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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"

26507 results found.

  1. XRF 030723: Detection of the likely host galaxy
  2. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  3. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  4. IPN triangulation of GRB030921 (large error box)
  5. IPN triangulation of GRB030919 (large error box)
  6. GRB030913: Subaru Optical Observations
  7. GRB 030913: ROTSE-3c Optical Observations
  8. GRB 030913, optical candidate
  9. GRB030913: AAVSO optical observations
  10. GRB 030913, BOOTES observations
  11. GRB030913 (=H2849): TAROT Observations
  12. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  13. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  14. GRB 030913: Optical limit at RIKEN
  15. XRF030824: Optical observations
  16. IPN triangulation of GRB030903 (large error box)
  17. IBAS detection of bursts from SGR 1806-20
  18. IPN triangulation of GRB030827 (large error box)
  19. GRB 030823 observation at Ouda
  20. XRF030824: Second-epoch Palomar observations
  21. GRB030823: optical observations
  22. GRB030823: Palomar observations
  23. XRF030824: Palomar observations
  24. GRB030823: optical observation at Tokyo Tech
  25. RAPTOR observations of GRB030823
  26. Lulin follow-up observations of GRB030823
  27. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  28. 030813 SGR event (Konus-Wind observation)
  29. GRB 030817 = H2808 TAROT optical observations
  30. SGR 1808-20 (=H2802): A Possible new SGR
  31. GRB 021206 Optical Observations
  32. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  33. XRF030723, BVRcIc field photometry update
  34. IPN triangulation of GRB030801 (large error box)
  35. GRB021206 optical counterpart upper limit
  36. XRF030723: Re-analysis of ROTSE-III early images
  37. XRF030723 (=H2777): Second Epoch Magellan Observations
  38. GRB 030725: optical observations.
  39. IPN triangulation of GRB030726 (large error box)
  40. IPN triangulation of GRB030721 (large error box)
  41. XRF030723 Radio Observations
  42. XRF 030723: confirmation of fading optical counterpart
  43. XRF030723(=H2777): Chandra Observations
  44. GRB030723: Upper limits from historical observations
  45. XRF030723: Palomar observations and proposed counterpart
  46. GRB030725 (=H2779): A Bright GRB Localized by HETE
  47. XRF030723: optical observations
  48. XRF030723, BVRcIc field photometry correction
  49. XRF030723, ROTSE-III Early Observations
  50. XRF030723, BVRcIc field photometry
  51. XRF 030723, optical observations
  52. XRF 030723, optical observations
  53. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  54. Konus-Wind detection of the bursts from SGR1806-20 region
  55. SGR 1806-20, submm observations
  56. RXTE PCA Observations of SGR1806-20 Region
  57. IPN triangulation of GRB030714 (two large error boxes)
  58. IPN triangulation of GRB030715 (two large error boxes)
  59. GRBlog: Compilation of all GCN Circ. data
  60. GRB030706 triangulation (single large error box)
  61. GRB030329, optical observation in May
  62. IPN triangulation of GRB030626 (single large error box)
  63. IPN triangulation of GRB030626 (two large error boxes)
  64. GRB030329: second XMM-Newton observation
  65. GRB030418: R optical observations
  66. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  67. IPN triangulation of GRB030606 (two alternate error boxes)
  68. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  69. GRB 030528: tentative NIR counterpart
  70. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  71. GRB030329, further radio observations at GMRT
  72. GRB030528, BVRI field photometry
  73. GRB030329, SPM optical observations
  74. GRB030528(=H2724): Revised SXC Localization
  75. GRB 030528 Bisei optical observation
  76. GRB030528 (H2724): A long GRB localized by HETE
  77. GRB 030329: Correction to GCN 2254
  78. GRB 030329: Optical Observations
  79. GRB 030528 (=H2724) Kyoto optical observation
  80. GRB030329, Optical observations
  81. GRB 030329: HST ACS Observations of the Host
  82. GRB 030329 Optical Observations
  83. GRB030329: XMM-Newton observation
  84. GRB 021004: HST observations
  85. GRB030324: Further Observations of the Candidate Optical Afterglow
  86. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  87. IPN triangulation of GRB030519B=H2716 (small error box)
  88. HETE GRB030329, correction to Rc Observations in Loiano
  89. GRB 030329: Optical limit (contemporaneous imaging)
  90. IPN triangulation of GRB030509 (small errror box)
  91. IPN triangulation of GRB030509 - correction
  92. GRB030429, refiend optical brightness
  93. GRB030418, BVRcIc field photometry
  94. GRB030429, BVRcIc field photometry
  95. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  96. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  97. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  98. GRB030429: RTT150 optical observations, a possible host galaxy
  99. GRB030329: RTT150 optical observations and upper limit for a host
  100. GRB030501 triangulation (correction to GCN 2194)

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