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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"

32495 results found.

  1. Swift XRT follow-up observations of GRB071008
  2. Swift/UVOT upper limits for GRB 071117
  3. GRB071118: Swift XRT refined analysis
  4. GRB 071117: Gemini Optical Afterglow Discovery
  5. GRB 071118, Swift-BAT refined analysis
  6. GRB 071112B: Gemini Image Differencing
  7. GRB 071117: Gemini Observations
  8. GRB 071117: Swift-XRT refined analysis
  9. GRB 071117, Swift-BAT refined analysis
  10. VLT FORS2 observations of short hard GRB071112B
  11. GRB 071117: Swift/XRT position
  12. VLA radio upper limit on GRB 071112C
  13. ATCA radio observations of short hard burst GRB 071112B
  14. GRB 071112C: Optical and NIR data observed with KANATA
  15. Correction to the Swift-BAT Transient Identification (trigger=296683)
  16. GRB 071112C: WSRT Radio Observations
  17. GRB071112C: Errata of MITSuME Ic band photometry
  18. GRB 071112C: optical observation
  19. GRB 071112C: optical observation
  20. GRB 071112C: emission lines and refined VLT redshift
  21. GRB 071112C MITSuME Akeno early optical observation
  22. GRB 071112C: Gemini Absorption Redshift
  23. GRB 071112B: 2nd epoch of Magellan i-band imaging
  24. GRB 071112C: SARA upper limit
  25. GRB 071112C : Second Epoch Lulin R-band observations
  26. GRB071112C MITSuME Okayama Optical Observation
  27. GRB 071112C: Swift-BAT refined analysis
  28. GRB 071112C: Swift/UVOT observations
  29. GRB 071112C: Swift XRT refined analysis
  30. GRB 071112C: Optical observations at Crni Vrh
  31. Swift UVOT upper limits of GRB071112B
  32. GRB 071112C: VLT redshift
  33. GRB 071112B: Magellan i-band imaging
  34. GRB 071112B: Gemini Optical Imaging (Correction)
  35. GRB 071112B: Gemini Optical Imaging
  36. GRB 071112B: Swift-XRT preliminary analysis
  37. GRB 071112B, Swift-BAT partial refined analysis of the SHB
  38. GRB071112C: NOT observations
  39. GRB 071112C: Palomar Pre-Imaging
  40. Swift-BAT trigger 296491 is not a GRB
  41. GRB 071112C : Lulin R-band observation
  42. GRB 071112C: RTT150 optical observations
  43. Swift XRT follow-up observations of GRB071028B
  44. GRB071112C Xinglong_TNT_and_EST_afterglow observations
  45. GRB 071112C: Optical and NIR afterglows observed with KANATA
  46. GRB 071112C: ROTSE-III Confirmation of Optical Counterpart
  47. GRB 071112B: ROTSE-III Rapid Optical Limits
  48. GRB071109: Super-LOTIS observations
  49. VLA IInd observation of INTEGRAL burst GRB 071109
  50. Swift/UVOT initial analysis of GRB071109
  51. GRB 071109: further Swift-XRT analysis
  52. No radio detection at Swift-XRT position
  53. GRB 071109: Swift-XRT possible X-ray counterpart
  54. VLA prompt radio detection of the INTEGRAL burst 071109
  55. GRB 071109: IBIS refined analysis
  56. GRB 071109: BOOTES-2 prompt optical observations
  57. GRB 071104: Swift-XRT Team Refined Analysis
  58. GRB 071104: Possible Swift UVOT Afterglow Candidate
  59. GRB 071104: Swift-XRT position
  60. GRB071010b: optical observation
  61. Swift XRT and UVOT observations of GRB071028B
  62. GRB 071101, Swift-BAT refined analysis
  63. GRB 071101: Swift-XRT Team refined analysis
  64. GRB071101: Optical and NIR upper limits by KANATA
  65. GRB0711101: Two new source from Xinglong TNT observation
  66. GRB 071101: TAROT Calern observatory optical observations
  67. GRB 071101: Swift XRT position
  68. GRB 071101: BOOTES-2 prompt optical observations
  69. GRB 071101: a nearby galaxy
  70. GRB 071031, Swift-BAT refined analysis
  71. GRB 071031: Swift/UVOT detection of afterglow
  72. GRB 071031: Swift-XRT Team refined analysis
  73. GRB 071020: MITSuME Akeno optical observations
  74. GRB 071031: REM NIR and Optical observation
  75. GRB 071031, SMARTS afterglow observations
  76. GRB 071031: VLT high-resolution spectroscopy
  77. GRB071031: Rapid PROMPT Detections
  78. GRB 071028B Swift-BAT detection of a burst
  79. GRB071025: Optical+NIR observations
  80. GRB 071028: SARA observations of variable source
  81. Swift UVOT upper limits to GRB071028
  82. GRB 071028: Swift-XRT Team refined analysis
  83. GRB 071028, Swift-BAT refined analysis
  84. GRB 071025: Kuiper Telescope Optical Observations
  85. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  86. GRB 071018: Revised BAT position
  87. GRB 071025A: RAPTOR Observations of Complex Early Optical Behavior
  88. GRB071021: MARGE Optical Limits
  89. GRB071020, optical upper limit
  90. GRB 071025: SARA VRI upper limits
  91. GRB 071025 Milagro GeV/TeV Observations
  92. GRB071025: Optical Pre-imaging from Palomar
  93. Swift UVOT upper limits
  94. GRB071025: Xinglong TNT I-band upper limit
  95. GRB 071025: Swift-XRT Team refined analysis
  96. GRB 071025, Swift-BAT refined analysis
  97. GRB 071025: Early Super-LOTIS Observations
  98. GRB 071025: R/I-band update
  99. GRB071021 : CFHT Ks-band observation
  100. GRB 071025: ROTSE-III Refined Analysis

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