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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"

37513 results found.

  1. Swift Observations of GRB 140508A
  2. GRB 140512A: Optical observations from the 2.5 m NOT
  3. GRB 140428A: GROND afterglow confirmation
  4. GRB 140512A: Mondy optical detection
  5. GRB 140512A: MASTER OT decay and early light curve
  6. GRB 140512A: Swift detection of a burst with an optical counterpart
  7. GRB 140512A: MASTER optical observations
  8. GRB 140423A: Mondy optical observations
  9. GRB 140508A: Continued RATIR Optical and NIR Observations
  10. Fermi GBM Trigger 140429551 - Detection of a burst from SGR 1806-20
  11. GRB 140508A: ​HCT spectroscopy
  12. GRB 140508A: Swift/UVOT Detection
  13. GRB 140509B: MAXI/GSC detection
  14. GRB 140509A: Swift/UVOT Detection and photo-z
  15. GRB 140509A: Swift-BAT refined analysis
  16. VHE gamma-ray observations by MAGIC of SWIFT Trigger 596958
  17. GRB 140509A: Swift-XRT refined Analysis
  18. GRB 140508A: RATIR Optical and NIR Observations
  19. GRB 140508A: Optical Observations via Virtual Telescope
  20. Konus-Wind observation of GRB 140508A
  21. GRB 140509A: Enhanced Swift-XRT position
  22. GRB 140508A: Swift-XRT observations
  23. GRB 140508A: WHT spectroscopy
  24. GRB 140509A: Swift detection of a burst with an optical counterpart
  25. GRB 140508A: NOT photometry and spectroscopy
  26. GRB 140508A: SAO RAS and MASTER photometric and spectroscopic observations
  27. GRB 140508A: 1.23m CAHA BVRI-band observations
  28. GRB 140508A: iPTF optical transient candidate
  29. IPN triangulation of GRB 140508A
  30. GRB 140508A: Fermi GBM detection
  31. Konus-Wind observation of GRB 140506A
  32. GRB 140430A: MITSuME Akeno upper limits
  33. GRB 140502A: ISON-NM early optical limit
  34. GRB 140506A: Fermi GBM Detection
  35. GRB 140506A: Swift/UVOT Detection
  36. GRB 140506A: Swift-BAT refined analysis
  37. GRB 140506A: VLT/X-shooter spectroscopy
  38. GRB 140506A: Swift-XRT refined Analysis
  39. GRB 140506A: Enhanced Swift-XRT position
  40. GRB 140506A: Swift detection of a burst with an optical counterpart
  41. Konus-Wind observation of GRB 140423A
  42. GRB 140430A: iTelescope.Net T16 Optical Observation
  43. GRB 140430A: r'-band STELLA-I observations
  44. GRB 140502A: Swift/UVOT Upper Limits
  45. GRB 140502A: MITSuME Okayama upper limits
  46. GRB 140502A: Swift-BAT refined analysis
  47. GRB 140502A: Swift-XRT refined Analysis
  48. GRB 140502A: Enhanced Swift-XRT position
  49. GRB 140430A: BVR-band IAC80 observations
  50. Swift Trigger 597860 is probably not a GRB
  51. GRB 140502A: Fermi GBM observation
  52. GRB 140502A: Swift detection of a burst
  53. GRB 140430A: Further VATT Optical Observations
  54. GRB 140430A: Swift-BAT refined analysis
  55. GRB 140501A: Fermi GBM detection
  56. GRB 140430A: Swift/UVOT Observations
  57. GRB 140430A: Swift-XRT refined Analysis
  58. GRB 140430A: VATT Optical Observations
  59. GRB 140430A: Enhanced Swift-XRT position
  60. GRB 140430A: VLT/X-shooter redshift
  61. GRB 140430A: NOT optical observations
  62. GRB 140430A : Liverpool Telescope optical afterglow observations
  63. GRB 140428A: GROND observations
  64. GRB140430A: Swift detection of a burst with an optical counterpart
  65. GRB 140428B: Fermi GBM observation
  66. Konus-Wind observation of GRB 140428B
  67. GRB 140428A: Swift/UVOT Upper Limits
  68. GRB 140428A: Swift-BAT refined analysis
  69. GRB 140423A: RTT150 optical observations
  70. IPN Triangulation of GRB 140428B (short/hard)
  71. GRB 140428A: 1.5m OSN I-band detection
  72. GRB 140428A: Keck redshift estimate
  73. GRB 140428A: Keck detection of a red optical afterglow candidate
  74. GRB 140428A: NOT observations
  75. GRB 140428A: Swift-XRT detection of a source
  76. GRB 140428A: Swift Detection of a Possible Burst
  77. GRB 140423A: MITSuME Akeno upper limits
  78. GRB 140423A Third epoch pODI photometry
  79. GRB 140423A: Continued RATIR Optical and NIR Observations
  80. GRB 140423A: MITSuME Akeno Optical observation
  81. GRB 140413A: GROND Afterglow Confirmation
  82. DG CVn: optical observations
  83. GRB 140423A: RATIR Optical and NIR Observations
  84. GRB 140423A: NOT Afterglow Observations
  85. GRB 140419A: Continued Mondy optical observations
  86. GRB 140423A: Nishi-Harima NIR Observations
  87. GRB 140423A: TNG NIR observations
  88. GRB 140423A pODI/WIYN afterglow photometry
  89. GRB 140423A, Optical Observations
  90. GRB 140423A: Kanata/HONIR Optical and NIR Observations
  91. GRB 140423A: Swift-XRT refined Analysis
  92. GRB 140423A: Swift-BAT refined analysis
  93. GRB 140423A: MITSuME Okayama Optical Observation
  94. GRB 140423A: Further Observations with Swift/UVOT
  95. GRB 140423A: KAIT Optical Detection
  96. GRB 140423A: Enhanced Swift-XRT position
  97. GRB 140423A: Nanshan optical upper limit
  98. GRB 140423A: P60 Observations
  99. GRB 140423A: Fermi GBM observation
  100. GRB 140423A: KWFC z-band photometry

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