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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"

20966 results found.

  1. XRF 020903: flattening of the optical light curve.
  2. GRB021004: Optical Observations
  3. GRB 021004 submm observations
  4. GRB021004 Chandra HETG Observations
  5. GRB 021004: Optical/NIR Observations
  6. GRB 021004: Additional V-band Polarimetric Observations
  7. GRB 021004 submm observations
  8. GRB 021004: WC wind?
  9. GRB021004: NIR and Optical observations
  10. GRB 021004: Optical observations, AUDE network
  11. GRB 021004 - VLA Radio Observations
  12. GRB 021004 - Unusual Radio-to-Submm Spectrum
  13. GRB 021004: optical spectroscopy
  14. GRB 021004: HST/STIS spectroscopic observations
  15. GRB021004: optical observations and predicted break time
  16. GRB021004: BVRc photometry
  17. GRB 021004: Optical Decay
  18. GRB 021004 continued IR fading
  19. GRB 021004, spectroscopic observations
  20. GRB 021004: polarimetric observations
  21. GRB 021004: V-band Polarimetric Observations
  22. GRB021004: Update Bisei photometric data
  23. GRB 021004: Optical Decay
  24. GRB021004, Optical Observations
  25. GRB 021004: Optical observations at RIKEN
  26. GRB 021004: Optical Observations
  27. GRB021004: continued fading
  28. GRB 021004: Optical Photometry at 1.5 Days
  29. GRB021004, Optical Observations
  30. GRB 021004: Optical observations
  31. GRB 021004, optical observations
  32. GRB021004: Optical Spectroscopy
  33. GRB 021004: Optical Observations
  34. GRB 021004, SPM optical observations
  35. GRB 021004, optical observations
  36. GRB 021004: radio observations
  37. GRB 021004: steepening of the optical decay slope
  38. GRB021004: Upper limits from recent and historical observations
  39. GRB021004: optical observations at Nyrola
  40. GRB021004: optical observations at Bisei
  41. GRB021004: Optical Afterglow
  42. XRF020903: TNG and Asiago photometry
  43. GRB 020903: Optical observations at RIKEN
  44. XRF 020903: Correction to GCN 1560
  45. XRF 020903: VRI observations
  46. GRB 020903: correction to GCN 1557
  47. XRF 020903: R band observations
  48. XRF 020903: Archival Optical Images
  49. Radio Observations of XRF 020903: The Missing Link
  50. XRF 020903: Supernova
  51. GRB 020305: HST/STIS observations
  52. GRB020322 : HST/STIS observations
  53. XRF 020903: Optical observations
  54. XRF 020903: Optical observations
  55. XRF 020903, optical observations
  56. GRB020813: High-resolution optical spectroscopy
  57. GRB020819: optical observations at Bisei
  58. GRB020812: negative optical observations
  59. GRB020813, Baade 6.5m data now available
  60. GRB 020813 : HST observations
  61. Confirming no variability for GRB02081
  62. GRB020819 : Optical observations at KISO
  63. GRB020813: VRI Decay Slopes
  64. GRB020813: Magellan BVRI Photometry
  65. GRB 020819: Optical observations
  66. K band observation of GRB 020819
  67. GRB020819: optical observations
  68. HETE 2275: Optical observations
  69. GRB020813: optical and NIR observations
  70. GRB020813: Fading X-ray Afterglow Observed with Chandra
  71. GRB020813: optical observations at Bisei
  72. GRB020812: NIR observations
  73. Polarimetry of GRB020813: evidence for variability
  74. GRB020813 IRAM millimeter observations
  75. GRB020812: optical observations
  76. GRB020813: High-Resolution Optical Observations
  77. GRB 020812: optical observation at Bisei
  78. GRB020813: optical observations; possible host galaxy
  79. GRB 020813, radio detection
  80. GRB 020812 : optical afterglow candidate
  81. GRB020813, optical observations
  82. Millimeter observation of GRB 020813
  83. GRB020812: optical observations
  84. GRB 020813 : KISO multiband optical observations
  85. GRB020813, optical observations
  86. GRB 020813 Afterglow Observations; Possible break
  87. GRB 020813 multiband optical observations
  88. GRB020813: Fading of Candidate OT
  89. GRB 020715, optical observations
  90. GRB 020714, optical observations
  91. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  92. GRB020801: Candidate OT present in DSS
  93. GRB020801, optical afterglow candidate
  94. GRB020331: Late-time Optical Light Curve (re-submission)
  95. GRB020331: Late-time Optical Light Curve
  96. GRB 020405: HST observations reveal red bump
  97. GRB 020410: Discovery of Probable OT by HST
  98. GRB 020124, HST observations of the fading afterglow
  99. GRB 020705: Optical observations
  100. GRB 020625, optical observations

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