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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"

26042 results found.

  1. GRB 030131: afterglow candidate
  2. GRB 020819: afterglow candidate
  3. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  4. GRB030115 submm upper limit
  5. GRB 030115: Further IR observations with IRSF/SIRIUS
  6. GRB 030115: Radio detection of IR candidate
  7. GRB 030115: IR observations with IRSF/SIRIUS
  8. GRB030115: R-band counterpart of IR candidate
  9. GRB030115, afterglow candidate
  10. GRB 021211: R-band observations at late-time
  11. GRB 021211: VLT spectrum
  12. GRB 021211: Probable Host and Underlying Supernova
  13. GRB021211, radio observations
  14. GRB 021112: Evidence for Another Dark Optical Afterglow
  15. VLT spectra of GRB 021211 revisited
  16. GRB021211: APO optical observations
  17. GRB 021211, optical observations
  18. GRB 021211: CTIO observations
  19. GRB021211: Measurement of Early Time Afterglow
  20. VLT spectrum of GRB 021211
  21. GRB 021211: early break in light curve
  22. GRB021211: Optical observations in CrAO
  23. GRB 021211, IR observations
  24. GRB 021211, optical observations
  25. GRB021211: Kiso Observations
  26. GRB021204: Kiso Observations
  27. GRB021211: Optical observations
  28. GRB 021211, R- and I-band observations
  29. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  30. HETE 2493: Optical observations
  31. HETE 2493: Optical observations
  32. GRB021201, BVRcIc field photometry
  33. GRB 021112: Afterglow or Variable Star?
  34. GRB 021113: Evidence for a Dark Optical Afterglow
  35. GRB021112, BVRI field photometry
  36. GRB 021113: Optical observations
  37. GRB021004: Near infrared spectroscopy
  38. GRB021104: optical observations
  39. GRB021104: Candidate present in DSS
  40. GRB021104: possible optical afterglow
  41. GRB021004, late-time optical observations
  42. GRB021004: Optical Observations
  43. GRB 020813; likely host galaxy.
  44. GRB 021016, optical observations
  45. GRB021004: Optical Observations
  46. GRB021004: High-resolution optical spectroscopy
  47. GRB021004, UBVRcIc field photometry update
  48. GRB021004: Optical Observations
  49. GRB021004 Chandra HETG Observations
  50. GRB021004: optical observation
  51. GRB 021004: WC wind?
  52. GRB 021004: Optical observations, AUDE network
  53. GRB 021004 - VLA Radio Observations
  54. GRB 021004 - Unusual Radio-to-Submm Spectrum
  55. GRB021004: optical observations and predicted break time
  56. GRB021004: BVRc photometry
  57. GRB 021004 redshift
  58. GRB021004: restart of optical decay
  59. GRB 021004: Optical Decay
  60. GRB 021004, spectroscopic observations
  61. GRB021004: not fading anymore?
  62. GRB 021004: Optical Photometry at 2.5 Days
  63. GRB 021004: polarimetric observations
  64. GRB021004: Update Bisei photometric data
  65. GRB 021004: Optical Decay
  66. GRB021004, astrometric position
  67. GRB021004, Optical Observations
  68. IRAM Millimeter detection of GRB 021004
  69. GRB 021004: Optical observations at RIKEN
  70. GRB021004: continued fading
  71. GRB 021004: Optical Photometry at 1.5 Days
  72. GRB021004, Optical Observations
  73. GRB021004, BVRcIc field photometry
  74. GRB 021004: optical counterpart
  75. GRB 021004: Optical Observations
  76. GRB 021004, SPM optical observations
  77. GRB 021004, optical observations
  78. GRB 021004: radio observations
  79. GRB 021004: steepening of the optical decay slope
  80. GRB021004: optical observations at Nyrola
  81. GRB021004: Absorption redshift
  82. GRB 021004: Kyoto observation
  83. GRB021004: Optical Afterglow
  84. XRF 020903: Correction to GCN 1560
  85. Radio Observations of XRF 020903: The Missing Link
  86. XRF 020903: Supernova
  87. GRB 020305: HST/STIS observations
  88. XRF 020903: Optical observations
  89. GRB020813: High-resolution optical spectroscopy
  90. Second epoch K band imaging of GRB 020819
  91. GRB 020819: Optical observations
  92. K band observation of GRB 020819
  93. HETE 2275: Optical observations
  94. GRB020813: Fading X-ray Afterglow Observed with Chandra
  95. GRB 020813: addendum to GCN 1498
  96. GRB020813: optical observations at Bisei
  97. GRB020813: V-band decay slope
  98. Polarimetry of GRB020813: evidence for variability
  99. GRB020813 IRAM millimeter observations
  100. GRB020813(=H2262): Revised Localization with HETE SXC

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