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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"

26040 results found.

  1. GRB 020812 : optical afterglow candidate
  2. GRB020812: optical observations
  3. GRB020813, optical observations
  4. GRB020812: possible afterglow candidate
  5. GRB020812: possible afterglow candidate
  6. GRB020813, astrometric position
  7. Spectropolarimetry of GRB 020813
  8. GRB 020813 Afterglow Observations; Possible break
  9. GRB 020813: Absorption redshift
  10. GRB020813: optical afterglow
  11. GRB020813: Candidate Optical Afterglow
  12. GRB 020715, optical observations
  13. GRB 020714, optical observations
  14. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  15. HST Imaging of the Host of GRB 011121
  16. GRB020801, optical afterglow candidate
  17. GRB020331: Late-time Optical Light Curve (re-submission)
  18. GRB020331: Late-time Optical Light Curve
  19. GRB 020405: HST observations reveal red bump
  20. GRB 020410: Discovery of Probable OT by HST
  21. GRB 020124, HST observations of the fading afterglow
  22. GRB 020705: Optical observations
  23. GRB 020625: Optical observations
  24. GRB 020531: optical photometry of Chandra sources
  25. HETE #2081: Optical observations
  26. GRB/XRF 020427, detection of an underlying system with the VLT
  27. GRB 020531, simultaneous optical observations
  28. GRB 020604, optical observations
  29. GRB 020531/Candidate Redshift
  30. GRB 020418, optical/near-IR observations
  31. GRB020531: Upper Limit for Detection of Two TAROT Sources
  32. GRB 020603: Optical observations
  33. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  34. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  35. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  36. GRB020321 : Optical observations.
  37. GRB020331: Third Epoch and Revised Second Epoch Optical
  38. GRB 020418: Optical observations
  39. GRB 020124: Optical observations
  40. GRB 020418: Optical observations
  41. GRB020410: BeppoSAX NFI observations refined analysis
  42. GRB020405: predicted break
  43. GRB 020409: Optical observations
  44. GRB 020409: No Evidence for an Optical Afterglow
  45. GRB 020409, 2nd epoch optical observations
  46. GRB 020331 Kyoto observation on March 31
  47. GRB 020409
  48. GRB020406(?), optical observations
  49. X-ray afterglow of GRB020321
  50. GRB020331: Confirmation of Afterglow Candidate with Magellan
  51. GRB 020405: Moderate-resolution spectroscopy
  52. GRB020331: Optical Observations of Afterglow Candidate
  53. Revised Photometry of the Optical Afterglow of GRB 020405
  54. GRB 020331: Candidate Optical Afterglow
  55. GRB 020405: Decay index
  56. GRB020405, Radio Observations
  57. GRB020405: VLT spectroscopy
  58. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  59. GRB 020405: Optical afterglow candidate
  60. GRB 020331: NIR Observations
  61. GRB 020331: NIR Observations
  62. GRB020331 NIR observation at KPNO (re-submission)
  63. GRB02033 NIR observation at KPNO
  64. GRB020331 field photometry
  65. GRB 020331, NIR observations
  66. GRB 020331: Optical observations
  67. GRB 020322: BeppoSAX observations of the X-ray afterglow
  68. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  69. GRB 020322, Radio observations
  70. Near-Infrared Observations of GRB020322 at TIRGO
  71. GRB 020321, Radio Observations
  72. GRB 020322: Optical Observations
  73. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  74. GRB 020321: Optical observations
  75. GRB020317 BVRI field photometry
  76. GRB 020322 optical observations
  77. GRB020322: Candidate Optical Afterglow
  78. GRB020322, optical observations
  79. GRB 020322: Optical candidate
  80. GRB 020321: Optical observations
  81. GRB 011121: Fourth Epoch of HST Imaging
  82. GRB020305: NIR observations
  83. GRB 020305: Optical Observations
  84. GRB 020317: Optical observations
  85. GRB 011121: Third HST Epoch
  86. GRB020305: Properties of the Candidate Optical Afterglow
  87. GRB 011121: HST Observations reveal an intermediate-time multicolor
  88. GRB011121, possible supernova association
  89. GRB020305: Subaru Optical Observations
  90. GRB 020305: Optical observations
  91. GRB 020305: Candidate optical afterglow
  92. HST Imaging of the afterglow and host of GRB 011121
  93. GRB 010921: HST Observations
  94. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  95. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  96. GRB 020124 Optical Observations
  97. GRB 020124: Optical afterglow
  98. GRB 011211: Detection of the Probable Host Galaxy
  99. Color indices of the afterglow of GRB011211
  100. GRB011212: Optical observations at Gunma

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