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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"

5814 results found.

  1. LIGO/Virgo S190901ap : No significant candidates found in GRANDMA citizen science observations
  2. GRB 190901A: AstroSat CZTI detection
  3. ZTF19abvizsw/AT2019pim, search for GRB in SPI-ACS/INTEGRAL data
  4. Fermi trigger No 589561732 Global MASTER-Net observations report
  5. ZTF19abvizsw: AbAO and CrAO photometry
  6. GRB 190829A observations in CrAO, photometry of the SN
  7. Fermi trigger No 589487114 Global MASTER-Net observations report
  8. GRB 190906B: Fermi GBM Final Real-time Localization
  9. Fermi trigger No 589419513 Global MASTER-Net observations report
  10. LIGO/Virgo S190814bv: GRAWITA VST-ESO PARANAL observations and independent transient candidates discovery.
  11. LIGO/Virgo S190901ap : No significant candidates in TAROT-GRANDMA
  12. LIGO/Virgo S190901ap: NOT spectroscopy of AT2019pjv
  13. LIGO/Virgo S190901ap: No counterpart candidates in KAIT observations
  14. LIGO/Virgo S190901ap: Dabancheng-0.5m optical observations of AT2019pjv
  15. GRB 190829A: Liverpool Telescope observations of a slow supernova rise
  16. LIGO/Virgo S190901ap: Additional candidates from the Zwicky Transient Facility
  17. ZTF19abvizsw: COATLI Optical Observations
  18. LIGO/Virgo S190901ap: GOTO optical coverage and detection of AT2019pjv
  19. GRB 190829A: MASTER confirmation of GROND SN
  20. LIGO/Virgo S190901ap : GRAWITA photometric observation of candidate ZTFabvizsw and GCN 25618 revision
  21. LIGO/Virgo S190901ap: MASTER OT J171434.95+280725.6/AT2019pjv detection
  22. LIGO/Virgo S190901ap: no counterpart candidate in the SVOM/GWAC observations
  23. LIGO/Virgo S190901ap: Upper limits from CALET observations.
  24. GRB 190901A: Insight-HXMT/HE detection
  25. LIGO/Virgo S190901ap: Upper limits from Insight-HXMT/HE observations
  26. Fermi trigger No 589263065 Global MASTER-Net observations report
  27. Liverpool Telescope observations of ZTF19abvizsw, a candidate untriggered GRB afterglow
  28. Fermi trigger No 589223981 Global MASTER-Net observations report
  29. LIGO/Virgo S190901ap: Additional observations from the Zwicky Transient Facility
  30. LIGO/Virgo S190901ap: Upper limits from AGILE-GRID observations
  31. LIGO/Virgo S190828l: no counterpart candidate in the SVOM/GWAC observations
  32. LIGO/Virgo S190901ap: No neutrino candidates at Pierre Auger Observatory
  33. LIGO/Virgo S190901ap: No counterpart candidates in Fermi-LAT observations
  34. GRB 190829A: Flattening of optical light curve from continued Liverpool Telescope photometry
  35. LIGO/Virgo S190901ap: no counterpart candidates in the Swift/BAT Observations
  36. LIGO/Virgo S190901ap: Candidates from the Zwicky Transient Facility
  37. LIGO/Virgo S190901ap: No counterpart candidates in AGILE-MCAL observations
  38. LIGO/Virgo S190901ap: Coverage and upper limits from MAXI/GSC observations
  39. LIGO/Virgo S190901ap : no neutrino counterpart candidate in ANTARES search
  40. LIGO/Virgo S190901ap Global MASTER-Net observations report
  41. LIGO/Virgo S190901ap: Identification of a GW compact binary merger candidate
  42. LIGO/Virgo S190901ap: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  43. LIGO/Virgo S190901ap: Upper limits from IceCube neutrino searches
  44. Fermi trigger No 589065714 Global MASTER-Net observations report
  45. Fermi trigger No 589060361 Global MASTER-Net observations report
  46. LIGO/Virgo S190814bv : No significant candidates in TAROT-GRANDMA observations
  47. GRB 190829A: Continued fading inferred from Liverpool Telescope photometry
  48. LIGO/Virgo S190828j : No significant candidates in TAROT-GRANDMA observations
  49. LIGO/Virgo S190828l: No significant candidates in TAROT-GRANDMA observations
  50. GRB 190829A: AGILE-GRID upper limits
