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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"

20959 results found.

  1. GRB 160104A: Spectroscopic observations from 10.4m GTC
  2. GRB 160104A: Mini-GWAC upper limit during prompt emission phase
  3. GRB 160104A: GWAC upper limit during prompt emission phase
  4. GRB 160104A: MITSuME Okayama Ks-band upper-limit
  5. LIGO/Virgo G211117: Fermi/LAT observations
  6. LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates
  7. LIGO/Virgo G211117: Gemini classification of 7 Pan-STARRS transients
  8. LIGO/Virgo G211117: LOFAR follow-up
  9. GRB 160102A: Swift-XRT observations
  10. LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates
  11. LIGO/Virgo G211117: PESSTO classification of Pan-STARRS transients
  12. LIGO/Virgo G211117: MASTER OTs 26.XII.2015 - 01.I.2016
  13. LIGO/Virgo G211117: CSS/CRTS observations on 29/30 Dec 2015 UT
  14. GRB 160102A: Tiled Swift observations
  15. LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28 - 30
  16. GRB 160101A: Swift/UVOT Detection
  17. GRB 160101A: Swift-XRT afterglow detection
  18. GRB 160101A: Tiled Swift observations
  19. LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates
  20. LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
  21. LIGO/Virgo G211117: MAXI/GSC observations
  22. MASTER-NET observations of V404Cyg Swift Trigger 668877
  23. LIGO/Virgo G211117: Liverpool Telescope followup of EM candidates
  24. LIGO/Virgo G211117: VLA follow-up
  25. Trigger 668877: Swift detection of V 404 Cyg
  26. LIGO/Virgo G211117: MAGIC very-high energy gamma-ray observations
  27. LIGO/Virgo G211117: INAF TNG follow-up of MASTER OT J020906.21+013800.1
  28. LIGO/Virgo G211117: OAO-WFC NIR follow-up observations
  29. LIGO/Virgo G211117: SkyMapper observations and transient candidate
  30. V404Cyg Swift Trigger 668097: CrAO RT-22 radio observations
  31. LIGO/Virgo G211117: MASTER Observations of the 3 iPTF candidates
  32. V404Cyg Swift Trigger 668097: AbAO optical observations
  33. GRB 151228B: Swift/UVOT Detection
  34. LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
  35. LIGO/Virgo G211117: List of near-term future observation regions by Project Mini-GWAC of SVOM
  36. LIGO/Virgo G211117: iPTF Optical Transient Candidates
  37. LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28, 29
  38. GRB 151229A: Swift/UVOT observations
  39. LIGO/Virgo G211117: Further Swift-XRT sources
  40. GRB 151228A: T60 observations
  41. LIGO/Virgo G211117: DESGW program observations with DECam
  42. LIGO/Virgo G211117: Optical NIR observation with Kanata telescope
  43. LIGO/Virgo G211117: Fermi GBM Observations
  44. LIGO/Virgo G211117: Optical follow-up with Kanata telescope
  45. LIGO/Virgo G211117: MASTER Observations and Inspection + OT
  46. LIGO/Virgo G211117: Pan-STARRS1 observations 2015-12-28
  47. LIGO/Virgo G211117: INAF VST-ESO PARANAL observations
  48. LIGO/Virgo G211117: Further Swift-XRT sources
  49. LIGO/Virgo G211117: Swift-XRT sources
  50. LIGO/Virgo G211117: SWASP optical observations
  51. LIGO/Virgo G211117: MASTER possible OT detection at the begining of inspection
  52. V404Cyg Swift Trigger 668097: TSHAO optical observations
  53. V404Cyg Swift Trigger 668097: MASTER-Tunka optical wake up detection
  54. GRB 151215A: TSHAO optical observations
  55. GRB151215A: Continued P60 Observations
  56. GRB151215A: Early optical light curve from pt5m, La Palma
  57. GRB151215A: Swift/UVOT detection
  58. GRB 151215A: GROND Detection of the Optical/NIR Afterglow
  59. GRB151215A: P60 Optical Afterglow Candidate
  60. LIGO/Virgo G184098: LOFAR follow-up
  61. GRB151212A: Swift/UVOT observations
  62. GRB 151212A: GROND Optical Afterglow Candidate
  63. GRB 151212A: Swift-XRT afterglow detection
  64. GRB 151212A: Tiled Swift observations
  65. GRB 151210A: Swift/UVOT Upper Limits
  66. GRB 151210A: GROND Afterglow Confirmation
  67. GRB 151210A: Optical afterglow candidate from LCOGT-Cerro Tololo
  68. GRB 151205C: Optical follow-up observations at Kiso
  69. GRB 151205B: Deep GROND Upper limits
  70. GRB 151205B: further Swift-XRT observations
  71. GRB 151205C: Swift-XRT observations
  72. GRB 151205C: Tiled Swift observations
  73. GRB 151205B: MASTER-NET early optical observations
  74. GRB 151205A: Garching Telescope Upper Limit
  75. GRB151205B: Initial UVOT observations
  76. GRB 151205B: Swift-XRT observations
  77. GRB 151205A: Swift/UVOT Upper Limits
  78. LIGO/Virgo G184098: Results of of 2nd epoch of ASKAP follow-up
  79. GRB 151122A: Further Swift-XRT observations, no afterglow detected.
  80. GRB 151127A: Swift/UVOT Upper Limits
  81. GRB 151127A: GROND K-band upper limit
  82. GRB 151127A: LCOGT-SSO optical upper limits
  83. GRB 151122A: Swift/UVOT Observations
  84. GRB 151122A: Swift-XRT observations
  85. GRB 151122A: Swift ToO observations
  86. GRB 151027A: Maidanak optical observations
  87. GRB 151120A: Swift-XRT afterglow detection
  88. GRB 151120A: Swift ToO observations
  89. GRB 151120A: GROND optical/NIR afterglow
  90. LIGO/Virgo G194575: Fermi GBM Observations
  91. 610 MHz detection of GRB 151027A with the GMRT
  92. GRB 151118A: Early optical limit from pt5m, La Palma
  93. GRB 151027A: SAO RAS and Mt. Terskol observations
  94. GRB 151118A: Swift/UVOT Upper Limits
  95. GRB GRB 151118A: MASTER-NET optical observations
  96. GRB 151118A: Optical observations from OSN
  97. GRB151027A; Optical observations
  98. GMRT radio detection of GRB 151027A
  99. GRB 151114A: GROND Detection of the Optical/NIR Afterglow Candidate
  100. GRB 151112A: GROND photometric redshift and i'-band prediction

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