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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"

3995 results found.

  1. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  2. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  3. GRB 081203A: optical observations
  4. GRB 081206B: Fermi GBM detection
  5. GRB 081206: Fermi GBM detection
  6. GRB081203A: MITSuME optical observation
  7. GRB 081203A: Optical observations of Xinglong TNT telescope
  8. GRB 081204: Swift XRT afterglow candidate
  9. GRB081203A: optical observation
  10. GRB081203: optical observation
  11. GRB 081203: Swift detection of a burst with a bright optical counterpart
  12. Swift Trigger 335971: Swift/UVOT Observations
  13. GRB 081129: Fermi GBM detection
  14. SGR 1806-20: Fermi GBM detection.
  15. GRB 081126: Swift observations continuing
  16. GRB 081119: Fermi GBM detection
  17. SGR 1806-20: Fermi GBM detection
  18. GRB 081104: GROND found no Optical/NIR Afterglow
  19. SGR 0501+4516: optical observations in August
  20. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  21. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  22. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  23. Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
  24. GRB 081024B: BTA deep optical observations
  25. GRB 081028: CrAO optical observations
  26. GRB 081029, SMARTS optical/IR afterglow observations
  27. GRB 081029: Redshift Confirmation from Gemini-South
  28. GRB 081029: REM observations
  29. GRB 081029: UVES/VLT Absorption Redshift
  30. GRB 081028: Swift-XRT refined analysis
  31. GRB 081024: Swift detection of a burst
  32. GRB 081012, Swift-BAT refined analysis
  33. GRB081006: Fermi GBM detection
  34. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  35. GRB 081003B: Swift-XRT upper limit
  36. GRB 081003A: OSN optical observations
  37. GRB 081003A: Swift-XRT Team position and analysis
  38. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  39. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  40. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  41. Trigger 330353: Swift detection of a Galactic short soft burst
  42. GRB 080928: VLT redshift
  43. GRB080928: Gemini-South Absorption Redshift
  44. GRB 080928: GROND DETECTION
  45. GRB 080925: Fermi GBM Detection
  46. SGR 0501+4516: preliminary results of the Suzaku ToO observation
  47. GRB 080915B, Swift-BAT refined analysis
  48. SGR 0501+4516 : P200 i-band observations
  49. GRB 080905C: Fermi GBM detection
  50. SGR J0501+4516: radio pulsar searches with GBT and WSRT
  51. Swift Trigger 324122 is again known source Swift J1842.5-1124
  52. GRB 080906: Swift detection of a burst with optical afterglow
  53. Recent VLA non-detection of SGR 0501+4516
  54. SGR 0501+4516: Spin Down Rate and Inferred Dipole Magnetic Field
  55. SGR 0501+4516: preliminary results of the first XMM-Newton observation
  56. nIR observations of SGR 0501+4516
  57. INTEGRAL ToO observation of SGR0501+4516
  58. SGR 0501+4516: Confirmation of the NIR counterpart
  59. SGR 0501+4516: Detection of possible optical counterpart
  60. SGR 0501+4516: WHT observations of the possible near-infrared counterpart
  61. VLA non-detection of SGR 0501+4516
  62. Radio Detection of SGR 0501+4516: Retraction
  63. SGR 0501+4516: XMM-Newton monitoring schedule
  64. SGR 0501+4516: Decline in Activity
  65. SGR 0501+4516: Proximity to supernova remnant HB9
  66. Enhanced Swift-XRT position of SGR 0501+4516
  67. SGR 0501+4516: GMRT Radio Observation at 618 MHz
  68. SGR 0501+4516: Swift XRT measure of the spin period
  69. SGR 0501+4516: Fermi GBM (formerly GLAST Burst Monitor) observations of three exceptionally intense outbursts
  70. Soft Gamma Repeater SGR 0501+4516: GBM Detection of multiple bursts
  71. Suzaku ToO Observation of SGR 0501+4516
  72. SGR 0501+4516: radio pulsar searches with GBT and WSRT
  73. Konus-Wind observations of new SGR 0501+4516
  74. INTEGRAL ToO Observation of SGR0501+4516
  75. Radio Detection of SGR 0501+4516
  76. SGR 0501+4516: MDM Optical Observations
  77. SGR 0501+4516: Astrotel-Caucasus optical observations
  78. SGR 0501+4516: UKIRT detection of possible infra-red counterpart
  79. SGR 0501+4516: WSRT Radio Observations
  80. Trigger 321551: Continued Large Flaring of SGR 0501+4516
  81. SGR 0501+4516: optical observations
  82. Swift Trigger 321481: A Large Flare from SGR 0501+4516
  83. SGR 0501+4516: Swift-BAT refined analysis of the 3 discovery events
  84. Discovery of the Spin Period of the New Soft Gamma Repeater SGR 0501+4516
  85. Third event from SGR 0501+4516
  86. GRB 080822 (SGR 0501+4516): archival optical observations
  87. New Soft Gamma Repeater 0501+4516 was GRB 080822
  88. GRB 080727B: Late VLT imaging
  89. Trigger 317393: Swift detection of a possible GRB
  90. Trigger 317205: Swift detection of an outburst from XTE J1701-407
  91. GRB 080710, Swift-BAT refined analysis
  92. GRB 080710: Swift detection of a burst
  93. GRB 080707: Swift detection of a burst
  94. GRB 080702B : Burst detected in BAT during Swift slew
  95. GRB 080701: Swift detection of a burst
  96. GRB 080613B: Swift detection of a burst
  97. GRB 080604: Swift detection of a burst with an optical afterglow
  98. SGR 1627-41: Chandra/RXTE/Swift Observations Scheduled
  99. Konus-Wind observation of reactivation of SGR 1627-41
  100. Reactivation of SGR 1627-41

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