Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

4876 results found.

  1. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  2. Swift detection of an RS CVn flare star
  3. GRB 051117B: ROTSE-III Optical Limits
  4. GRB 051109A
  5. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  6. GRB051109A: XRT refined analysis
  7. GRB 051105b: ART optical limits
  8. GRB051028: Swift/UVOT upper limits
  9. GRB051021a: optical observations
  10. GRB051021b: Magellan IR Imaging
  11. GRB 051021: P200 Ks Observations
  12. GRB051021B: Swift XRT Position
  13. GRB 051016B: Swift detection of a soft burst
  14. GRB050805A: Rc optical observations
  15. GRB 051001: Swift XRT refined analysis
  16. GRB 050922C: further VLT observations
  17. GRB 050925: WSRT Radio Observations
  18. GRB050922B: refined XRT analysis
  19. GRB050922C: Optical Observations
  20. GRB050918: Possible Swift/XRT detected afterglow
  21. GRB 050916: Swift-BAT refined analysis
  22. GRB 050915b, SMARTS optical/IR observations of the XRT position
  23. GRB 050915B: Swift-BAT refined analysis
  24. GRB 050915B: XRT position
  25. GRB050915B: Swift-BAT detection of a long bright burst
  26. GRB 050915: Swift XRT refined analysis
  27. GRB 050915: ROTSE-III optical limits
  28. GRB 050915: Swift detection of a GRB
  29. GRB050908 : Swift-XRT refined analysis
  30. GRB 050908: KAIT observations
  31. GRB 050906: Swift/BAT Detection of a possible burst
  32. GRB 050824: MDM Observations
  33. GRB 050826: Swift XRT preliminary analysis results
  34. GRB050824: First 2 hours of power low optical decay?
  35. GRB 050824: ROTSE-III Optical Limits
  36. GRB050820A: RTT150 optical observations
  37. GRB 050822: Swift-BAT refined analysis
  38. GRB050820: refined XRT analysis
  39. GRB050819: refined XRT analysis
  40. GRB050819: Swift XRT position
  41. GRB 050803: early Swift XRT analysis results
  42. GRB 050802: early Swift XRT analysis results
  43. GRB 050730: XRT refined analysis
  44. GRB 050724: Chandra Observations of the X-ray Afterglow
  45. GRB050724: Refined Radio Position
  46. GRB050724: VLT observations of the variable source
  47. GRB 050726: early Swift XRT analysis results
  48. GRB 050724: J-band observations
  49. GRB050724: Radio Observation
  50. GRB 050724: spectroscopy of object in the XRT error circle
  51. GRB 050724: Optical limit
  52. GRB 050724: optical and near-IR observations
  53. GRB 050724: Optical imaging/astrometry
  54. GRB 050724: RTT150 optical observations
  55. GRB 050724: early Swift XRT analysis results
  56. GRB 050724: possible host galaxy in DSS
  57. GRB 050714, optical observations
  58. GRB 050713b : Lulin R-band observations
  59. GRB 050701: Refined XRT analysis
  60. GRB 050701: Swift XRT afterglow position
  61. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  62. XRF 050509c: Optical monitoring
  63. GRB 050525a, Mid-Infrared Observations
  64. GRB 050607: Optical decay and spectral slope
  65. GRB050607,optical observation
  66. GRB050525: Optical observations
  67. XRF050522: NIR observations of XRT candidate
  68. XRF 050522: Swift XRT refined analysis
  69. GRB050522,optical observation
  70. RBO Observations of GRB050522
  71. XRF 050522: Swift XRT observation
  72. RBO Observations of GRB050520
  73. GRB 050509a: Swift-BAT refined analysis
  74. Swift Detection of GRB050509b: A short duration burst
  75. GRB 050504: Swift XRT position
  76. GRB (?) 050504: IR Observations, Intriguing Source
  77. GRB 050502a: RBO Observations
  78. GRB050502B Swift-BAT refined analysis
  79. GRB 050416: Swift XRT Position
  80. GRB 050412: Swift-BAT refined analysis
  81. GRB 050401: Optical limit
  82. GRB 050408: Optical limit
  83. GRB 050408: Swift XRT measurement of possible jet break
  84. GRB050319: radio observation
  85. Konus-Wind observation of GRB 050326
  86. GRB 050319: Optical observation
  87. GRB050223: analysis of the XMM-Newton observation
  88. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  89. GRB050309: CONCAM pre-trigger and trigger coincident optical
  90. GRB 050219b: CORRECTION: Swift XRT Position
  91. GRB 050219b: Swift XRT Position
  92. GRB050209: REM optical observations
  93. GRB050124: No Swift UVOT Detection of Afterglow Emission
  94. GRB050124,optical observation
  95. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  96. GRB050123: P60 Observations
  97. Fourth Epoch VLA observations of SGR 1806-20
  98. GRB041219; RXTE ASM Observations
  99. GRB041223: decay of the afterglow
  100. GRB041223: optical and NIR observations with REM

Advanced

Download all Circulars as a .tar.gz archive:
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