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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"

20558 results found.

  1. GRB 171027A: Swift/UVOT Upper Limits
  2. GRB 171027A: VLT optical upper limits
  3. GRB 171027A: LCO 1-m telescope observations
  4. GROND observations of GRB 171027A: correction
  5. GRB 171027A: RATIR Detection of a NIR Afterglow Candidate
  6. GROND observations of GRB 171027A
  7. GRB 171027A: MASTER-OAFA (Argentina) early prompt optical observations
  8. Swift trigger 781740: Further analysis from Swift and Fermi/GBM
  9. Swift Trigger 781740 is not a burst
  10. Fermi GBM Observations of IceCube-171015A
  11. GRB 171020A: Continued RATIR Optical and NIR Observation
  12. GRB 171020A: TAROT Calern observatory optical observations
  13. GRB 171020A: Swift/UVOT Upper Limits
  14. GRB 171020A: RATIR Optical and NIR Observations
  15. GRB 171020A: LT observations
  16. GRB 171020A: NOT optical afterglow detection
  17. Swift Trigger on AXP CXOU J164710.2-455216/PSR J1647-4552
  18. GRB 171010B: Swift-XRT afterglow detection
  19. Trigger 779762: Swift detection of Vela X-1
  20. Swift trigger 779171 is probably a noise fluctuation
  21. GRB 171010A: VLA Observations
  22. GRB 171010A: VLA Detection
  23. GRB 171010A: A detection of a radio source by AMI
  24. GRB 171010A : Optical observations from HCT
  25. GRB 171010A: RATIR Optical and NIR Observations
  26. BAT trigger 778435 is not a GRB.
  27. GRB 171010B: Swift-XRT observations
  28. GRB 171013A: TAROT Calern observatory optical observations
  29. GRB 171010A: Swift/UVOT Detection
  30. GRB 171010A: ePESSTO NTT spectroscopic redshift
  31. GRB 171010A: NOT optical observations
  32. GRB 171010B: Swift ToO observations
  33. GRB 171011A: TAROT Calern observatory optical observations
  34. GRB 171011A: MASTER-SAAO optical observations
  35. GRB 171010A: LCO 1m telescope observations
  36. GRB 171010A: Swift-XRT afterglow detection
  37. GRB 171010A: optical observations
  38. GRB 171010A: OT, spectrum, and possible host galaxy
  39. GRB 171010A: Swift ToO observations
  40. GRB 171007A: Swift/UVOT Upper Limits
  41. LIGO/Virgo G298048: Mid-Infrared Spitzer/IRAC Observations at 3.6 and 4.5 microns
  42. GRB 171007A: RATIR Optical and NIR Observations
  43. LIGO/Virgo G298048: LWA radio observations
  44. GRB 171004A: Swift/UVOT Upper Limits
  45. LIGO/Virgo G299232: SWASP optical imaging coverage
  46. GRB 171004A: RATIR Optical and NIR Observations
  47. GRB 170710A: LCO Observations
  48. LIGO/Virgo G299232: MAGIC Cherenkov Telescopes observations
  49. Swift Trigger 775946 is a Galactic transient, not GRB 171003
  50. LIGO/Virgo G299232: LOFAR follow-up
  51. GRB 171003A: LT early optical observations
  52. GRB 171003A: Swift detection of a burst or a Galactic Transient
  53. GRB 171001A: RATIR Optical and NIR Observations
  54. GRB 171001A: Nanshan-0.36m optical afterglow detections
  55. GRB 171001A: Swift/UVOT Detection
  56. GRB 171001A: IRSF Observation
  57. GRB 170921A: 15 GHz upper limits from AMI
  58. GRB 170903A: 15 GHz upper limits from AMI
  59. GRB 170906C: 15 GHz upper limits from AMI
  60. GRB 170823A: 15 GHz upper limits from AMI
  61. GRB 170822A: 15 GHz upper limits from AMI
  62. LIGO/VIRGO G299232: AMI-LA Observations of the optical transient Swift J014008.5+343403.6
  63. 3.6m Devasthal Optical Telescope observations of GRB 170428A
  64. Further Swift-XRT observations of IceCube 170922A
  65. LIGO/Virgo G298048: Record of all e-MERLIN results to date on SSS17a
  66. LIGO/Virgo G298048: Further European VLBI Network (EVN) observations of SSS17a
  67. LIGO/Virgo G299232/GW170825: serendipitous XMM-Newton slew observations
  68. LIGO/Virgo G298936/GW170823: serendipitous XMM-Newton slew observations
  69. LIGO/VIRGO G298048: VLA detection of the radio counterpart at 6 GHz
  70. LIGO/VIRGO G298048: Further MeerKAT observations of SSS17a
  71. LIGO/Virgo G298048: Summary of Pi of the Sky observations
  72. IceCube-170922A: Swift-XRT observations
  73. LIGO/VIRGO G298048: Latest 3 GHz Detection of Radio Counterpart to SSS17a
  74. LIGO/Virgo G298048: Limits from further FRB searches of SSS17a
  75. LIGO/Virgo G298048: MWA Observations of Error Region
  76. LIGO/Virgo G298048: Effelsberg 100-m Radio Telescope observations of SSS17a
  77. GRB 170921A: RATIR Optical Afterglow Detection and NIR Observations
  78. LIGO/Virgo G298048: SRT observations of SSS17a in NGC 4993
  79. GRB 170921A: Swift/UVOT Upper Limits
  80. GRB 170921A: LCO 2m telescope observations
  81. GRB 170921A: NOT optical observations
  82. LIGO/Virgo G298048: LCO FLOYDS and Gemini Spectroscopy
  83. GRB 170921A: TAROT Calern observatory optical observations
  84. LIGO/Virgo G298048: ATCA monitoring of SSS17a in NGC 4993
  85. LIGO/Virgo G298048: Limits from an FRB search of SSS17a with the Parkes 64m Radio Telescope
  86. LIGO/Virgo G298048: SSS17a photometry of CHILESCOPE observatory
  87. LIGO/Virgo G298048: Milliarcsecond imaging of the NGC 4993 central radio source
  88. LIGO/Virgo G298048: TOROS photometry of SSS17a
  89. LIGO/Virgo G298048: Desert Fireball Network simultaneous optical observations of the SSS17a/DLT17ck.
  90. LIGO/VIRGO G298048: MeerKAT observations of SSS17a
  91. LIGO/Virgo G297595: NIR Observations following GW170814
  92. LIGO/Virgo G298048: Danish Telescope Observations of SSS17a/DLT17ck
  93. LIGO/Virgo G297595: PIRATE observations
  94. LIGO/Virgo G298048: ATLAS pre-discovery limits 601 to 16 days before first detection of SSS17a/DLT17ck
  95. LIGO/Virgo G297595: LSGT observation of nearby galaxies
  96. LIGO/Virgo G298048: AST3-2 observations of SSS17a/DLT17ck from Antarctica
  97. LIGO/Virgo G298048: ATCA monitoring of SSS17a in NGC 4993
  98. GRB 170912B: Swift/UVOT Upper Limits
  99. LIGO/Virgo G299232: Khureltogot observations
  100. GRB 170912A: Swift/UVOT Upper-Limits

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