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"

37677 results found.

  1. GRB050128,optical observations
  2. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  3. GRB 050126: Radio Observations
  4. GRB050128 Swift-BAT observations
  5. GRB 050128: Swift XRT prompt afterglow position
  6. GRB 050124: K-band afterglow observations
  7. GRB050126: MASTER optical limit for KECK OT
  8. GRB050126: MASTER optical observations
  9. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  10. GRB 050126: Prompt XRT detection and localization
  11. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  12. GRB 050124, SMARTS optical/IR observations
  13. GRB 050117a: Radio Observations
  14. GRB 050124 I-band observation
  15. GRB 050124: NIR Candidates from Keck/NIRC
  16. GRB050124,optical observation
  17. GRB 050124 : Lulin R-band follow-up observation
  18. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  19. GRB 050123 : I-band follow-up observation
  20. GRB050123: optical limit 1.8h before GRB
  21. GRB050123,optical observation
  22. GRB 050123: KAIT observations
  23. GRB050123: P60 Observations
  24. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  25. CFHTLS optical transient unlikely to be a GRB
  26. Unusual optical transient (GRB ???)
  27. GRB050117a: Radio Observations
  28. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  29. GRB 050117, I-band observations
  30. GRB 050117: Optical observation
  31. GRB050117: Refined XRT position
  32. GRB050117: MASTER optical observations
  33. MASTER:GRB050117 SWIFT
  34. GRB050117: Swift-BAT detection of a long multi-peaked burst
  35. Triangulation of Short Hard GRB050112 (large error box)
  36. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  37. SGR 1806-20 and extragalactic short-duration GRBs
  38. SGR 1806-20: Temporal and Spectral behavior of radio transient
  39. SGR 1806-20, RHESSI observations of the 041227 giant flare
  40. SGR1806: Detection of a Sudden Ionospheric Disturbance
  41. GRB 041217: Optical observations
  42. GRB041219, early time observations
  43. IPN localization of giant flare from SGR1806-20
  44. GRB041219; RXTE ASM Observations
  45. NIR Observations of GRB 041219
  46. GRB041223: decay of the afterglow
  47. GRB 041224: near-infrared observations with REM
  48. GRB 041223: XRT afterglow spectrum and light curve
  49. GRB 041223 Fluence measured by Swift-BAT
  50. GRB041223: optical and NIR observations with REM
  51. GRB 041219: TAROT optical observations
  52. GRB 041218: TAROT optical observations
  53. GRB 041223: J-band observations of the afterglow
  54. GRB 041223: Detection of Optical Transient with LCO40
  55. GRB 041219c: PROMPT Observations
  56. GRB 041218: optical observations
  57. GRB 041219: Second Epoch WSRT Radio Observations
  58. GRB 041219: WSRT Radio Afterglow Detection
  59. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  60. GRB 041218: Optical observations
  61. GRB 041219 : optical follow-up observations
  62. Deep RAPTOR observations during GRB 041219
  63. GRB 041218 Optical Observations
  64. GRB 041219 Optical Observations
  65. GRB041219c: Third Burst in One Day from Swift-BAT
  66. GRB041219: Optical Afterglow Detection
  67. GRB041219: Continued NIR Observations
  68. GRB 041219 ,optical observation
  69. GRB 041219: Radio Afterglow Detection
  70. GRB 041218 : Radio Observations
  71. GRB 041218: R-band optical observations
  72. GRB041219: Confirmed NIR Afterglow
  73. GRB041218: Continued P60 Optical Observations
  74. GRB 041218: Optical Observation
  75. GRB 041219: Infrared Afterglow Candidate
  76. GRB041219, BVRcIc field calibration
  77. GRB 041219: Infrared Afterglow Candidate
  78. GRB041218, BVRcIc field calibration
  79. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  80. GRB041219: P60 Optical Observations
  81. GRB 041219 - A long GRB detected by INTEGRAL
  82. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  83. GRB 041217: PROMPT Observations
  84. GRB041218: optical observations
  85. GRB041217: optical limit 30 min after GRB
  86. GRB 041218; optical candidate
  87. GRB 041218: Optical observations
  88. GRB 041217: LCO40 Optical Observations and Possible Candidates
  89. GRB 041218 - A long GRB detected by integral
  90. GRB041217: Optical Observations
  91. GRB041217: P60 Optical Observations
  92. GRB041217: Infrared Observations
  93. GRB041217: The First GRB Located On-Board Swift
  94. GRB041211: Faulkes Telescope continued optical monitoring
  95. Optical Transient in Lynx not a GRB
  96. Optical transient (GRB?) in Lynx
  97. Optical transient (GRB?) in Lynx, UT Dec 11.4436
  98. GRB041211: Continued P60 Observations
  99. GRB041211: RAPTOR observations
  100. GRB041211: Ashra Prototype optical observation

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