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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"

25904 results found.

  1. GRB021104: Candidate present in DSS
  2. GRB021104: possible optical afterglow
  3. GRB021004, late-time optical observations
  4. GRB021004: Optical Observations
  5. GRB 020813; likely host galaxy.
  6. GRB 021016, optical observations
  7. GRB021004: Optical Observations
  8. GRB021004: High-resolution optical spectroscopy
  9. GRB021004, UBVRcIc field photometry update
  10. GRB021004: Optical Observations
  11. GRB021004 Chandra HETG Observations
  12. GRB021004: optical observation
  13. GRB 021004: WC wind?
  14. GRB 021004: Optical observations, AUDE network
  15. GRB 021004 - VLA Radio Observations
  16. GRB 021004 - Unusual Radio-to-Submm Spectrum
  17. GRB021004: optical observations and predicted break time
  18. GRB021004: BVRc photometry
  19. GRB 021004 redshift
  20. GRB021004: restart of optical decay
  21. GRB 021004: Optical Decay
  22. GRB 021004, spectroscopic observations
  23. GRB021004: not fading anymore?
  24. GRB 021004: Optical Photometry at 2.5 Days
  25. GRB 021004: polarimetric observations
  26. GRB021004: Update Bisei photometric data
  27. GRB 021004: Optical Decay
  28. GRB021004, astrometric position
  29. GRB021004, Optical Observations
  30. IRAM Millimeter detection of GRB 021004
  31. GRB 021004: Optical observations at RIKEN
  32. GRB021004: continued fading
  33. GRB 021004: Optical Photometry at 1.5 Days
  34. GRB021004, Optical Observations
  35. GRB021004, BVRcIc field photometry
  36. GRB 021004: optical counterpart
  37. GRB 021004: Optical Observations
  38. GRB 021004, SPM optical observations
  39. GRB 021004, optical observations
  40. GRB 021004: radio observations
  41. GRB 021004: steepening of the optical decay slope
  42. GRB021004: optical observations at Nyrola
  43. GRB021004: Absorption redshift
  44. GRB 021004: Kyoto observation
  45. GRB021004: Optical Afterglow
  46. XRF 020903: Correction to GCN 1560
  47. Radio Observations of XRF 020903: The Missing Link
  48. XRF 020903: Supernova
  49. GRB 020305: HST/STIS observations
  50. XRF 020903: Optical observations
  51. GRB020813: High-resolution optical spectroscopy
  52. Second epoch K band imaging of GRB 020819
  53. GRB 020819: Optical observations
  54. K band observation of GRB 020819
  55. HETE 2275: Optical observations
  56. GRB020813: Fading X-ray Afterglow Observed with Chandra
  57. GRB 020813: addendum to GCN 1498
  58. GRB020813: optical observations at Bisei
  59. GRB020813: V-band decay slope
  60. Polarimetry of GRB020813: evidence for variability
  61. GRB020813 IRAM millimeter observations
  62. GRB020813(=H2262): Revised Localization with HETE SXC
  63. GRB020813: optical observations; possible host galaxy
  64. GRB 020813, radio detection
  65. GRB 020812 : optical afterglow candidate
  66. GRB020812: optical observations
  67. GRB020813, optical observations
  68. GRB020812: possible afterglow candidate
  69. GRB020812: possible afterglow candidate
  70. GRB020813, astrometric position
  71. Spectropolarimetry of GRB 020813
  72. GRB 020813 Afterglow Observations; Possible break
  73. GRB 020813: Absorption redshift
  74. GRB020813: optical afterglow
  75. GRB020813: Candidate Optical Afterglow
  76. GRB 020715, optical observations
  77. GRB 020714, optical observations
  78. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  79. HST Imaging of the Host of GRB 011121
  80. GRB020801, optical afterglow candidate
  81. GRB020331: Late-time Optical Light Curve (re-submission)
  82. GRB020331: Late-time Optical Light Curve
  83. GRB 020405: HST observations reveal red bump
  84. GRB 020410: Discovery of Probable OT by HST
  85. GRB 020124, HST observations of the fading afterglow
  86. GRB 020705: Optical observations
  87. GRB 020625: Optical observations
  88. GRB 020531: optical photometry of Chandra sources
  89. HETE #2081: Optical observations
  90. GRB/XRF 020427, detection of an underlying system with the VLT
  91. GRB 020531, simultaneous optical observations
  92. GRB 020604, optical observations
  93. GRB 020531/Candidate Redshift
  94. GRB 020418, optical/near-IR observations
  95. GRB020531: Upper Limit for Detection of Two TAROT Sources
  96. GRB 020603: Optical observations
  97. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  98. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  99. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  100. GRB020321 : Optical observations.

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