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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"

879 results found.

  1. ICSP VLF observation of the signatures of SGR/AXP 1E1547.0-5408 bursts
  2. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  3. IBAS Alert N. 5442 is not a GRB
  4. Suzaku ToO Observation of AXP 1E 1547.0-5408
  5. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  6. AXP 1E1547.0-5408: RHESSI observations up to 400 keV
  7. Konus-Wind detection of very bright SGR-like burst on January 25, 2009
  8. Trigger 340734: Swift detection of a possible short burst
  9. AXP 1E1547.0-5408 activity with SGR bursts
  10. GRB 090111: Swift UVOT Upper Limits
  11. GRB 081222: Swift XRT refined analysis
  12. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  13. SGR 1806-20: Fermi GBM detection.
  14. SGR 1806-20: Fermi GBM detection
  15. SGR 0501+4516: optical observations in August
  16. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  17. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  18. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  19. Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
  20. GRB 081024: Swift detection of a burst
  21. INTEGRAL ToO observation of the AXP 1E 1547.0-5408
  22. AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
  23. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  24. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  25. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  26. Trigger 330353: Swift detection of a Galactic short soft burst
  27. SGR 0501+4516: preliminary results of the Suzaku ToO observation
  28. SGR 0501+4516 : P200 i-band observations
  29. SGR J0501+4516: radio pulsar searches with GBT and WSRT
  30. Recent VLA non-detection of SGR 0501+4516
  31. SGR 0501+4516: Spin Down Rate and Inferred Dipole Magnetic Field
  32. SGR 0501+4516: preliminary results of the first XMM-Newton observation
  33. nIR observations of SGR 0501+4516
  34. INTEGRAL ToO observation of SGR0501+4516
  35. SGR 0501+4516: Confirmation of the NIR counterpart
  36. SGR 0501+4516: Detection of possible optical counterpart
  37. SGR 0501+4516: WHT observations of the possible near-infrared counterpart
  38. VLA non-detection of SGR 0501+4516
  39. Radio Detection of SGR 0501+4516: Retraction
  40. SGR 0501+4516: XMM-Newton monitoring schedule
  41. SGR 0501+4516: Decline in Activity
  42. SGR 0501+4516: Proximity to supernova remnant HB9
  43. Enhanced Swift-XRT position of SGR 0501+4516
  44. SGR 0501+4516: GMRT Radio Observation at 618 MHz
  45. SGR 0501+4516: Swift XRT measure of the spin period
  46. SGR 0501+4516: Fermi GBM (formerly GLAST Burst Monitor) observations of three exceptionally intense outbursts
  47. Soft Gamma Repeater SGR 0501+4516: GBM Detection of multiple bursts
  48. Suzaku ToO Observation of SGR 0501+4516
  49. SGR 0501+4516: radio pulsar searches with GBT and WSRT
  50. Konus-Wind observations of new SGR 0501+4516
  51. INTEGRAL ToO Observation of SGR0501+4516
  52. Radio Detection of SGR 0501+4516
  53. SGR 0501+4516: MDM Optical Observations
  54. SGR 0501+4516: Astrotel-Caucasus optical observations
  55. SGR 0501+4516: UKIRT detection of possible infra-red counterpart
  56. SGR 0501+4516: WSRT Radio Observations
  57. Trigger 321551: Continued Large Flaring of SGR 0501+4516
  58. SGR 0501+4516: optical observations
  59. Swift Trigger 321481: A Large Flare from SGR 0501+4516
  60. SGR 0501+4516: Swift-BAT refined analysis of the 3 discovery events
  61. Discovery of the Spin Period of the New Soft Gamma Repeater SGR 0501+4516
  62. GRB080818B: GLAST Burst Monitor detection
  63. Third event from SGR 0501+4516
  64. GRB 080822 (SGR 0501+4516): archival optical observations
  65. New Soft Gamma Repeater 0501+4516 was GRB 080822
  66. SGR 1627-41: Chandra/RXTE/Swift Observations Scheduled
  67. Konus-Wind observation of reactivation of SGR 1627-41
  68. Reactivation of SGR 1627-41
  69. GRB 080520: Swift XRT Refined Analysis
  70. GRB 080205: Swift XRT refined analysis
  71. GRB 080121: Upper limit on X-ray afterglow
  72. GRB080120: Swift XRT position
  73. Disregard the "GRB 071126" position
  74. Swift XRT follow-up observations of GRB071008
  75. GRB 071017: a SHORT GRB detected by INTEGRAL
  76. GRB 071003: XRT refined analysis
  77. INTEGRAL ToO observations of SGR1806-20
  78. SGR1806-20: Swift-BAT detection of enhanced activity
  79. Intense burst from SGR 1806-20 detected on September 7
  80. Swift detection of a outburst from SAX J1810.8-2609
  81. AGILE-ACS position for the SGR 1806-20 July 27 burst
  82. Intense burst from SGR 1806-20 detected on July 27
  83. GRB 070729: Swift-XRT refined analysis
  84. GRB 070520B: Swift-XRT refined analysis
  85. GRB 070520A: Swift-XRT refined analysis
  86. Suzaku ToO observation of SGR 1806-20
  87. INTEGRAL ToO Observation of SGR1806-20
  88. long burst from SGR 1806-20 detected on March 26
  89. GRB 070201: clarification on localization and Konus-Wind spectra
  90. IPN localization of very intense short GRB 070201
  91. GRB070107: Swift/XRT refined analysis
  92. GRB061222B: Swift-XRT Refined Analysis
  93. GRB061025: Swift XRT refined analysis
  94. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  95. GRB 060729: An update on the late-time Swift observations
  96. GRB 060926: Swift XRT refined analysis
  97. Two bright bursts from SGR 1806-20 detected with IBAS
  98. Image of the dust-scattering halo around SGR 1806-20
  99. Second VLA limit on new radio point source in SGR 1806-20
  100. A dust-scattering halo detected around SGR 1806-20

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