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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"

2623 results found.

  1. GRB 130327B: Swift/XRT source is not the afterglow
  2. Trigger 553930: Swift detection of a possible flare from HR 5110
  3. GRB 130408A, Swift-BAT refined analysis
  4. GRB 130306A: Confirmation of the X-ray Afterglow
  5. Swift Trigger 552142: a possible GRB
  6. GRB 130327A: PAIRITEL NIR Afterglow Candidate
  7. GRB 130315A: Swift detection of a burst
  8. GRB 130313A: Swift-XRT detection of a possible X-ray afterglow
  9. Swift XRT observations of GRB 130310A
  10. GRB 130306A: Swift Detection of a Possible Afterglow
  11. GBM trigger 383712005 (GRB 130228A?) : Possible high-energy photon emission in Fermi/LAT data
  12. GRB 130216A: possible radio counterpart is steady field source
  13. GRB 130216A: possible early detection at 15 GHz
  14. Swift/BAT trigger 547142 is new source Swift J1753.7-2544
  15. Swift Trigger 544381 is unlikely to be a GRB
  16. GRB 121209A: Early CARMA Observations
  17. GRB 121211A: Keck/LRIS redshift
  18. GRB 121202A: TAROT Calern observatory optical observations
  19. GRB 121031A: Fermi GBM detection
  20. GRB 121025A: Confirmation of the X-ray afterglow
  21. GRB 121027A: Swift/UVOT Possible Detection
  22. GRB 121025A: Swift-XRT observation
  23. Swift Trigger 536502 is likely a noise fluctuation in coincidence with SAX J1818.6-1703
  24. Trigger 535733: Swift possible detection of SAX J1828.5-1037
  25. Swift Trigger 535026: Optical decay confirmation with IAC80 and BOOTES-2/TELMA.
  26. GRB 121001A: possible optical counterpart
  27. Swift Trigger 535026: Galactic Transient or possible GRB
  28. GRB 120927A: GROND upper limits
  29. Swift Trigger 533836 is a new Galactic transient
  30. GRB 120909A: Swift-BAT refined analysis
  31. GRB 120821A: Swift/XRT observations
  32. GRB 120804A: Possible temporal break in the X-ray light-curve
  33. Swift Trigger 530581: GRB 120811A or a galactic transient
  34. GRB 120803A: optical upper limit
  35. GRB 120805A: 1.23m CAHA observations
  36. GRB 120803A: Swift-BAT refined analysis
  37. GRB 120803B: FTN possible afterglow candidate
  38. GRB 120803A: Swift detection of a possible burst
  39. Trigger 529076: Swift possible detection of SwJ1910.2-0546
  40. Swift Trigger 528925 is probably a noise fluctuation
  41. GRB 120724A: optical observation in Maidanak observatory
  42. GRB 120724A: Gemini-N tentative redshift
  43. GRB120714A: Swift/UVOT upper limits
  44. GRB 120711A: Swift/UVOT Observations
  45. GRB 120711A: a possible X-ray transient
  46. Swift Trigger 525554 is probably not a GRB
  47. Swift Trigger 524949: Noise fluctuation near a galaxy
  48. GRB 120521C: Early Tautenburg limits
  49. GRB 120514A: Swift-BAT refined analysis
  50. Fermi Trigger 358364818: BOOTES-4 observations
  51. GRB 120510B/Fermi Trigger 358364818: MASTER possible OT candidate
  52. GRB 120510A: Swift XRT and UVOT observations
  53. GRB 120422A: i-band re-brightening and possible SN detection
  54. GRB 120422A: optical observations
  55. GRB 120422A, the review of the sky area in plate archives
  56. GRB 120422A: Gemini redshift of candidate host
  57. GRB 120326A, the review of the sky area in plate archives
  58. GRB 120402A: optical upper limit
  59. GRB 120402A: Swift detection of a possible burst or noise
  60. GRB 120324A, the review of the sky area in plate archives
  61. Swift trigger 518853: MASTER-ICATE possible OT
  62. GRB 120327A: Gemini-South redshift
  63. GRB 120326A: Swift-BAT refined analysis
  64. GRB 120324A: Swift-BAT refined analysis
  65. GRB 120324A: Liverpool Telescope optical candidate
  66. GRB 120320A, the review of the sky area in plate archives
  67. GRB 120320A, Swift-BAT refined analysis
  68. GRB 111228A: possible detection of the SN with the TNG
  69. GRB 120302A: Swift XRT refined analysis
  70. GRB 120312A, the review of the sky area in plate archives
  71. GRB 120311A, the review of the sky area in plate archives
  72. GRB 120302A, the review of the sky area in plate archives
  73. GRB 120302A: Swift-BAT refined position and a possible XRT and UVOT counterpart
  74. GRB 120305A: Swift-BAT refined analysis
  75. GRB 120219A, the review of the sky area in plate archives
  76. GRB_120215, the_review_of_the_sky_area_in_plate_archives
  77. GRB 120212A: Errata of subject in GCNC 12936
  78. GRB 120202A, the review of the sky area in plate archives
  79. GRB 111228A, the review of the sky area in plate archives
  80. GRB 111228A: Possible host detected by Swift/UVOT
  81. GRB 120116A, the review of the sky area in plate archives
  82. GRB 120121A: Swift-XRT position
  83. GRB 120102A, the review of the sky area in plate archive
  84. GRB 110915B, the review of the sky area in plate archives
  85. GRB 111225A, the review of the sky area in plate archives
  86. GRB 111222A, the review of the sky area in plate archives
  87. GRB 111211A: Detection of the SN with the 10.4m GTC
  88. GRB 120102A: Swift-BAT refined analysis
  89. GRB 110915A, the review of the sky area in plate archives
  90. GRB 111229A: Swift detection of a burst
  91. GRB 111228A: Possible host galaxy in the SDSS arhive
  92. GRB 111225A: Swift-XRT refined Analysis
  93. GRB 111205A: Confirmation of X-ray Afterglow
  94. Possible detection of pre-trigger X-ray emission from GRB 111215A by MAXI/GSC
  95. GRB 111215A: Swift-BAT refined analysis
  96. GRB 111201A, the review of the sky area in plate archive
  97. GRB 111209A: VLT/X-shooter redshift
  98. GRB 111205A: GROND observations
  99. GRB 111123A: optical upper limit in CrAO: correction to the GCN circ. 12613
  100. GRB 111123A, Swift-BAT refined analysis

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