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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"

22917 results found.

  1. Swift XRT follow-up observations of GRB071028B
  2. GRB071112C Xinglong_TNT_and_EST_afterglow observations
  3. GRB 071112C: Optical and NIR afterglows observed with KANATA
  4. GRB 071112B: ROTSE-III Rapid Optical Limits
  5. GRB 071112C: Swift detection of a burst with an optical counterpart
  6. GRB 071112B: Swift detection of a short hard burst
  7. GRB 071112: Swift detection of a possible burst
  8. GRB071109: Super-LOTIS observations
  9. Swift/UVOT initial analysis of GRB071109
  10. GRB 071109: further Swift-XRT analysis
  11. GRB 071109: TAROT Calern observatory optical observations
  12. GRB 071109: Swift-XRT possible X-ray counterpart
  13. GRB 071104: Possible Swift UVOT Afterglow Candidate
  14. GRB 071104: Swift-XRT position
  15. GRB071010b: optical observation
  16. Swift XRT and UVOT observations of GRB071028B
  17. GRB071101: Optical and NIR upper limits by KANATA
  18. GRB0711101: Two new source from Xinglong TNT observation
  19. GRB 071101: TAROT Calern observatory optical observations
  20. GRB071101 LOAO B,V,R,I observation
  21. GRB 071101: a nearby galaxy
  22. GRB 071101: Swift detection of a burst
  23. GRB 071031: Swift/UVOT detection of afterglow
  24. GRB 071031: Swift-XRT Team refined analysis
  25. GRB 071020: MITSuME Akeno optical observations
  26. GRB 071031: REM NIR and Optical observation
  27. GRB 071031: Swift detection of a burst with an optical counterpart
  28. GRB 071028B Swift-BAT detection of a burst
  29. GRB071025: Optical+NIR observations
  30. GRB 071028: SARA observations of variable source
  31. Swift UVOT upper limits to GRB071028
  32. GRB071028: Xinglong EST V-band upper limit
  33. GRB 071028: Swift-XRT Team refined analysis
  34. GRB 071028: Swift detection of a burst
  35. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  36. GRB071021: MARGE Optical Limits
  37. GRB071020, optical upper limit
  38. GRB 071025: SARA VRI upper limits
  39. GRB 071025 Milagro GeV/TeV Observations
  40. GRB071025: Optical Pre-imaging from Palomar
  41. Swift UVOT upper limits
  42. GRB071025: Xinglong TNT I-band upper limit
  43. GRB 071025: Swift-XRT Team refined analysis
  44. GRB 071025, Swift-BAT refined analysis
  45. GRB071021 : CFHT Ks-band observation
  46. GRB 071025a: PAIRITEL observations
  47. GRB 071025: Swift detection of a burst
  48. GRB 071021: R-band detection and analysis
  49. GRB071021: Optical+NIR observations
  50. Possible radio detection of GRB 071021 with the VLA
  51. GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
  52. GRB 071020: SARA observations
  53. Radio detection of GRB 071020 with the VLA
  54. GRB071021: MITSuME Okayama Optical Upper Limits
  55. GRB 071021: Magellan i-band observation
  56. GRB 071021: Magellan R-band observation
  57. GRB 071021: Z-band detection
  58. GRB071018: 2nd epoch obsevations of Xinglong TNT
  59. GRB 071021: Xinglong TNT optical Upper Limit
  60. GRB 071021 : Lulin R-band limit
  61. GRB 071021: Swift detection of a burst
  62. GRB071020A: Xinglong TNT Optical afterglow observations
  63. GRB 071020, Swift-BAT refined analysis
  64. GRB 071020A: IR Imaging with PAIRITEL
  65. GRB071020 - SDSS Pre-burst Observations
  66. GRB 071020: Swift detection of a bright burst
  67. GRB 071018: Mercator Telescope optical observations
  68. Swift autonomous slewing re-enabled
  69. GRB 071018: SARA observations
  70. GRB 071018: Swift-XRT observation
  71. GRB 071017 - Swift XRT observations
  72. GRB 071018: Possible OT from Xinglong TNT observation
  73. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  74. GRB 071018, Swift-BAT refined analysis
  75. GRB 071018?: Swift detection of a possible burst
  76. GRB 071013: 3rd TLS Epoch - constraints on variability
  77. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  78. GRB071013: optical observations
  79. GRB 071011: MITSuME Optical Observations
  80. GRB 070920A: deep optical observations at the NOT
  81. GRB 071010B: Keck/LRIS Photometry
  82. GRB 071013: TLS Upper Limit
  83. VLA non-detection of GRB 071011
  84. GRB 071013: Optical observations
  85. GRB 071013: optical observations at NOT
  86. GRB071010B, BVRcIc field calibration
  87. GRB 20071013: Xinglong TNT optical Upper Limit
  88. GRB 071013: Swift detection of a burst
  89. GRB 071010C Swift-BAT detection of a burst
  90. GRB 071011: Optical Limit after 13.95hrs
  91. GRB 071010B correction to GCN 6892 optical observations
  92. GRB 071011: Swift-XRT refined analysis
  93. VLA non-detection of GRB 071010A
  94. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  95. GRB 071011: Confirmation of P60 optical afterglow
  96. GRB 071010B: Optical Detection
  97. GRB 071011: Kanazawa Optical limits
  98. GRB 071011: P60 Optical Afterglow Candidate
  99. GRB 071011: MARGE Optical Limits
  100. GRB 071010B: Super-LOTIS upper limit

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