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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"

6188 results found.

  1. GRB 100901A: TLS Observations: Break?
  2. GRB 100901A: Swift-XRT Team refined analysis
  3. GRB 100901A - NOT optical observation
  4. GRB 100901A: Swift-BAT refined analysis
  5. GRB 100725B: Maidanak optical upper limit
  6. GRB 100823A: Swift XRT refined analysis
  7. GRB 100814B: Fermi GBM detection
  8. GRB 100816A: Fermi GBM observation
  9. GRB100816A Swift-XRT refined analysis
  10. GRB 100816A: CQUEAN riz-band Detection, Host Galaxy?
  11. GRB 100814A: Fermi GBM observation
  12. GRB 100814A: Swift-XRT refined analysis
  13. GRB 100807A: Swift XRT refined analysis
  14. GRB 100805A: Swift-XRT Refined Analysis
  15. GRB 100805A: GRAS 002 optical observations
  16. GRB 100802A: Fermi GBM observation
  17. GRB 100728B: optical photometry of ISON-NM
  18. GRB 100713A: second epoch Maidanak optical observation
  19. GRB 100802A: XRT refined analysis
  20. GRB 100728B: Lick Observations
  21. GRB 100728B: Swift-XRT Refined Analysis
  22. GRB 100728B: Fermi GBM observation
  23. GRB 100728A: Swift-XRT refined analysis
  24. GRB 100728A: Fermi GBM observation
  25. GRB 100727A: Swift XRT refined analysis
  26. GRB 100727A: Fermi GBM observation
  27. GRB100727A: MOA optical upper limit
  28. GRB 100725B: refined XRT analysis
  29. GRB 100725B: Swift/UVOT Upper Limits
  30. GRB 100725A: Swift XRT refined analysis
  31. GRB 100724B: Fermi LAT and GBM analysis
  32. GRB 100724B: Fermi GBM detection
  33. GRB 100724A: Swift XRT refined analysis
  34. GRB 100722A: Fermi GBM detection
  35. GRB 100713A: optical observation in Maidanak
  36. GRB 100713A: Swift XRT refined analysis
  37. GRB 100713A : IRSF/SIRIUS NIR upper limits
  38. GRB100713A: Swift X-ray afterglow detection
  39. GRB 100707A: Fermi LAT detection
  40. GRB 100707A: Fermi GBM detection
  41. GRB 100628A: Swift XRT/UVOT refined analysis
  42. GRB 100704A: Swift XRT refined analysis
  43. GRB 100704A: Fermi GBM observation
  44. GRB 100625A: Fermi GBM detection
  45. GRB 100628A: Swift XRT refined position
  46. GRB100628A : MOA optical upper limit
  47. GRB 100628A: Swift XRT detection of a possible X-ray afterglow
  48. GRB 100625A : IRSF/SIRIUS NIR upper limit
  49. GRB 100625A: Swift-XRT Team refined analysis
  50. GRB 100621A: IRSF/SIRIUS NIR Observation
  51. GRB 100621A: Swift XRT refined analysis
  52. GRB 100619A: Fermi GBM detection
  53. GRB 100619A: Swift/UVOT Upper Limits
  54. GRB 100619A: Swift-XRT refind analysis
  55. GRB 100615A: Swift-XRT refined analysis
  56. GRB 100614A: Swift-XRT refined analysis
  57. GRB 100615A: PAIRITEL NIR Upper Limits
  58. GRB 100606A Swift-XRT refined analysis
  59. GRB 100606A: Prompt enhanced Swift-XRT position
  60. GRB 100111A: Maidanak optical observations
  61. Swift UVOT and UVOT-enhanced XRT position for GRB 100528A
  62. GRB 100528A: Fermi GBM observation
  63. GRB 100526B: Swift-XRT confirmation of fading afterglow
  64. GRB 100526A: Swift XRT refined analysis
  65. GRB 100522A: Fermi GBM observation
  66. GRB 100522A: Swift XRT refined analysis
  67. GRB 100522A: NIR observations from CAHA
  68. GRB 100518A: Swift-XRT refined analysis
  69. GRB 100518A: Swift target of opportunity observation of the INTEGRAL burst
  70. GRB 100514A: Swift XRT refined analysis
  71. GRB 100513A: Swift XRT refined analysis
  72. GRB 100513A: Lick observations and R-band dropout
  73. GRB 100513A: PAIRITEL continued observations and confirmation of fading
  74. GRB 100513A: PAIRITEL NIR afterglow candidate
  75. GRB 100510A: Fermi GBM detection/observation
  76. GRB 100511A: Fermi GBM detection/observation
  77. Swift-BAT trigger 421695 is likely not astrophysical
  78. GRB 100508A: Swift-XRT Refined analysis
  79. GRB 100504A: Fermi GBM observation
  80. GRB 100418A: Flattening of the Swift/UVOT Optical Light Curve
  81. GRB 100504A: Swift-XRT refined analysis
  82. GRB 100503A: Fermi GBM detection
  83. GRB 100427A: Swift XRT and UVOT Upper Limits
  84. GRB 100425A: Swift XRT refined analysis
  85. GRB 100424A: PAIRITEL NIR Upper Limits
  86. GRB 100424A: Prompt enhanced Swift-XRT position.
  87. GRB 100418A: Continued PAIRITEL NIR Observations
  88. GRB 100418A: Continuing Swift/UVOT Observations
  89. GRB 100418A: further GROND observations and light curve fit
  90. GRB 100418A: RTT150 optical observations
  91. GRB 100420A: XRT refined analysis
  92. GRB 100418A: RTT150 observations during the optical afterglow maximum
  93. GRB 100418A PAIRITEL NIR Observations
  94. GRB 100418A: Swift-XRT Refined Analysis
  95. GRB100414A: SAO RAS optical observations
  96. GRB 100413B: Swift Confirmation of Burst
  97. GRB 100414A: Swift-XRT detection of a possible X-ray afterglow
  98. GRB 100414A: Fermi GBM detection
  99. GRB100414A: Fermi LAT detection
  100. GRB 100413A: Swift/UVOT Upper Limits

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