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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"

27394 results found.

  1. GRB 070628: TAROT La Silla observatory optical observations
  2. Swift UVOT Observations of GRB 070628
  3. OT20050728 was not an optical GRB afterglow
  4. GRB 070616 : WIDGET simultaneous optical observations
  5. GRB 070616: Suzaku/WAM observation of the prompt emission
  6. GRB070621: RTT150 optical observations
  7. GRB 070621: VLT optical observations
  8. GRB 070621: Swift/UVOT Upper Limits
  9. Keck Laser Guide Star Adaptive Optics Imaging of GRB 070621
  10. GRB 070621: Swift-BAT refined analysis
  11. GRB070621: Swift XRT refined analysis
  12. GRB 070621: Gemini South optical imaging
  13. GRB 070621: UVOT-enhanced XRT position
  14. Observations of GRB070612A at Calar Alto
  15. GRB 070621: NOT observations
  16. GRB070621: OPTIMA-Burst optical upper limit
  17. GRB 070621: TAROT Calern observatory optical observations
  18. GRB 070621: Watcher Observations
  19. GRB 070621: Swift detection of a burst
  20. GMRT upper limit of GRB 070610/SWIFT J195509.6+261406 in 610 MHz
  21. Swift/UVOT detection of GRB070616 optical afterglow.
  22. GRB 070612A: NOT observations
  23. GRB070616: Optical Observation by MITSuME Okayama
  24. GRB 070616, Swift-BAT further refined analysis
  25. GRB 070616: BTA optical observations
  26. GRB 070616: TLS observation
  27. Swift XRT observations of the INTEGRAL burst GRB070615: Possible
  28. GRB 070616: Swift detection of a burst
  29. GRB 070612B: optical observations
  30. UVOT Observations of INTEGRAL burst GRB070615
  31. VLA upper limit on GRB 070610
  32. GRB 070615
  33. SWIFT J195509.6+261406 (GRB 070610): further observations
  34. GRB 070612A: Super-LOTIS observations
  35. GRB 070612A: Rapid Decay
  36. GRB 070612A: Suzaku/WAM observation of the prompt emission
  37. SWIFT J195509.6+261406 / GRB 070610: OPTIMA-Burst observations
  38. GRB070612A: MITSuME Okayama Observation
  39. GRB 070612A: continued SARA observations
  40. GRB 070611: Watcher Observations
  41. Swift Trigger 282176 is Cygnus X-1
  42. GRB 070612A: P60 Confirmation of Afterglow and An Underlying, Nearby
  43. GRB 070612B: SARA upper limit
  44. GRB 070612B, Swift-BAT refined analysis
  45. GRB 070612A, Swift-BAT refined analysis
  46. SWIFT J195509.6+261406 / GRB 070610: SWIFT continued observations
  47. GRB 070612B: Swift/UVOT upper limits
  48. GRB 070612B: FRAM limit
  49. GRB070612B: P60 Observations
  50. GRB 070612A: SARA detection of possible OT
  51. GRB 070610: TAROT Calern observatory optical observations
  52. GRB 070610: MITSuME OAO optical upper limit
  53. GRB070612 - SDSS Pre-Burst Observations
  54. GRB 070612: Swift detection of a burst
  55. GRB 070610: OPTIMA-Burst detection of continued strong flaring activity
  56. GRB 070610: SARA upper limit
  57. GRB 070610: Swift-XRT refined analysis
  58. GRB 070611: Swift/UVOT Observations
  59. GRB 070611: Swift-XRT refined analysis
  60. GRB 070611, Swift-BAT refined analysis
  61. GRB 070610: Optical observations from OSN
  62. GRB 070610: Watcher Observations
  63. GRB 070611: ROTSE-III Detection of Late Rising Optical Counterpart
  64. GRB 070611: ROTSE-III Optical Limits
  65. GRB 070610: Swift-UVOT Upper Limits
  66. GRB 070610: OPTIMA-Burst high-time-resolution optical observations
  67. GRB 070610, Swift-BAT refined analysis
  68. GRB 070412: TAROT Calern observatory optical observations
  69. GRB 070411: TAROT Calern observatory optical observations
  70. GRB070520B: optical observations
  71. GRB070520: optical observation
  72. GRB070518: optical observation
  73. GRB070521: optical observation
  74. GRB 070531: NOT nIR observations
  75. GRB 070531: Swift-BAT refined analysis
  76. GRB 070531: I-band observations from IAC80
  77. GRB 070531: Liverpool Telescope Optical Observations
  78. GRB 070529: SARA upper limit
  79. Swift/UVOT refined analysis of GRB070529
  80. GRB 070529: Optical aterglow from MIRO
  81. GRB 070529: Swift-XRT refined analysis
  82. GRB 070529, Swift-BAT refined analysis
  83. GRB 070529: Xinglong TNT Optical Upper Limit
  84. GRB 070529: Swift detection of a burst with an optical aterglow
  85. GRB 070412: Deep Keck imaging
  86. Swift trigger 280447 is probably a Galactic transient
  87. GRB 070518, deep LBT photometry
  88. Konus-Wind observation of GRB 070521
  89. GRB070521: Second Epoch Gemini Imaging
  90. GRB 070521: Swift/UVOT Upper Limits
  91. GRB 070521, optical observation
  92. GRB 070521: Swift-XRT refined analysis
  93. GRB 070521: Keck imaging
  94. GRB070521: Gemini Observations
  95. GROND upper limits of GRB 070521
  96. GRB 070520B: SARA upper limit
  97. GRB 070520A: SARA upper limit
  98. GRB 070521: SARA upper limit
  99. GRB 070521: Subaru observations and possible host detection
  100. GRB 070520B: Swift/UVOT Upper Limits

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