Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

32711 results found.

  1. GRB050126: MASTER optical observations
  2. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  3. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  4. GRB050124: No Swift UVOT Detection of Afterglow Emission
  5. GRB 050124, SMARTS optical/IR observations
  6. GRB 050117a: Radio Observations
  7. GRB 050124 I-band observation
  8. GRB 050124: NIR Candidates from Keck/NIRC
  9. GRB050124,optical observation
  10. GRB 050124 : Lulin R-band follow-up observation
  11. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  12. GRB050124: Refined BAT position, spectral and fluence information
  13. GRB 050123 : I-band follow-up observation
  14. GRB050123: optical limit 1.8h before GRB
  15. GRB 050123: KAIT observations
  16. GRB050123: P60 Observations
  17. CFHTLS optical transient unlikely to be a GRB
  18. GRB050117a: Radio Observations
  19. GRB050117a: Refined analysis
  20. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  21. GRB050117: Palomar WIRC Ks-band observations
  22. GRB050117: optical observation
  23. GRB 050117, I-band observations
  24. GRB 050117: Optical observation
  25. GRB050117: Refined XRT position
  26. GRB050117: MASTER optical observations
  27. MASTER:GRB050117 SWIFT
  28. GRB050117: Swift-BAT detection of a long multi-peaked burst
  29. SGR 1806-20: RXTE/PCA pulse frequency during flare
  30. SGR 1806-20: Further low frequency GMRT results
  31. SGR1806-20: Swift-BAT observations of two additional bursts
  32. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  33. Further VLA observations of SGR 1806-20
  34. SGR 1806-20 and extragalactic short-duration GRBs
  35. Fourth Epoch VLA observations of SGR 1806-20
  36. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  37. SGR 1806-20: Temporal and Spectral behavior of radio transient
  38. ATCA observations of SGR 1806-20
  39. SGR 1806-20, RHESSI observations of the 041227 giant flare
  40. Third epoch observations of SGR 1806-20 with VLA
  41. Second Epoch VLA observations of SGR 1806-20
  42. Second-epoch VLA observations of SGR 1806-20
  43. SGR1806: Detection of a Sudden Ionospheric Disturbance
  44. DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
  45. VLA observations of SGR 1806-20
  46. SGR1806 VLA Observations
  47. VLA observations of SGR 1806-20
  48. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  49. GRB 041217: Optical observations
  50. GRB041219, early time observations
  51. The giant outburst from SGR 1806-20
  52. IPN localization of giant flare from SGR1806-20
  53. GRB041228: ROTSE-III Optical Observations
  54. GRB041219; RXTE ASM Observations
  55. NIR Observations of GRB 041219
  56. GRB041226: ROTSE-III Optical Observations
  57. GRB041223: decay of the afterglow
  58. GRB041224: ROTSE-III Optical Observations
  59. GRB 041224: near-infrared observations with REM
  60. GRB 041223: XRT afterglow spectrum and light curve
  61. GRB 041223 Fluence measured by Swift-BAT
  62. GRB041223: optical and NIR observations with REM
  63. Swift-BAT Time History of GRB041219
  64. GRB 041219: TAROT optical observations
  65. GRB 041223: J-band observations of the afterglow
  66. GRB 041223: Detection of Optical Transient with LCO40
  67. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  68. GRB 041219c: PROMPT Observations
  69. GRB041223: ROTSE-III Optical Observations
  70. GRB 041218: optical observations
  71. Very high activity of SGR 1806-20
  72. GRB 041219: Second Epoch WSRT Radio Observations
  73. GRB 041219: WSRT Radio Afterglow Detection
  74. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  75. GRB 041218: Optical observations
  76. GRB 041219 : optical follow-up observations
  77. Deep RAPTOR observations during GRB 041219
  78. GRB 041218 Optical Observations
  79. GRB 041219 Optical Observations
  80. GRB041219: Optical Afterglow Detection
  81. GRB041219: Continued NIR Observations
  82. GRB 041219: Radio Afterglow Detection
  83. GRB 041218 : Radio Observations
  84. GRB 041218: R-band optical observations
  85. GRB041218: Liverpool Telescope optical observations
  86. GRB041218: optical observations
  87. GRB041219: Confirmed NIR Afterglow
  88. Swift-BAT detection of the bright long burst GRB041219
  89. GRB 041218: Optical Observation
  90. GRB 041219: Infrared Afterglow Candidate
  91. GRB041219, BVRcIc field calibration
  92. GRB 041219: Infrared Afterglow Candidate
  93. GRB041218, BVRcIc field calibration
  94. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  95. GRB 041217: PROMPT Observations
  96. GRB041218: optical observations
  97. GRB041217: optical limit 30 min after GRB
  98. GRB 041218; optical candidate
  99. GRB 041218: Optical observations
  100. GRB 041217: LCO40 Optical Observations and Possible Candidates

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