  51. Fermi trigger No 588838851 Global MASTER-Net observations report
  52. LIGO/Virgo S190828l: No counterpart candidates in KAIT observations
  53. LIGO/Virgo S190828j: No counterpart candidates in KAIT observations
  54. GRB 190828B: Swift detection of a burst
  55. LIGO/Virgo S190828l: No counterpart candidates in AGILE-MCAL observations
  56. LIGO/Virgo S190828l : no neutrino counterpart candidate in ANTARES search
  57. LIGO/Virgo S190828l: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  58. LIGO/Virgo S190814bv : Magellan IMACS Spectrum of AT2019npv classified as a Type Ib supernova
  59. Fermi trigger No 588398821 Global MASTER-Net observations report
  60. Fermi trigger No 588350802 Global MASTER-Net observations report
  61. LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations
  62. LIGO/Virgo S190814bv: No Optical Counterpart Candidates in Second-Epoch Lick/KAIT Observations
  63. GRB 190821A: Swift detection of a burst
  64. LIGO/Virgo S190814bv: RATIR Optical observations of DECam transients
  65. LIGO/Virgo S190814bv: No candidates from image subtraction in DCT galaxy targeted search
  66. LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
  67. LIGO/Virgo S190814bv: No candidates from DCT galaxy targeted search and observations of DECam-GROWTH candidates
  68. S190814bv: MASTER analysis of DECam-GROWTH candidates
  69. LIGO/Virgo S190814bv : No Counterpart Candidates in Galaxy Targeted Search with Magellan
  70. LIGO/Virgo S190814bv: No Candidates Found in Wide-Field Infrared Search with Palomar Gattini-IR
  71. Fermi trigger No 587505927 Global MASTER-Net observations report
  72. LIGO/Virgo S190814bv: No counterpart candidates in KAIT observations
  73. LIGO/Virgo S190814bv: No counterpart candidates in TOROS observations
  74. LIGO/Virgo S190814bv: no counterpart candidates in Nickel/Direct imaging and non-detections of 2019nmd and 2019nme
  75. LIGO/Virgo S190814bv Global MASTER-Net optical observations
  76. LIGO/Virgo S190814bv : No counterpart candidate in TAROT-GRANDMA observations
  77. LIGO/Virgo S190814bv: Liverpool Telescope imaging of selected galaxies
  78. LIGO/Virgo S190814bv Global MASTER-Net observations report
  79. Fermi trigger No 587392154 Global MASTER-Net observations report
  80. GRB 190813A: Fermi GBM Final Real-time Localization
  81. FRB 190806: MASTER optical observation
  82. Fermi trigger No 586800758 Global MASTER-Net observations report
  83. GRB 190805B: MAXI/GSC detection
  84. GRB 190804B: MAXI/GSC detection
  85. Fermi trigger No 586574612 Global MASTER-Net observations report
  86. LIGO/Virgo S190728q: ZTF Forced Photometry for PS1 and DECam-GROWTH optical candidates, and a note on DECam Photometry from GCN 25215
  87. LIGO/Virgo S190707q: AstroSat CZTI upper limits
  88. LIGO/Virgo S190728q: MITSuME Okayama and Bisei Follow-Up of ZTF19abjethn (AT2019lvs)
  89. LIGO/Virgo S190728q: Optical transients from Pan-STARRS coverage during first 2 nights
  90. LIGO/Virgo S190728q: No counterpart candidates in KAIT observations
  91. LIGO/Virgo S190727h: No counterpart candidates in KAIT observations
  92. LIGO/Virgo S190727h: No counterpart candidates in Fermi-LAT observations
  93. LIGO/Virgo S190720a: No counterpart candidates in Fermi-LAT observations
  94. LIGO/Virgo S190720a: No counterpart candidates in KAIT observations
  95. GRB 190720A: BALROG localization (Fermi Trigger 585326534 / GRB 190720613)
  96. GRB 190720A: Fermi GBM Final Real-time Localization
  97. LIGO/Virgo S190720a: Identification of a GW compact binary merger candidate
  98. LIGO/Virgo S190718y: No counterpart candidates in KAIT observations
  99. Fermi trigger No 585007213 Global MASTER-Net observations report
  100. Fermi trigger No 584804684 Global MASTER-Net observations report

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