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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"

28042 results found.

  1. GRB 021004: Host Galaxy Star Formation Rate
  2. GRB 021004 submm observations
  3. GRB 021004: WC wind?
  4. GRB021004: NIR and Optical observations
  5. GRB 021004: Optical observations, AUDE network
  6. GRB 021004 - VLA Radio Observations
  7. GRB 021004 - Unusual Radio-to-Submm Spectrum
  8. GRB 021004: optical spectroscopy
  9. IPN triangulation of GRB021007 (annulus)
  10. GRB021004: optical observations and predicted break time
  11. GRB021004: BVRc photometry
  12. GRB021004 radio observation
  13. HETE fluences for GRB021004
  14. GRB 021004: Optical Photometry at 2.5 Days
  15. GRB 021004: polarimetric observations
  16. GRB 021004: V-band Polarimetric Observations
  17. GRB021004: Update Bisei photometric data
  18. IRAM Millimeter detection of GRB 021004
  19. GRB 021004 radio observation
  20. GRB 021004: Optical Photometry at 1.5 Days
  21. GRB021004, BVRcIc field photometry
  22. GRB021004: Optical Spectroscopy
  23. GRB 021004 radio search
  24. XRF020903, BVRI field photometry
  25. XRF020903: TNG and Asiago photometry
  26. GRB 020903: Optical observations at RIKEN
  27. XRF 020903: Correction to GCN 1560
  28. XRF 020903: VRI observations
  29. XRF 020903: R band observations
  30. XRF 020903: Archival Optical Images
  31. Radio Observations of XRF 020903: The Missing Link
  32. XRF 020903: Supernova
  33. IPN triangulation of GRB020923 (two error boxes)
  34. IPN triangulation of GRB020914B
  35. IPN triangulation of GRB020911 (2 large error boxes)
  36. GRB 020305: HST/STIS observations
  37. Confirmation of IPN error box for GRB020910
  38. IPN triangulation of GRB020910
  39. IPN GCN Circulars now to be issued without restriction
  40. Single IPN error box for GRB020904
  41. XRF 020903: optical observation at Kyoto
  42. GRB020322 : HST/STIS observations
  43. XRF 020903: Optical observations
  44. IPN triangulation of GRB020904
  45. INTEGRAL GRBs added to GCN
  46. SGR1900+14 burst localized by HETE
  47. GRB020813: High-resolution optical spectroscopy
  48. GRB020812: negative optical observations
  49. GRB 020812: optical observation at Kyoto University
  50. Second epoch K band imaging of GRB 020819
  51. GRB 020813 : HST observations
  52. GRB 020812: early time optical observation at Ouda Station
  53. GRB020813: Magellan BVRI Photometry
  54. GRB 020819: Optical observations
  55. K band observation of GRB 020819
  56. GRB020813: optical and NIR observations
  57. GRB020813: Fading X-ray Afterglow Observed with Chandra
  58. GRB020813, UBVRI field calibration
  59. GRB020812: NIR observations
  60. Polarimetry of GRB020813: evidence for variability
  61. GRB020813 IRAM millimeter observations
  62. GRB020812: optical observations
  63. GRB020813: High-Resolution Optical Observations
  64. GRB 020812: optical observation at Bisei
  65. GRB020813: Early Time Magnitude
  66. Millimeter observation of GRB 020813
  67. GRB020812: optical observations
  68. GRB 020813 : KISO multiband optical observations
  69. GRB020813, optical observations
  70. IPN error box for GRB020813
  71. GRB020813, astrometric position
  72. Spectropolarimetry of GRB 020813
  73. GRB 020812 optical observation
  74. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  75. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  76. HST Imaging of the Host of GRB 011121
  77. GRB020801, optical afterglow candidate
  78. GRB020331: Late-time Optical Light Curve (re-submission)
  79. GRB020331: Late-time Optical Light Curve
  80. IPN triangulation of GRB020714
  81. IPN triangulation of GRB020715 (=GRB150702)
  82. IPN triangulation of GRB020714
  83. IPN triangulation of GRB150702
  84. GRB 020410: Discovery of Probable OT by HST
  85. GRB 020124, HST observations of the fading afterglow
  86. IPN triangulation of GRB020708
  87. IPN triangulation of GRB020708
  88. Correction to IPN error box for GRB020706
  89. IPN triangulation of GRB020706
  90. GRB 020705: Optical observations
  91. GRB 020625, optical observations
  92. GRB 020625: Optical observations
  93. GRB 020531: optical photometry of Chandra sources
  94. GRB020625 (=H2081): A Long Burst Localized by HETE
  95. The Probable Host Galaxy of GRB/XRF 020427
  96. GRB/XRF 020427, detection of an underlying system with the VLT
  97. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  98. AXP 1E2259+586 optical observations
  99. Fading Optical Source in the Field of GRB020531
  100. GRB 020531, INT+WFC deep optical upper limits

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