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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"

32494 results found.

  1. GRB 021211, optical observations
  2. GRB 021211: CTIO observations
  3. GRB021211: Measurement of Early Time Afterglow
  4. VLT spectrum of GRB 021211
  5. GRB 021211: early break in light curve
  6. GRB021211, BVRI field photometry
  7. GRB021211: Optical observations in CrAO
  8. GRB 021211, IR observations
  9. GRB 021211, optical observations
  10. GRB 021211: Optical Observations
  11. GRB021211: Kiso Observations
  12. GRB 021201, optical observations
  13. GRB 021211: Radio Observations
  14. GRB021211: Optical observations
  15. GRB 021201 (short/hard), NOT observations
  16. SUB-MM SEARCH FOR GRB 021211
  17. Chandra observation of the IPN error box of GRB021201 (short/hard)
  18. GRB 021211, R- and I-band observations
  19. GRB021211 - Upper limits from recent and historical observations
  20. GRB021211, OT at 108 s
  21. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  22. HETE 2493: Optical observations
  23. GRB 021125: Radio Observations
  24. IPN triangulation of GRB021206 (small error box)
  25. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  26. GRB021201, BVRcIc field photometry
  27. GRB 021201, Radio Observations
  28. GRB 021201: Optical Observations
  29. GRB 021201: BOOTES simultaneous optical observations
  30. GRB021004, late time optical observations
  31. GRB021004 Chandra Observation
  32. GRB021125 refined position
  33. IPN triangulation of GRB021125B (two large error boxes)
  34. IPN triangulation of GRB021119 (large error box)
  35. Improved IPN error box for GRB021125
  36. IPN BURST POSITION
  37. IPN confirmation of the reactivation of SGR1900+14
  38. GRB021113, SPI ACS observation
  39. GRB 021112: Afterglow or Variable Star?
  40. GRB021113: optical observations at Bisei
  41. GRB 021113: Evidence for a Dark Optical Afterglow
  42. GRB 021112: Variable Source in R-band search
  43. GRB021112: Optical Observations
  44. IPN triangulation of GRB021109 (portion of annulus)
  45. IPN triangulation of GRB021113 (=H2449; annulus)
  46. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  47. GRB 021113: Optical Observations
  48. GRB 021113: Optical Observations
  49. GRB021113 (=H2449): A Long GRB Localized by HETE
  50. GRB 021112: Optical Observations
  51. GRB 021112: R-band search
  52. IPN triangulation of GRB021108 (large error box)
  53. GRB021112 (=H2448): A Long GRB Localized by HETE
  54. GRB 021016: Optical Observations
  55. GRB021004: Near infrared spectroscopy
  56. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  57. Spectropolarimetry of GRB021004
  58. GRB021104: optical observations
  59. GRB021104: Candidate present in DSS
  60. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  61. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  62. IPN triangulation of GRB021025 (portion of annulus)
  63. IPN triangulation of GRB021027 (single large error box)
  64. GRB021004, late-time optical observations
  65. IPN triangulation of GRB021027 (two large error boxes)
  66. GRB 021023: Infrared Imaging
  67. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  68. IPN triangulation of SGR1900+14, October 22 2002
  69. GRB 021004: optical observations
  70. GRB021004: Optical Observations
  71. GRB 020813; likely host galaxy.
  72. IPN triangulation of GRB021020 (smaller error box)
  73. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  74. GRB 021008, radio observations
  75. GRB 021016, optical observations
  76. GRB 021004: VRI observations at TNG: possible break
  77. GRB021016, optical observations
  78. GRB 021008, optical observations
  79. GRB021016(=H2397): A Long GRB Localized by HETE
  80. IPN triangulation of GRB021016 (area corrected)
  81. IPN triangulation of GRB021016 (small error box)
  82. GRB021004: Optical Observations
  83. IPN triangulation of GRB021013 (single error box)
  84. GRB 021004: optical spectroscopy on Oct 11
  85. IPN triangulation of GRB021013 (two small error boxes)
  86. GRB021004: High-resolution optical spectroscopy
  87. XRF 020903: flattening of the optical light curve.
  88. GRB021004, UBVRcIc field photometry update
  89. IPN triangulation of GRB021008 (single error box)
  90. GRB021004: Optical Observations
  91. GRB 021004 submm observations
  92. IPN triangulation of GRB021008 (two small error boxes)
  93. GRB 021004: Optical/NIR Observations
  94. GRB 021004: Additional V-band Polarimetric Observations
  95. GRB021004: optical observation
  96. GRB 021004: Host Galaxy Star Formation Rate
  97. GRB 021004 submm observations
  98. GRB 021004: WC wind?
  99. GRB021004: NIR and Optical observations
  100. GRB 021004: Optical measurement at OHP

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