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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"

2744 results found.

  1. GRB 130518A: Swift XRT and UVOT possible afterglow
  2. GRB 130427A: Continued RATIR Optical and NIR Observations - Photometric Evidence for a New Component
  3. GRB 130427A: Skynet detections of a possible supernova
  4. GRB 130514B Swift-BAT observations
  5. GRB 130515A: GROND Observations
  6. GRB 130427A: Tautenburg 2nd epoch: No break, no clear SN
  7. GRB 130427A: host galaxy observations
  8. GRB 130505B: Swift Candidate Afterglow
  9. Refined IPN Triangulation of GRB 130502B
  10. Konus-Wind observation of GRB 130504C
  11. GRB 130504C: Swift-XRT observations
  12. GRB 130502B: possible TNG counterpart
  13. Trigger 555096: Swift detection of a possible burst
  14. GRB 130427A: Pan-STARRS 1 optical observations
  15. GRB 130427A: Predictions about the occurrence of a supernova
  16. GRB 130427A: GMRT radio detection
  17. GRB 130427A: photo-z of possible SDSS host galaxy
  18. GRB 130427A: high energy gamma-ray detection by AGILE
  19. GRB 130427A: Nishi-Harima NIR Observations
  20. GRB 130427A: P60 early nondetection
  21. Trigger 554491: Swift detection of a spike possibly from Sgr A*
  22. GRB 130327B: Swift/XRT source is not the afterglow
  23. Trigger 553930: Swift detection of a possible flare from HR 5110
  24. GRB 130408A, Swift-BAT refined analysis
  25. GRB 130306A: Confirmation of the X-ray Afterglow
  26. Swift Trigger 552142: a possible GRB
  27. GRB 130327A: PAIRITEL NIR Afterglow Candidate
  28. GRB 130315A: Swift detection of a burst
  29. GRB 130313A: Swift-XRT detection of a possible X-ray afterglow
  30. Swift XRT observations of GRB 130310A
  31. GRB 130306A: Swift Detection of a Possible Afterglow
  32. GBM trigger 383712005 (GRB 130228A?) : Possible high-energy photon emission in Fermi/LAT data
  33. GRB 130216A: possible radio counterpart is steady field source
  34. GRB 130216A: possible early detection at 15 GHz
  35. Swift/BAT trigger 547142 is new source Swift J1753.7-2544
  36. Swift Trigger 544381 is unlikely to be a GRB
  37. GRB 121209A: Early CARMA Observations
  38. GRB 121211A: Keck/LRIS redshift
  39. GRB 121202A: TAROT Calern observatory optical observations
  40. GRB 121031A: Fermi GBM detection
  41. GRB 121025A: Confirmation of the X-ray afterglow
  42. GRB 121027A: Swift/UVOT Possible Detection
  43. GRB 121025A: Swift-XRT observation
  44. Swift Trigger 536502 is likely a noise fluctuation in coincidence with SAX J1818.6-1703
  45. Trigger 535733: Swift possible detection of SAX J1828.5-1037
  46. Swift Trigger 535026: Optical decay confirmation with IAC80 and BOOTES-2/TELMA.
  47. GRB 121001A: possible optical counterpart
  48. Swift Trigger 535026: Galactic Transient or possible GRB
  49. GRB 120927A: GROND upper limits
  50. Swift Trigger 533836 is a new Galactic transient
  51. GRB 120909A: Swift-BAT refined analysis
  52. GRB 120821A: Swift/XRT observations
  53. GRB 120804A: Possible temporal break in the X-ray light-curve
  54. Swift Trigger 530581: GRB 120811A or a galactic transient
  55. GRB 120803A: optical upper limit
  56. GRB 120805A: 1.23m CAHA observations
  57. GRB 120803A: Swift-BAT refined analysis
  58. GRB 120803B: FTN possible afterglow candidate
  59. GRB 120803A: Swift detection of a possible burst
  60. Trigger 529076: Swift possible detection of SwJ1910.2-0546
  61. Swift Trigger 528925 is probably a noise fluctuation
  62. GRB 120724A: optical observation in Maidanak observatory
  63. GRB 120724A: Gemini-N tentative redshift
  64. GRB120714A: Swift/UVOT upper limits
  65. GRB 120711A: Swift/UVOT Observations
  66. GRB 120711A: a possible X-ray transient
  67. Swift Trigger 525554 is probably not a GRB
  68. Swift Trigger 524949: Noise fluctuation near a galaxy
  69. GRB 120521C: Early Tautenburg limits
  70. GRB 120514A: Swift-BAT refined analysis
  71. Fermi Trigger 358364818: BOOTES-4 observations
  72. GRB 120510B/Fermi Trigger 358364818: MASTER possible OT candidate
  73. GRB 120510A: Swift XRT and UVOT observations
  74. GRB 120422A: i-band re-brightening and possible SN detection
  75. GRB 120422A: optical observations
  76. GRB 120422A, the review of the sky area in plate archives
  77. GRB 120422A: Gemini redshift of candidate host
  78. GRB 120326A, the review of the sky area in plate archives
  79. GRB 120402A: optical upper limit
  80. GRB 120402A: Swift detection of a possible burst or noise
  81. GRB 120324A, the review of the sky area in plate archives
  82. Swift trigger 518853: MASTER-ICATE possible OT
  83. GRB 120327A: Gemini-South redshift
  84. GRB 120326A: Swift-BAT refined analysis
  85. GRB 120324A: Swift-BAT refined analysis
  86. GRB 120324A: Liverpool Telescope optical candidate
  87. GRB 120320A, the review of the sky area in plate archives
  88. GRB 120320A, Swift-BAT refined analysis
  89. GRB 111228A: possible detection of the SN with the TNG
  90. GRB 120302A: Swift XRT refined analysis
  91. GRB 120312A, the review of the sky area in plate archives
  92. GRB 120311A, the review of the sky area in plate archives
  93. GRB 120302A, the review of the sky area in plate archives
  94. GRB 120302A: Swift-BAT refined position and a possible XRT and UVOT counterpart
  95. GRB 120305A: Swift-BAT refined analysis
  96. GRB 120219A, the review of the sky area in plate archives
  97. GRB_120215, the_review_of_the_sky_area_in_plate_archives
  98. GRB 120212A: Errata of subject in GCNC 12936
  99. GRB 120202A, the review of the sky area in plate archives
  100. GRB 111228A, the review of the sky area in plate archives

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