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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"

26040 results found.

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

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