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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"

20378 results found.

  1. GRB 071109: further Swift-XRT analysis
  2. GRB 071109: TAROT Calern observatory optical observations
  3. GRB 071109: Swift-XRT possible X-ray counterpart
  4. GRB 071104: Swift-XRT Team Refined Analysis
  5. GRB 071104: Possible Swift UVOT Afterglow Candidate
  6. GRB 071104: Swift-XRT position
  7. Swift XRT and UVOT observations of GRB071028B
  8. GRB 071101: Swift-XRT Team refined analysis
  9. GRB071101: Optical and NIR upper limits by KANATA
  10. GRB0711101: Two new source from Xinglong TNT observation
  11. GRB 071101: TAROT Calern observatory optical observations
  12. GRB071101 LOAO B,V,R,I observation
  13. GRB 071031: Swift-XRT Team refined analysis
  14. GRB 071020: MITSuME Akeno optical observations
  15. GRB 071031: REM NIR and Optical observation
  16. GRB 071031: Swift detection of a burst with an optical counterpart
  17. GRB 071028B Swift-BAT detection of a burst
  18. GRB 071028: SARA observations of variable source
  19. Swift UVOT upper limits to GRB071028
  20. GRB071028: Xinglong EST V-band upper limit
  21. GRB 071028: Swift-XRT Team refined analysis
  22. GRB 071028: Swift detection of a burst
  23. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  24. GRB071021: MARGE Optical Limits
  25. GRB071020, optical upper limit
  26. GRB 071025: SARA VRI upper limits
  27. GRB 071025: SQIID JHK photometry
  28. Swift UVOT upper limits
  29. GRB071025: Xinglong TNT I-band upper limit
  30. GRB 071025: Swift-XRT Team refined analysis
  31. GRB071021 : CFHT Ks-band observation
  32. GRB 071025a: PAIRITEL observations
  33. GRB071025: REM NIR afterglow
  34. GRB 071025: Swift detection of a burst
  35. GRB 071021: R-band detection and analysis
  36. GRB 071020: BTA spectroscopy
  37. Possible radio detection of GRB 071021 with the VLA
  38. GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
  39. GRB 071020: SARA observations
  40. Radio detection of GRB 071020 with the VLA
  41. GRB071021: MITSuME Okayama Optical Upper Limits
  42. GRB 071021: Z-band detection
  43. GRB071018: 2nd epoch obsevations of Xinglong TNT
  44. GRB 071021: Xinglong TNT optical Upper Limit
  45. GRB 071021 : Lulin R-band limit
  46. GRB 071021: Swift detection of a burst
  47. GRB071020A: Xinglong TNT Optical afterglow observations
  48. GRB 071020A: IR Imaging with PAIRITEL
  49. GRB071020 - SDSS Pre-burst Observations
  50. GRB 071020: Swift detection of a bright burst
  51. GRB 071018: Mercator Telescope optical observations
  52. GRB 071018: SARA observations
  53. GRB 071018: Swift-XRT observation
  54. GRB 071017 - Swift XRT observations
  55. GRB 071018: Possible OT from Xinglong TNT observation
  56. GRB 071010B: Light Curve Break Confirmed
  57. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  58. GRB 071018, Swift-BAT refined analysis
  59. GRB 071013: 3rd TLS Epoch - constraints on variability
  60. GRB 071013: TNT optical data refined analysis
  61. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  62. GRB 071011: MITSuME Optical Observations
  63. GRB 070920A: deep optical observations at the NOT
  64. GRB 071010B: Keck/LRIS Photometry
  65. GRB 071013: TLS Upper Limit
  66. VLA non-detection of GRB 071011
  67. GRB 071013: Optical observations
  68. GRB 071013: optical observations at NOT
  69. GRB071010B, BVRcIc field calibration
  70. GRB 20071013: Xinglong TNT optical Upper Limit
  71. GRB 071010C Swift-BAT detection of a burst
  72. GRB 071011: Optical Limit after 13.95hrs
  73. GRB 071010B correction to GCN 6892 optical observations
  74. GRB 071011: Swift-XRT refined analysis
  75. VLA non-detection of GRB 071010A
  76. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  77. GRB 071011: Confirmation of P60 optical afterglow
  78. GRB 071010B: Optical Detection
  79. GRB 071011: Kanazawa Optical limits
  80. GRB 071011: P60 Optical Afterglow Candidate
  81. GRB 071011: MARGE Optical Limits
  82. GRB 071010B: Super-LOTIS upper limit
  83. GRB 071010B optical photometry
  84. GRB 071011: XRT afterglow detection
  85. GRB 071011: NAYUTA Optical Observation
  86. GRB 071010A: Continued Keck Imaging
  87. GRB 071010B: Bright OT confirmed with TLS
  88. Optical Observation: GRB 071010
  89. Optical observations: GRB 071010A
  90. GRB071010B: Swift/XRT detection
  91. GRB 071010A: Keck/LRIS Photometry
  92. GRB 071010 REM NIR observations
  93. GRB 071010: TAROT La Silla observatory detection of the afterglow
  94. Radio detection of GRB 071003 with the VLA
  95. GRB 070810B: further XRT analysis
  96. Konus-Wind observation of GRB 071003
  97. GRB 071003: Possible rebrightening
  98. GRB 071003 : Lulin R-band observations
  99. GRB 071003: OA power-law decay indices from KAIT
  100. GRB 071003: P60 Confirmation of Optical Afterglow

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