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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"

4252 results found.

  1. LIGO/Virgo S190910h: Upper limits from CALET observations.
  2. LIGO/Virgo S190910d and S190910h: No counterpart candidates in KAIT observations
  3. LIGO/Virgo S190910d: AstroSat CZTI upper limits
  4. LIGO/Virgo S190910h: no counterpart candidates in the Swift/BAT observations
  5. LIGO/Virgo S190910h: No counterpart candidates in AGILE-MCAL observations
  6. LIGO/Virgo S190910h : no neutrino counterpart candidate in ANTARES search
  7. LIGO/Virgo S190910h: Coverage and upper limits from MAXI/GSC observations
  8. LIGO/Virgo S190910h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  9. LIGO/Virgo S190910h: Upper limits from IceCube neutrino searches
  10. LIGO/Virgo S190910h: Identification of a GW compact binary merger candidate
  11. Swift Trigger 924641 is an outburst from MAXI J1807+132
  12. LIGO/Virgo S190814bv: ATCA monitoring of ASKAP J005547-270433/AT2019osy
  13. LIGO/Virgo S190901ap: Gaia Photometric Alerts transient candidates
  14. LIGO/Virgo S190901ap : No significant candidates found in GRANDMA citizen science observations
  15. LIGO/Virgo S190814bv: GRAWITA VST-ESO PARANAL observations and independent transient candidates discovery.
  16. LIGO/Virgo S190901ap : No significant candidates in TAROT-GRANDMA
  17. LIGO/Virgo S190901ap: No counterpart candidates in KAIT observations
  18. IPN triangulation of GRB 190903A (short)
  19. LIGO/Virgo S190901ap : GRAWITA photometric observation of candidate ZTFabvizsw and GCN 25618 revision
  20. LIGO/Virgo S190901ap: no counterpart candidate in the SVOM/GWAC observations
  21. Chandra observations of GW170817 ~740-743 days since merger
  22. LIGO/Virgo S190814bv: ATCA observation of ASKAP J005547-270433/AT2019osy
  23. LIGO/Virgo S190901ap Global MASTER-Net observations report
  24. LIGO/Virgo S190901ap: Upper limits from IceCube neutrino searches
  25. LIGO/Virgo S190814bv : No significant candidates in TAROT-GRANDMA observations
  26. LIGO/Virgo S190828j : No significant candidates in TAROT-GRANDMA observations
  27. LIGO/Virgo S190828l: No significant candidates in TAROT-GRANDMA observations
  28. GRB 190829A: Liverpool Telescope observations
  29. GRB 190829A: AGILE-GRID upper limits
  30. GRB 190829A: AGILE ratemeters detection and MCAL upper limits
  31. GRB 190829A: Fermi GBM detection
  32. GRB 190829A: Fermi-LAT Upper Limits
  33. GRB 190829A:: Global MASTER-net optical clear and polarization observations scheduler and some spiculations
  34. LIGO/Virgo S190828l: No counterpart candidates in KAIT observations
  35. GRB 190829A:: MASTER-net bright and decay OT detection
  36. LIGO/Virgo S190829u Global MASTER-Net observations report
  37. GRB 190829A: Dabancheng-0.5m optical afterglow detection
  38. Fermi trigger No 588801358 Global MASTER-Net observations report
  39. GRB 190829A: Fermi GBM Final Real-time Localization
  40. GRB 190828B: VLT/X-shooter optical afterglow candidate
  41. LIGO/Virgo S190828j: No counterpart candidates in KAIT observations
  42. LIGO/Virgo S190828l: Upper limits from Fermi-GBM Observations
  43. LIGO/Virgo S190828l: Upper limits from IceCube neutrino searches
  44. LIGO/Virgo S190828j: Upper limits from IceCube neutrino searches
  45. GRB 190823A: MAXI/GSC detection
  46. Fermi trigger No 588185734 Global MASTER-Net observations report
  47. LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations
  48. LIGO/Virgo S190822c: Upper limits from IceCube neutrino searches
  49. LIGO/Virgo S190814bv: No Optical Counterpart Candidates in Second-Epoch Lick/KAIT Observations
  50. GRB 190821A: Fermi GBM observation
