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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"

2974 results found.

  1. Fermi trigger No 581889628 Global MASTER-Net observations report
  2. GRB 190610A: Swift detection of a short burst
  3. Fermi trigger No 581645543 Global MASTER-Net observations report
  4. IPN Triangulation of GRB 190606A (short)
  5. GRB 190604B: BOOTES-3 early optical limits
  6. GRB 190604B: Swift detection of a burst
  7. LIGO/Virgo S190602aq: No counterpart candidates in HAWC observations
  8. GRB 190530A: Mondy and AbAO optical observations
  9. GRB 190531B: VLT optical upper limit
  10. GRB 190531B: MASTER optical observation
  11. GRB 190531B: Swift-XRT afterglow detection
  12. LIGO/Virgo S190425z: No counterpart candidate in Zadko-GRANDMA observations.
  13. LIGO/Virgo S190521r : Gaia Photometric Alerts transient candidate
  14. LIGO/Virgo S190521r: CNEOST follow-up observations
  15. Fermi GRB190525.67 Global MASTER-Net observations report
  16. Fermi GRB190525.03 Global MASTER-Net observations report
  17. LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC-F30 observations.
  18. LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC observations.
  19. LIGO/Virgo S190519bj Global MASTER-Net observations report
  20. GRB 190519A: Swift-BAT refined analysis
  21. GRB 190519A: Fermi GBM Final Real-time Localization
  22. Fermi GRB190517.81 Global MASTER-Net observations report
  23. LIGO/Virgo S190517h Global MASTER-Net observations report
  24. LIGO/Virgo S190513bm: Swope follow-up observations
  25. LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations
  26. Konus-Wind observation of GRB 190511A
  27. LIGO/Virgo S190510g: Further KMTNet observation of DECam-GROWTH and DESGW candidates
  28. LIGO/Virgo S190512at Global MASTER-Net observations report
  29. Fermi GRB190512.61 Global MASTER-Net observations report
  30. LIGO/Virgo S190510g: DOAO Observation
  31. LIGO/Virgo S190510g: KMTNet observation of DECam-GROWTH and DESGW candidates
  32. LIGO/Virgo S190510g: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  33. LIGO/Virgo S190510g: GRAWITA REM and Loiano optical observations
  34. LIGO/Virgo S190510g: GRAWITA VST-ESO PARANAL optical observations
  35. LIGO/Virgo S190510g: Xinglong/Schmidt Follow-Up Observations
  36. LIGO/Virgo S190510g: Lick/KAIT Follow-Up Observations
  37. LIGO/Virgo S190510g: Lulin Optical Follow-up Observations
  38. LIGO/Virgo S190510g: GRAWITA REM optical observations
  39. Fermi GRB190507.97 Global MASTER-Net observations report
  40. Fermi GRB190507.27 Global MASTER-Net observations report
  41. IceCube-190504A: MASTER optical monitoring analysis
  42. Fermi GRB190506.58 Global MASTER-Net observations report
  43. Fermi GRB190505.05 Global MASTER-Net observations report
  44. Fermi GRB190504.68 Global MASTER-Net observations report
  45. LIGO/Virgo S190503bf Global MASTER-Net observations report
  46. IceCube-190503A: Lick/KAIT Follow-Up Observations
  47. IPN Triangulation of GRB 190501A (long/bright)
  48. LIGO/Virgo S190426c: YAHPT Optical Observation
  49. LIGO/Virgo S190426c: MASTER analysys of GRAWITA transients
  50. LIGO/Virgo S190426c: GRAWITA transients from Asiago Schmidt wide field observations
  51. LIGO/Virgo S190426c: OAJ-GRANDMA observation report
  52. LIGO/Virgo S190425z: MASTER explanation of the nature of an optical flash detected by a Swift as a short flare on a fast-moving WISE brown
  53. LIGO/Virgo S190425z: SVOM/GWAC-F60A observations
  54. LIGO/Virgo S190426c: COATLI Optical Observations of Galaxies
  55. LIGO/Virgo S190426c: Lick/KAIT Follow-Up Observations
  56. LIGO/Virgo S190426c: CNEOST Optical Observations
  57. LIGO/Virgo S190425z: CNEOST Optical Observations
  58. LIGO/Virgo S190425z: BOOTES-5/JGT observations of galaxies
  59. LIGO/Virgo S190425z: Lijiang 2.4-m Telescope Follow-up Observations
  60. LIGO/Virgo S190425z: Additional Pan-STARRS transients in the skymap
  61. LIGO/Virgo S190425z: GRANDMA follow-up observations with Les Makes-T60, AZT-8 and Abastumani-T70
  62. LIGO/Virgo S190425z: Further MMT Follow-Up Observations
  63. Baksan Neutrino Observatory Alert 190405.62: Global MASTER-Net:LIGO/Virgo S190425z: PanSTARR OT AT2019ebq/PS19qp
  64. LIGO/Virgo S190425z: COATLI Observations of Galaxies
  65. LIGO/Virgo S190425z: TAROT-GRANDMA observation report
  66. LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  67. LIGO/Virgo S190425z: KMTNet Observation
  68. LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  69. LIGO/Virgo S190425z: STARE2 simultaneous L-band radio observations
  70. LIGO/Virgo S190425z: OVRO-LWA simultaneous low frequency radio observations of localization region
  71. LIGO/Virgo S190425z: Lulin Follow-Up Observations
  72. LIGO/Virgo S190425z: J-GEM optical follow-up observations with Subaru/FOCAS
  73. LIGO/Virgo S190425z: Xinglong/Schmidt follow-up observations
  74. LIGO/Virgo S190425z: SQUEAN Observation
  75. LIGO/Virgo S190425z: MMT Follow-Up Observations
  76. LIGO/Virgo S190425z: Lick/KAIT Follow-Up Observations
  77. LIGO/Virgo S190421ar: Lick/KAIT Follow-Up Observations
  78. Swift GRB190422.96 Global MASTER-Net observations report
  79. Fermi GRB190422.67 Global MASTER-Net observations report
  80. LIGO/Virgo S190421ar Global MASTER-Net observations report
  81. Konus-Wind observation of GRB 190415A
  82. Fermi GRB190420.98 Global MASTER-Net observations report
  83. Fermi GRB190419.41 Global MASTER-Net observations report
  84. Fermi GRB190417.46 Global MASTER-Net observations report
  85. LIGO/Virgo S190412m: TAROT-GRANDMA observation report.
  86. Fermi GRB190415.17 Global MASTER-Net observations report
  87. LIGO/Virgo S190408an: GRAWITA optical observations of MASTER OT J231043.63+470956.4
  88. GRB 190404C: MITSuME Akeno and Okayama optical upper limits
  89. GRB 140404C: MAXI/GSC detection
  90. GRB 190330A: MITSuME Akeno and Okayama optical upper limits
  91. Trigger 896552: Swift detection of PSR B1055-52
  92. Swift Trigger 895479: Detection of GRO J2058+42
  93. GRB 190326A: Swift-BAT refined analysis - a soft-short GRB or an SGR
  94. Swift Trigger 895257: Detection of GRO J2058+42 in outburst
  95. Fermi Trigger 575251142 / GRB 190325999 / GRB 190325A: BALROG localization
  96. SWIFT GRB190323.85 Global MASTER-Net observations report
  97. Swift Trigger 894268: Detection of GRO J2058+42 in outburst
  98. GRB 190220A: Swift-BAT refined analysis
  99. GRB 190219A: NEXT-0.6m optical upper limit
  100. GRB190219A: MASTER Global Robotic Net optical observation

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