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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"

20431 results found.

  1. GRB 120811C: optical observations
  2. GRB 120819A: MASTER final limits
  3. GRB 120819A: Bassano Bresciano Observatory optical observations
  4. GRB 120819A: GROND afterglow confirmation
  5. GRB 120819A: afterglow candidate from NOT
  6. GRB 120819A: MASTER optical observations
  7. GRB 120817B: Swift-XRT observations
  8. GRB 120811C: optical observations
  9. GRB 120815A: MASTER-ICATE observations
  10. GRB 120817B: LCO Optical Observations
  11. GRB 120815A: Swift/UVOT Detection of the Optical Afterglow
  12. GRB 120816A: Bassano Bresciano Observatory optical observations
  13. GRB 120817A: FTN and FTS observations
  14. GRB 120817A: Swift-XRT observations
  15. GRB 120816A: BOOTES-2 observations
  16. GRB120816A: OPTIMA discovery of optical counterpart
  17. GRB 120816A: TAROT Calern observatory optical observations
  18. GRB 120815A: GROND afterglow candidate
  19. GRB 120815A: Swift-XRT observations
  20. GRB 120815A: TAROT La Silla observatory optical observations
  21. GRB 120804A: Possible temporal break in the X-ray light-curve
  22. GRB 120811A: Swift/XRT-UVOT Obseravations
  23. GRB120804A: Chandra observations and afterglow detection
  24. GRB 120805A: optical afterglow confirmation from the NOT
  25. GRB 120811C: EVLA Observations
  26. GRB 120811C: RTT150 optical observations
  27. GRB 120811C: MASTER-Tunka OT observations
  28. GRB 120811C: NOT redshift
  29. GRB 120811C: Bassano Bresciano Observatory optical observations
  30. GRB 120811C: Swift/UVOT Detection
  31. GRB 120811C: RTT150 optical observations
  32. GRB 120811C: TAROT Calern observatory optical observations
  33. GRB 120811C: MASTER-Amur observations of fading OT
  34. GRB 120807A: Swift/UVOT Upper Limits
  35. GRB 120714B: GROND/FORS2 detection of a supernova
  36. GRB 120804A: ATCA 34GHz upper limit
  37. GRB 120802A: optical observations
  38. GRB 120804A: Gemini-North detection of an optical afterglow and putative host galaxy
  39. GRB 120807A: TAROT La Silla observatory optical observations
  40. GRB 120804A: ATCA 34GHz upper limit
  41. GRB 120805A: Swift/UVOT Upper Limits
  42. GRB 120802A: Swift/UVOT Upper Limits
  43. GRB 120805A: 1.23m CAHA observations
  44. GRB120805A: Liverpool Telescope observations
  45. GRB 120805A: TAROT Calern observatory optical observations
  46. GRB 120804A: EVLA Detection
  47. GRB 120804A: Gemini-North observations
  48. GRB 120804A: Swift/UVOT Upper Limits
  49. GRB 120804A: GROND upper limits
  50. GRB 120802A: EVLA Observations
  51. GRB 120803A: Swift-XRT Observations
  52. GRB 120802A Gemini-N redshift
  53. GRB 120802A: APEX/LABOCA submm observations
  54. GRB 120802A: MASTER optical observations
  55. GRB 120802A: optical uper limit in ISON-NM observatory
  56. GRB 120729A: JCMT SCUBA-2 sub-mm observation
  57. GRB 120729A: break in the optical light curve
  58. GRB 120729A: Optical observations from OSN, BOOTES1/2 and IAC80
  59. GRB 120729A: RTT150 optical observations
  60. GRB 120729A: EVLA Observations
  61. Virtual Telescope observations of GRB 120729A
  62. GRB 120729A: Early RAPTOR Observations
  63. GRB 120729A: UKIRT Observation
  64. T100 observations of GRB 120729A
  65. GRB 120728A: GROND Afterglow discovery
  66. GRB 120729A: Swift/UVOT Detection
  67. GRB 120729A: Xinglong TNT optical upper limit
  68. GRB 120728A: Swift/UVOT Upper Limits
  69. GRB 120729A Gemini-N redshift
  70. GRB120729A - Faulkes Telescope North Optical Afterglow Candidate
  71. GRB 120728A: GROND observations
  72. GRB 120727A/Galactic source: Fermi-LAT detection of a transient source
  73. GRB 120724A: JCMT SCUBA-2 sub-mm observation
  74. GRB 120724A: Swift/UVOT Detection of the Optical Afterglow
  75. GRB 120724A: Gemini-N tentative redshift
  76. GRB 120722A: Swift/UVOT Upper Limits
  77. GRB 120722A: VLT/X-shooter redshift of the host galaxy
  78. GRB 120722A: GROND detection of the afterglow
  79. GRB 120722A: 1.5m OSN I-band observations
  80. GRB 120722A: Xinglong TNT optical afterglow candidate
  81. GRB 120716A: EVLA Detection
  82. GRB 120716A: Swift-XRT detection
  83. GRB 120716A: Redshift confirmation from VLT/X-shooter
  84. VLT/FORS2 redshift of GRB120716A
  85. GRB 120716A: GROND confirmation of the optical/NIR afterglow
  86. GRB 120716A: Optical decay from NOT
  87. GRB 120716A: Candidate Optical Afterglow from PTF
  88. GRB 120711A: ATCA 34GHz final observations (upper limit)
  89. GRB 120714B: Swift/UVOT Detection
  90. GRB120714A: Swift/UVOT upper limits
  91. GRB 120714A: GROND upper limits
  92. GRB 120714B: GROND confirmation of fading afterglow
  93. GRB 120714B: Redshift from VLT/X-shooter
  94. GRB 120624B: VLA Observations
  95. GRB 120711A: INTEGRAL/SPI observations
  96. GRB 120714A: Swift-XRT observations
  97. GRB 120711A: ATCA 34GHz further observations (upper limit)
  98. GRB 120712A: Swift/UVOT Detection
  99. GRB 120712A: VLT/Xshooter redshift
  100. GRB 120712A Gemini-S redshift

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