  51. Fermi GBM-190816: Upper limits from IceCube neutrino searches
  52. LIGO/Virgo S190814bv: GRAWITA TNG NIR imaging of AT2019nqq and AT2019nqc
  53. GRB 190816A: Swift-XRT observations
  54. LIGO/Virgo S190814bv: Prioritization of Counterpart Candidates based on a Photometric Redshift Analysis by the DECam-GROWTH Team
  55. LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
  56. LIGO/Virgo S190814bv: GROND imaging of candidate galaxies
  57. SUBJECT: LIGO/Virgo S190814bv: GRAWITA VST-ESO PARANAL observations
  58. S190814bv: MASTER analysis of DECam-GROWTH candidates
  59. LIGO/Virgo S190814bv : No Counterpart Candidates in Galaxy Targeted Search with Magellan
  60. GRB 190813A: Insight-HXMT/HE detection
  61. LIGO/Virgo S190814bv: No counterpart candidates in KAIT observations
  62. LIGO/Virgo S190814bv: no counterpart candidates in Swope imaging
  63. LIGO/Virgo S190814bv: KMTNet observation
  64. LIGO/Virgo S190814bv Global MASTER-Net optical observations
  65. LIGO/Virgo S190814bv : No counterpart candidate in TAROT-GRANDMA observations
  66. IPN triangulation of GRB 190813A (short)
  67. LIGO/Virgo S190814bv: Nordic Optical Telescope imaging of selected galaxies
  68. LIGO/Virgo S190814bv Global MASTER-Net observations report
  69. LIGO/Virgo S190814bv: Upper limits from IceCube neutrino searches
  70. Fermi trigger No 587392154 Global MASTER-Net observations report
  71. GRB 190813A: Fermi GBM Final Real-time Localization
  72. FRB 190806: MASTER optical observation
  73. LIGO/Virgo S190808ae: One Coincident Neutrino Candidate from IceCube Search
  74. LIGO/Virgo S190808ae Global MASTER-Net observations report
  75. IceCube-190730A: Upper limits from a search for additional neutrino events in IceCube
  76. IceCube-190730A - HAWC follow-up
  77. LIGO/Virgo S190728q: No counterpart candidates in H.E.S.S. observations
  78. LIGO/Virgo S190728q: ZTF Forced Photometry for PS1 and DECam-GROWTH optical candidates, and a note on DECam Photometry from GCN 25215
  79. LIGO/Virgo S190707q: AstroSat CZTI upper limits
  80. LIGO/Virgo S190718y: AstroSat CZTI upper limits
  81. LIGO/Virgo S190727h: AstroSat CZTI upper limits
  82. LIGO/Virgo S190720a: AstroSat CZTI upper limits
  83. LIGO/Virgo S190728q: MITSuME Okayama and Bisei Follow-Up of ZTF19abjethn (AT2019lvs)
  84. LIGO/Virgo S190728q: Optical transients from Pan-STARRS coverage during first 2 nights
  85. LIGO/Virgo S190728q: GRAWITA VST-ESO PARANAL observations
  86. LIGO/Virgo s190728q: ePESSTO+ NTT classification of AT2019lvt as a type-Ia SN
  87. LIGO/Virgo S190728q/IceCube neutrino candidate: No counterpart candidates in the Swift-XRT Observations
  88. Fermi Gamma-ray Burst Monitor trigger 190729668/586108936 is not a GRB
  89. S190728q: MASTER multiple previous outbursts detection of ZTF19abjethn=AT2019lvs
  90. LIGO/Virgo S190728q: No counterpart candidates in KAIT observations
  91. LIGO/Virgo S190728q: ZTF19abjethn TShAO and NUTTelA-TAO optical observations / classification
  92. LIGO/Virgo S190728q: Third update on neutrino search with IceCube
  93. LIGO/Virgo S190728q: Classification of AT2019lvs/ZTF19abjethn as a CV
  94. LIGO/Virgo S190728q: Second update on neutrino search with IceCube
  95. LIGO/Virgo S190728q: One neutrino candidate from IceCube search
  96. LIGO/Virgo S190728q: Upper limits from IceCube neutrino searches
  97. LIGO/Virgo S190728q Global MASTER-Net observations report
  98. LIGO/Virgo S190727h: No counterpart candidates in KAIT observations
  99. LIGO/Virgo S190727h: Upper limits from IceCube neutrino searches
  100. Fermi trigger No 585864875 Global MASTER-Net observations report

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