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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"

16161 results found.

  1. GRB 021113: Optical Observations
  2. GRB021113 (=H2449): A Long GRB Localized by HETE
  3. GRB 021112: Optical Observations
  4. GRB021112 (=H2448): A Long GRB Localized by HETE
  5. GRB 021016: Optical Observations
  6. GRB021104: Optical Observations
  7. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  8. GRB021104: Optical observations
  9. GRB021104: optical observations
  10. GRB021104: Candidate present in DSS
  11. GRB021104: possible optical afterglow
  12. GRB021004, late-time optical observations
  13. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  14. GRB 021004: optical observations
  15. GRB021004: Optical Observations
  16. GRB 020813; likely host galaxy.
  17. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  18. GRB 021016, optical observations
  19. GRB 021004: VRI observations at TNG: possible break
  20. GRB021016, optical observations
  21. GRB 021008, optical observations
  22. GRB021016(=H2397): A Long GRB Localized by HETE
  23. GRB021004: Optical Observations
  24. GRB 021004: optical spectroscopy on Oct 11
  25. GRB021004: High-resolution optical spectroscopy
  26. XRF 020903: flattening of the optical light curve.
  27. GRB021004: Optical Observations
  28. GRB021004 Chandra HETG Observations
  29. GRB 021004: Optical/NIR Observations
  30. GRB 021004: Additional V-band Polarimetric Observations
  31. GRB021004: optical observation
  32. GRB 021004: WC wind?
  33. GRB021004: NIR and Optical observations
  34. GRB 021004: Optical measurement at OHP
  35. GRB 021004: Optical observations, AUDE network
  36. GRB 021004 - Unusual Radio-to-Submm Spectrum
  37. GRB 021004: optical spectroscopy
  38. XRF 020903 spectrum
  39. GRB021004: optical observations and predicted break time
  40. GRB 021004 redshift
  41. GRB021004: restart of optical decay
  42. GRB 021004: Optical Decay
  43. GRB 021004 continued IR fading
  44. HETE fluences for GRB021004
  45. GRB 021004: Optical Photometry at 2.5 Days
  46. GRB 021004: V-band Polarimetric Observations
  47. GRB 021004: Optical Decay
  48. GRB021004, astrometric position
  49. GRB021004, Optical Observations
  50. GRB 021004: Optical observations at RIKEN
  51. GRB 021004: Optical Observations
  52. GRB021004: continued fading
  53. GRB 021004: Optical Photometry at 1.5 Days
  54. GRB021004, Optical Observations
  55. GRB 021004: Optical observations
  56. GRB 021004: optical counterpart
  57. GRB 021004, optical observations
  58. GRB021004: Optical Spectroscopy
  59. GRB 021004: Optical Observations
  60. GRB 021004, SPM optical observations
  61. GRB 021004, optical observations
  62. GRB 021004: radio observations
  63. GRB 021004: steepening of the optical decay slope
  64. GRB021004: Upper limits from recent and historical observations
  65. GRB021004: optical observations at Nyrola
  66. GRB021004: Absorption redshift
  67. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  68. GRB021004: optical observations at Bisei
  69. GRB 021004: Kyoto observation
  70. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  71. GRB021004: Optical Afterglow
  72. GRB 020903: Optical observations at RIKEN
  73. XRF 020903: Archival Optical Images
  74. Radio Observations of XRF 020903: The Missing Link
  75. XRF 020903: Supernova
  76. GRB 020305: HST/STIS observations
  77. XRF 020903: optical observation at Kyoto
  78. GRB020322 : HST/STIS observations
  79. XRF 020903: Optical observations
  80. XRF 020903: Optical observations
  81. XRF 020903, optical observations
  82. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  83. GRB020813: optical observation
  84. GRB020812: optical observation
  85. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  86. SGR1900+14 burst localized by HETE
  87. GRB020813: High-resolution optical spectroscopy
  88. GRB020819: optical observations at Bisei
  89. GRB020812: negative optical observations
  90. GRB 020812: optical observation at Kyoto University
  91. GRB 020813 : HST observations
  92. GRB020819 : Optical observations at KISO
  93. GRB 020812: early time optical observation at Ouda Station
  94. GRB020813: VRI Decay Slopes
  95. GRB 020819: Optical observations
  96. GRB020819: optical observations
  97. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  98. HETE 2275: Optical observations
  99. GRB020813: optical and NIR observations
  100. GRB020813: Fading X-ray Afterglow Observed with Chandra

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