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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"

28101 results found.

  1. GRB 070531: I-band observations from IAC80
  2. GRB 070531: Swift-XRT position
  3. GRB 070531: Swift detection of a burst
  4. GRB 070529: SARA upper limit
  5. Swift/UVOT refined analysis of GRB070529
  6. GRB 070529: Gemini Redshift
  7. GRB 070529: Swift-XRT refined analysis
  8. GRB 070529: Swift detection of a burst with an optical aterglow
  9. GRB 070412: Deep Keck imaging
  10. Swift trigger 280447 is probably a Galactic transient
  11. GRB 070518, deep LBT photometry
  12. GRB070521: Second Epoch Gemini Imaging
  13. GRB070521: NIR observations
  14. GRB070520B: NIR observations
  15. GRB 070521: Swift/UVOT Upper Limits
  16. GRB 070521: Swift-XRT refined analysis
  17. GRB 070521: Keck imaging
  18. GROND upper limits of GRB 070521
  19. GRB 070521: SARA upper limit
  20. GRB 070521: Subaru observations and possible host detection
  21. GRB070518: Optical/NIR observation
  22. GRB 070520B: Swift/UVOT Upper Limits
  23. GRB 070520A: Subaru Observations
  24. GRB 070520A: Swift UVOT Upper Limits
  25. GRB 070520B: Swift-XRT refined analysis
  26. GRB 070521: optical limit by Pi of the Sky
  27. GRB070521: P200 Observations
  28. GRB070521 : Faulkes Telescope North Observations
  29. GRB 070521: TAROT La Silla observatory optical observations
  30. GRB070521: Bright SDSS Galaxy Near XRT Error Circle
  31. GRB 070521: Swift detection of a burst
  32. GRB 070520A: MITSuME Akeno optical upper limits
  33. GRB 070520A: Swift-XRT refined analysis
  34. GRB 070518: TNG observations
  35. GRB 070520B: Swift detection of a burst
  36. GRB 070520: Swift detection of a burst
  37. VLA observation of GRB 070518
  38. GRB 070518: Swift-XRT refined analysis
  39. GRB 070517: Gemini optical imaging
  40. GRB070518: UVOT refined analysis
  41. GRB070518: OSN observation
  42. GRB 070518: Swift detection of a burst with optical afterglow
  43. GRB070517: Swift-XRT Refined Analysis
  44. GRB 070517: Swift detection of a burst
  45. GRB 070509: objects inside XRT error circle
  46. GRB070419A: optical observations
  47. GRB 070419A, Deep LBT photometry
  48. GRB 070509: Swift/UVOT Upper Limits
  49. GRB 070510: Swift detection of a possible burst
  50. GRB070509: Swift-XRT Refined Analysis
  51. GRB 070508: OA fading and tentative redshift
  52. GRB 070509: REM observations
  53. GRB 070509: Swift detection of a burst
  54. GRB 070509: ROTSE-III Optical Limits
  55. GRB070508: Swift/UVOT Observations
  56. GRB 070508, SMARTS optical afterglow observation
  57. GRB 070508: Multicolor optical observations and possible redshift limit
  58. GRB 070508: Swift-XRT refined analysis
  59. GRB 070508: Optical afterglow detection
  60. GRB 070508: REM observations
  61. GRB 070508: Swift detection of an intense burst with an optical counterpart
  62. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  63. GRB070506: Swift/UVOT Observations
  64. GRB070506: Swift XRT refined analysis
  65. GRB 070506: Swift detection of a burst with optical afterglow
  66. GRB 070412, deep LBT imaging
  67. GRB 070429A: Swift XRT further analysis
  68. GRB070429B: VLT observations
  69. GRB 070429A: optical observations
  70. GRB070429B: position correction
  71. GRB 070309: Swift-XRT afterglow confirmation
  72. GRB070429B: possible host galaxy detection
  73. VLA observation of GRB 070429B
  74. Swift/UVOT observations of GRB070429B
  75. Swift/UVOT observations of GRB070429A
  76. GRB 070429A: Swift XRT refined analysis
  77. GRB 070429A: optical and NIR observations
  78. GRB 070429B: Swift XRT refined analysis
  79. GRB 070429B: ROTSE-III Optical Limits
  80. GRB 070429B: Swift detection of a short burst
  81. GRB 070429: ROTSE-III Optical Limits
  82. GRB 070429: Swift detection of a burst
  83. LT monitoring of GRB070412
  84. GRB 070427: Swift detection of a burst
  85. GRB 070411, further deep LBT photometry
  86. GRB 070411: Late-time Keck imaging
  87. GRB 070420, SMARTS optical/IR afterglow observations
  88. GRB 070411, deep LBT photometry
  89. GRB 070411: break in the optical light curve
  90. GRB070419A: Kuiper Optical detection
  91. GRB070419a: Swift UVOT observations
  92. GRB 070420: optical rebrightening observed at Mt. John
  93. GRB 070420: Swift XRT refined analysis
  94. GRB070420: Swift UVOT continuing observations
  95. GBR 070419A: Swift/XRT refined analysis
  96. GRB 070420: TAROT La Silla observatory optical observations
  97. GRB 070420: NIR and optical afterglow confirmed
  98. GRB 070420: Swift detection of a burst with optical afterglow
  99. GRB 070419A: MITSuME Okayama Observations
  100. GRB 070419A: Early Super-LOTIS Observations

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