRB localized by HETE-2 SXC
  42. GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
  43. HETE Alert 4006: MASTER promt optical limit
  44. GRB060108: photometric redshift determination
  45. GRB 060117: FRAM refined analysis
  46. GRB 060117: FRAM optical afterglow candidate
  47. GRB 060116: VLT optical observations
  48. GRB060115: REM observations
  49. GRB 060116 : Lulin optical limit
  50. GRB 060116: ROTSE-III Optical Limits
  51. GRB 060115: absorption redshift
  52. GRB 060114: REM observations
  53. GRB 060115: Swift XRT refined analysis
  54. GRB 060115: OT finding chart
  55. GRB060115, optical observation
  56. GRB 060115: MITSuME optical afterglow candidate
  57. GRB060114, optical observation
  58. GRB 060108: IR observations of afterglow
  59. GRB 060108: Evidence for an XRT Position Offset
  60. GRB 060111B: Swift XRT refined analysis
  61. GRB 060111B: MITSuME detection of optical afterglow
  62. GRB 060111B: TAROT optical observation
  63. GRB060111A: RTT150 optical observations
  64. GRB060111B: RTT150, possible host galaxy
  65. GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
  66. GRB060111.2:_MASTER optical limit
  67. GRB 060111: TAROT optical observation
  68. GRB 060111: ROTSE-III Optical Limits
  69. GRB 060110: Mitsume optical observations
  70. GRB 060110a: RAPTOR detection of early optical emission.
  71. GRB 060110: ROTSE-III Confirmation of Optical Counterpart
  72. GRB060110, optical observation
  73. GRB 060110: Optical observation
  74. GRB 060110: Optical limit
  75. GRB060109, optical observation
  76. GRB060108: P200 Ks Observations
  77. GRB 060108: early UKIRT K-band observations
  78. GRB 060108: a dark burst?
  79. GRB 060108: Mitsume optical observations
  80. GRB060108: Faulkes Telescope observation
  81. GRB060108, optical observation
  82. GRB 060105: Mitsume optical observations
  83. GRB060105, optical observation
  84. GRB060105 : Kiso optical observation
  85. GRB051211B: optical observations
  86. GRB 051221B: Optical Observations with Kuiper 1.54m
  87. GRB 051227: optical observation
  88. GRB 051221A: VLA Radio Observations
  89. GRB051227: Radio Observations
  90. GRB 051227: optical afterglow
  91. GRB 051227: Joint Swift-HETE Spectral Analysis
  92. GRB 051227, optical observation
  93. GRB051117B: optical observation
  94. GRB 051221A: MDM Optical Observations
  95. GRB 051221A: Chandra Afterglow Position
  96. GRB 051221B: ROTSE-III Optical Limits
  97. GRB 051221B: TAROT optical limits
  98. GRB 051221A: WSRT Radio Observations
  99. GRB 051221: Continued fading of optical afterglow
  100. Possible GRB 051221B: MDM Optical Detection

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