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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"
  1. GRB 170825A: AGILE/MCAL Detection
  2. LIGO/Virgo G298936 : MAXI/GSC observations
  3. LIGO/Virgo G298048: MASTER Global-Net early optical observations and the Possible KiloNova SSS17a in NGC 4993 photometry and merging rate
  4. LIGO/Virgo G298048: Pierre Auger Observatory neutrino follow-up
  5. LIGO/Virgo G298048: Subaru HSC z-band imaging of the OT candidate SSS17a
  6. LIGO/Virgo G298048: Near-infrared fading from Gemini-South
  7. LIGO/Virgo G298048: HAWC follow-up
  8. LIGO/Virgo G298048: Gemini-South Imaging and Spectroscopy
  9. LIGO/Virgo G298048: MUSE Integral Field Observations
  10. LIGO/Virgo G298048: LWA radio observations
  11. Konus-Wind observation of GRB 170822A
  12. GRB 170823A: Swift-BAT refined analysis
  13. LIGO/VIRGO G298048: AAT/AAO spectroscopic observations of the GW counterpart candidate SSS17a/DLT17ck
  14. LIGO/Virgo G298048: LOFAR follow-up
  15. LIGO/Virgo G298936: GWFUNC/CNEOST optical observations and an optical transient
  16. LIGO/Virgo G298048: H.E.S.S. very-high energy gamma-ray follow-up
  17. LIGO/Virgo G297595: H.E.S.S. very-high energy gamma-ray follow-up
  18. LIGO/Virgo G298048: INTEGRAL pointed follow-up observations
  19. LIGO/Virgo G298048: Results of the ASKAP search for fast radio bursts
  20. LIGO/Virgo G298048: ATCA follow-up of SSS17a in NGC 4993
  21. LIGO/Virgo G298048: Properties of NGC 4993
  22. LIGO/Virgo G298389: CALET Observations
  23. LIGO/Virgo G298936 : Fermi-LAT search for a high-energy gamma-ray counterpart
  24. GRB 170823A: Swift detection of a burst
  25. LIGO/Virgo G298936: Swift/BAT data search
  26. LIGO/Virgo G298048: Continued VLA monitoring at 6 GHz
  27. LIGO/VIRGO G298936: Fermi GBM Observations
  28. LIGO/Virgo G298936: AGILE GRID observations
  29. LIGO/Virgo G298936: Updated localization from gravitational-wave data
  30. LIGO/Virgo G298936: AGILE MCAL observations
  31. LIGO/Virgo G298936 ANTARES search
  32. LIGO/Virgo G298936: INTEGRAL was inactive at the time of the event
  33. LIGO/Virgo G298936: IceCube neutrino observations
  34. LIGO/Virgo G298936: Identification of a GW Binary Black Hole Candidate
  35. GRB 170822A: RATIR Optical and NIR Observations
  36. GRB 170822A: AbAO optical upper limit
  37. LIGO/Virgo G298048: ESO/VLT optical observations
  38. GRB 170822A: MITSuME Akeno Optical Observation
  39. GRB 170822A: Swift-BAT refined analysis
  40. LIGO/VIRGO G298048: VLA/JAGWAR observations of the CLU galaxies
  41. GRB 170822A: Swift/UVOT Upper Limits
  42. LIGO/Virgo G298048: Chandra X-ray observations
  43. GRB 170822A: Swift-XRT refined Analysis
  44. LIGO/Virgo G298389 : MAXI/GSC observations
  45. LIGO/Virgo G298048: Global properties and star-formation rate of NGC 4993
  46. LIGO/Virgo G298048: observations of optical counterpart candidate with CHILESCOPE observatory
  47. GRB 170822A: Enhanced Swift-XRT position
  48. GRB 170822A:BOOTES-5/JGT optical afterglow candidate
  49. LIGO/Virgo G298048: CALET Observations
  50. GRB 170822A: Swift detection of a burst
  51. LIGO/Virgo G298048: ASKAP observations of SSS17a and NGC 4993 at 1.345 GHz
  52. LIGO/Virgo G298048: Gemini-South Near-Infrared Spectroscopy
  53. LIGO/Virgo G298048: MWA Observations of Error Region
