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"

36036 results found.

  1. GRB 050306,optical observation
  2. GRB 050306: Swift-BAT detection of a long burst
  3. GRB 050126: Confirmation of the NIR afterglow candidate
  4. PROMPT VRcIc Observations of GRB 050223
  5. XRF/GRB 050215B: Radio Observations
  6. XMM-Newton Images of GRB 050223
  7. GRB 050219b: candidate NIR afterglow
  8. IBAS GRB Alert #2321
  9. GRB 050223: optical observations
  10. INTEGRAL detection of GRB 050223
  11. GRB 050223 : Planned XMM-Newton observation
  12. GRB050223: ROTSE-III Optical Observations
  13. GRB 050223 Swift/BAT detection of a burst
  14. GRB 050223: Swift XRT Position
  15. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  16. GRB 050219b: CORRECTION to refined XRT position
  17. GRB 050219a: Optical observations from LCO
  18. GRB 050219b: Optical and near-IR observations from LCO
  19. GRB 050219b: Refined XRT position
  20. GRB 050219b: Swift-BAT detection of a burst
  21. GRB 050219b: CORRECTION: Swift XRT Position
  22. GRB 050219b: Swift XRT Position
  23. GRB 050219a, optical observations
  24. GRB 050219a: Refined XRT position
  25. GRB 050219: Swift-BAT detection of a burst
  26. GRB050215b: Swift UVOT Detection of Afterglow Emission
  27. GRB 050219: Prompt X-ray position
  28. GRB 050215B: Radio Observations
  29. GRB 050215b: XRT confirmation of IR afterglow candidate
  30. GRB050215b: P60 Optical Observations
  31. GRB 050215b: Swift XRT Source Variability
  32. GRB 050215B: candidate afterglow
  33. GRB 050215b : Lulin follow-up observation
  34. GRB 050215b, BOOTES-2 simultaneous optical observations
  35. GRB 050215B: UKIRT K-band imaging
  36. GRB 050215b: Swift XRT Observations
  37. GRB 050215b, BOOTES-1B optical limit
  38. GRB050215A: ROTSE-III Optical Observations
  39. GRB050209: TAROT optical observations
  40. GRB 050209(=U11568): Duration and spectrum
  41. short/hard GRB 050202, optical observations
  42. GRB050209: REM optical observations
  43. GRB 050209 I-band observation
  44. GRB 050209 Optical observations
  45. GRB050209: P60 Optical Observations
  46. GRB050209 (=U11568): A Long GRB Detected by HETE
  47. GRB 050209: Optical observation
  48. GRB 050128: Radio observations
  49. Further analysis of the short Swift-BAT GRB 050202
  50. GRB 050202: Second epoch radio observations
  51. GRB 050129: Optical observations
  52. GRB050202: Radio Observations
  53. GRB 050202: Optical observations with LCO40
  54. GRB 050202: Short burst detected by Swift-BAT
  55. GRB 050128 Optical observation with REM
  56. GRB 050129: a weak long GRB detected with INTEGRAL
  57. GRB050128: Faulkes Telescope South observations
  58. GRB 050124: Radio Observations
  59. GRB 050128: near-infrared observations with REM
  60. GRB050128,optical observations
  61. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  62. GRB 050126: Radio Observations
  63. GRB050128 Swift-BAT observations
  64. GRB 050128: Swift XRT prompt afterglow position
  65. GRB 050124: K-band afterglow observations
  66. GRB050126: MASTER optical limit for KECK OT
  67. GRB050126: MASTER optical observations
  68. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  69. GRB 050126: Prompt XRT detection and localization
  70. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  71. GRB 050124, SMARTS optical/IR observations
  72. GRB 050117a: Radio Observations
  73. GRB 050124 I-band observation
  74. GRB 050124: NIR Candidates from Keck/NIRC
  75. GRB050124,optical observation
  76. GRB 050124 : Lulin R-band follow-up observation
  77. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  78. GRB 050123 : I-band follow-up observation
  79. GRB050123: optical limit 1.8h before GRB
  80. GRB050123,optical observation
  81. GRB 050123: KAIT observations
  82. GRB050123: P60 Observations
  83. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  84. CFHTLS optical transient unlikely to be a GRB
  85. Unusual optical transient (GRB ???)
  86. GRB050117a: Radio Observations
  87. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  88. GRB 050117, I-band observations
  89. GRB 050117: Optical observation
  90. GRB050117: Refined XRT position
  91. GRB050117: MASTER optical observations
  92. MASTER:GRB050117 SWIFT
  93. GRB050117: Swift-BAT detection of a long multi-peaked burst
  94. Triangulation of Short Hard GRB050112 (large error box)
  95. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  96. SGR 1806-20 and extragalactic short-duration GRBs
  97. SGR 1806-20: Temporal and Spectral behavior of radio transient
  98. SGR 1806-20, RHESSI observations of the 041227 giant flare
  99. SGR1806: Detection of a Sudden Ionospheric Disturbance
  100. GRB 041217: Optical 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