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"

20384 results found.

  1. GRB050123,optical observation
  2. GRB 050123: KAIT observations
  3. CFHTLS optical transient unlikely to be a GRB
  4. GRB050117a: Radio Observations
  5. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  6. GRB050117: optical observation
  7. GRB050117: MASTER optical observations
  8. MASTER:GRB050117 SWIFT
  9. GRB050117: Swift-BAT detection of a long multi-peaked burst
  10. GRB050117: Swift XRT Position
  11. Triangulation of Short Hard GRB050112 (large error box)
  12. SGR 1806-20: Further low frequency GMRT results
  13. SGR1806-20: Swift-BAT observations of two additional bursts
  14. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  15. SGR 1806-20 and extragalactic short-duration GRBs
  16. Fourth Epoch VLA observations of SGR 1806-20
  17. SGR 1806-20, RHESSI observations of the 041227 giant flare
  18. Second-epoch VLA observations of SGR 1806-20
  19. SGR1806 VLA Observations
  20. GRB 041217: Optical observations
  21. GRB041219; RXTE ASM Observations
  22. GRB041226: Swift-BAT detection of a burst
  23. GRB041223: decay of the afterglow
  24. GRB 041224: near-infrared observations with REM
  25. GRB041223: optical and NIR observations with REM
  26. Swift-BAT Time History of GRB041219
  27. GRB 041219: TAROT optical observations
  28. GRB 041218: TAROT optical observations
  29. GRB 041223: J-band observations of the afterglow
  30. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  31. GRB 041219c: PROMPT Observations
  32. GRB041223: Swift-BAT detection of a bright long burst
  33. GRB 041218 Optical Observations
  34. GRB041219: Continued NIR Observations
  35. GRB 041219 ,optical observation
  36. GRB 041219: Radio Afterglow Detection
  37. GRB 041218 : Radio Observations
  38. GRB 041218: R-band optical observations
  39. GRB041218: optical observations
  40. GRB041219: Confirmed NIR Afterglow
  41. GRB041218: Continued P60 Optical Observations
  42. Swift-BAT detection of the bright long burst GRB041219
  43. GRB 041219: Infrared Afterglow Candidate
  44. GRB041219, BVRcIc field calibration
  45. GRB 041219: Infrared Afterglow Candidate
  46. GRB041218, BVRcIc field calibration
  47. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  48. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  49. GRB 041217: PROMPT Observations
  50. GRB 041218: Optical observations
  51. GRB 041217: LCO40 Optical Observations and Possible Candidates
  52. GRB041217: NIR and optical observations with REM
  53. GRB041217: Infrared Observations
  54. GRB041217: The First GRB Located On-Board Swift
  55. GRB041211: Faulkes Telescope continued optical monitoring
  56. Optical transient (GRB?) in Lynx
  57. GRB041211: RAPTOR observations
  58. GRB041211: Ashra Prototype optical observation
  59. GRB041211, BVRcIc field calibration
  60. GRB041211,optical observation
  61. GRB 041211: Infrared Observations
  62. GRB 041211: KAIT observations
  63. Triangulation of short GRB 041116 (large error box)
  64. GRB 040924: Afterglow Color
  65. GRB 041006: GETS Optical Afterglow Observation
  66. GRB 041006: Optical Observations
  67. GRB041006, late-time optical photometry
  68. GRB041006: RTT150 Optical Observations
  69. GRB 041016: BOOTES-2 simultaneous observation
  70. GRB041006: RTT150 Optical Observations
  71. GRB041016,optical observation
  72. GRB 041016: Optical limits
  73. GRB 041016:Optical limit during first minute
  74. GRB 041016: Optical limit
  75. GRB 041015 R band observations
  76. GRB040924, BVRcIc field calibration
  77. GRB041015,optical observation
  78. GRB041006: Fading X-ray Afterglow Observed with Chandra
  79. GRB041006: Optical observations and Potential host galaxy
  80. GRB041006, BVRcIc field calibration
  81. GRB 041006: SARA afterglow observations
  82. GRB041006, optical observation in CrAO
  83. Search for SN light in XRF 040912 with MEGACAM
  84. GRB 041006: BR observations with VATT
  85. GRB 041006: Redshift confirmed
  86. GRB041006, optical I observation
  87. ROTSE-IIIa Observations of GRB 041006
  88. GRB041006: MASTER optical observations
  89. GRB041006,optical observation
  90. GRB041006: Fading of optical afterglow candidate
  91. GRB 041006: Optical afterglow candidate
  92. radio observations, GRB 040924
  93. GRB040929,optical observation
  94. GRB040924,optical observation
  95. GRB040924,optical observation
  96. GRB040924: KAIT observations
  97. GRB 040924: Subaru NIR observation
  98. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  99. XRF040916: continuing decay of OT
  100. TAROT Observations of GRB 040916 (HETE #3558)

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