  54. LIGO/Virgo G298048: VLA observation at 15 GHz
  55. LIGO/Virgo G298048: observations of optical counterpart candidate with CHILESCOPE observatory
  56. LIGO/Virgo G298048: TOROS Spectra observation with CASLEO
  57. LIGO/Virgo G298048: Pan-STARRS izy photometry of SSS17a/DLT17ck
  58. LIGO/Virgo G298048: Continued monitoring of the optical counterpart candidate
  59. LIGO/Virgo G298048 ANTARES search (2)
  60. Konus-Wind observation of GRB 170816A
  61. LIGO/Virgo G298048: Correction to ATCA 8.5 GHz observations
  62. LIGO/Virgo G298048: ATCA 8.5 GHz observations of galaxies in the localisation volume
  63. LIGO/Virgo G298048: Zadko observations of the OT candidate SSS17a/DLT17ck
  64. LIGO/Virgo G298048: NuSTAR limits on X-ray emission
  65. LIGO/Virgo G298048: ASKAP follow up
  66. LIGO/Virgo G298048: optical observations with BOOTES-5 at San Pedro Mártir
  67. LIGO/Virgo G298048: Kanata/HONIR NIR photometry of the possible counterpart of G298048
  68. LIGO/Virgo G298389: Swift/BAT data search
  69. LIGO/Virgo G298048: On the kick velocity and age of the binary Neutron Stars Progenitor
  70. LIGO/Virgo G298048: TOROS optical counterpart search (continuation)
  71. LIGO/Virgo G298048: TOROS optical counterpart search
  72. LIGO/Virgo G298048: optical observations of CHILESCOPE observatory
  73. LIGO/Virgo G298048: Pan-STARRS izy photometry monitoring of SSS17a/DLT17ck
  74. LIGO/Virgo G298389 : Fermi-LAT search for a high-energy gamma-ray counterpart
  75. GRB 170816A CALET Gamma-Ray Burst Monitor detection
  76. LIGO/Virgo G298048: VLA observation at 6 GHz
  77. LIGO/Virgo G298048: Continued VLA observations
  78. LIGO/Virgo G298048: Possible X-ray detection with Swift
  79. LIGO/Virgo G298389: INTEGRAL search for a prompt gamma-ray counterpart
  80. LIGO/VIRGO G298048: SALT optical spectra of the candidate optical/NIR counterpart of the gravitational wave G298048 in NGC4993.
  81. LIGO/Virgo G298048: Etelman Observatory observation of the potential LIGO EM counterpart SSS17a
  82. LIGO/Virgo G298048: GROND observations of candidate optical counterpart
  83. LIGO/Virgo G298389: Fermi GBM Upper Limits
  84. LIGO/Virgo G298048: Continued observation for DLT17ck
  85. LIGO/Virgo G298389: AGILE MCAL observations
  86. LIGO/Virgo G298389: AGILE GRID observations
  87. LIGO/Virgo G298048: GMRT Follow-up of SSS17a
  88. LIGO/Virgo G298389: IceCube neutrino observations
  89. LIGO/Virgo G298389 ANTARES search
  90. LIGO/Virgo G298389: Identification of a GW Burst Candidate
  91. LIGO/Virgo G298048: La Silla - QUEST archival non-detections of of LIGO EM counterpart SSS17a
  92. LIGO/VIRGO G298048: INAF VST-ESO PARANAL observations
  93. LIGO/Virgo G298048: KMTNet and other optical follow-up observations
  94. LIGO/Virgo G298048: further REM optical/NIR observations of candidate in NGC 4993
  95. LIGO/Virgo G298048: Subaru HSC z-band photometry confirms the fading nature of SSS17a
  96. LIGO/Virgo G298048: VLT linear polarimetry
  97. GRB 170817B: Insight-HXMT observation
  98. LIGO/Virgo G298048: GRAWITA VLT/X-shooter observations
  99. LIGO/Virgo G298048: NOT near-infrared observations of SSS17a
  100. LIGO/Virgo G298048: Further Pan-STARRS izy photometry confirms rapid fading of SSS17a/DLT17ck in i and z bands

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