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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"

21793 results found.

  1. VLT spectroscopy of the probable host of GRB 021211
  2. GRB 021211: Probable Host and Underlying Supernova
  3. GRB021211, radio observations
  4. GRB 021219: OSN optical observations
  5. GRB021219: Radio Observations
  6. GRB021219, optical observations
  7. IPN triangulation of GRB021219
  8. VLT spectra of GRB 021211 revisited
  9. GRB021211: APO optical observations
  10. XRF 020903 : HST observations
  11. GRB 021201: Optical Observations
  12. GRB 021211, optical observations
  13. GRB 021211: CTIO observations
  14. VLT spectrum of GRB 021211
  15. GRB 021211: early break in light curve
  16. GRB021211: Optical observations in CrAO
  17. GRB 021211, IR observations
  18. GRB 021211, optical observations
  19. GRB 021211: Optical Observations
  20. GRB021211: Kiso Observations
  21. GRB021204: Kiso Observations
  22. GRB 021201, optical observations
  23. GRB 021211: Radio Observations
  24. GRB021211: Optical observations
  25. GRB 021201 (short/hard), NOT observations
  26. SUB-MM SEARCH FOR GRB 021211
  27. GRB 021211 Milagro GeV/TeV Observations
  28. GRB 021211, R- and I-band observations
  29. GRB021211 - Upper limits from recent and historical observations
  30. GRB021211, OT at 108 s
  31. GRB 021204: I-band Observations
  32. HETE 2493: Optical observations
  33. HETE 2493: Optical observations
  34. HETE 2493: Optical candidate
  35. GRB 021204: Optical Observations at RIKEN
  36. GRB 021125: Radio Observations
  37. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  38. GRB 021201, Radio Observations
  39. GRB 021201: Optical Observations
  40. GRB 021201: BOOTES simultaneous optical observations
  41. GRB021004, late time optical observations
  42. GRB 021112: Afterglow or Variable Star?
  43. GRB021113: optical observations at Bisei
  44. GRB 021113: Evidence for a Dark Optical Afterglow
  45. GRB 021112, Radio Observations
  46. GRB 021112: Variable Source in R-band search
  47. GRB021112: Optical Observations
  48. GRB021113: Kiso Observations
  49. GRB 021113: Optical observations
  50. GRB 021112: RAPTOR Observations
  51. GRB 021113: Optical Observations
  52. GRB 021113: Optical Observations
  53. GRB 021112: Optical Observations
  54. GRB 021112: R-band search
  55. GRB 021016: Optical Observations
  56. GRB021004: Near infrared spectroscopy
  57. GRB021104: Optical Observations
  58. GRB021104: Optical observations
  59. GRB021104: optical observations
  60. Detection of activity from SGR 1900+14 with the RXTE/PCA
  61. GRB021004, late-time optical observations
  62. GRB 021004: optical observations
  63. GRB021004: Optical Observations
  64. GRB 020813; likely host galaxy.
  65. GRB 021008, radio observations
  66. GRB 021016, optical observations
  67. GRB 021004: VRI observations at TNG: possible break
  68. GRB021016, optical observations
  69. GRB 021008, optical observations
  70. GRB021004: Optical Observations
  71. GRB 021004: optical spectroscopy on Oct 11
  72. GRB021004: High-resolution optical spectroscopy
  73. XRF 020903: flattening of the optical light curve.
  74. GRB021004: Optical Observations
  75. GRB 021004 submm observations
  76. GRB021004 Chandra HETG Observations
  77. GRB 021004: Optical/NIR Observations
  78. GRB 021004: Additional V-band Polarimetric Observations
  79. GRB 021004: Host Galaxy Star Formation Rate
  80. GRB 021004 submm observations
  81. GRB 021004: WC wind?
  82. GRB021004: NIR and Optical observations
  83. GRB 021004: Optical observations, AUDE network
  84. GRB 021004 - VLA Radio Observations
  85. GRB 021004 - Unusual Radio-to-Submm Spectrum
  86. GRB 021004: optical spectroscopy
  87. XRF 020903 spectrum
  88. GRB 021004: HST/STIS spectroscopic observations
  89. GRB021004: optical observations and predicted break time
  90. GRB021004: BVRc photometry
  91. GRB 021004 redshift
  92. GRB 021004 continued IR fading
  93. GRB 021004, spectroscopic observations
  94. GRB021004: not fading anymore?
  95. GRB 021004: Optical Photometry at 2.5 Days
  96. GRB 021004: polarimetric observations
  97. GRB 021004: V-band Polarimetric Observations
  98. GRB021004: Update Bisei photometric data
  99. GRB021004, Optical Observations
  100. GRB 021004: Optical observations at RIKEN

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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