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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

16289 results found.

  1. LIGO/Virgo S190814bv: Palomar 200-in spectroscopic redshift and host galaxy properties of ASKAP source AT2019osy
  2. LIGO/Virgo S190814bv: Optical non-detection of radio source AT2019osy from CFHT
  3. Fermi GBM-190816: Eight additional candidates from the Zwicky Transient Facility
  4. LIGO/Virgo S190814bv: DECam-GROWTH detection of an optical counterpart to the radio source AT2019osy
  5. LIGO/Virgo S190814bv: Final list of candidates from the DESGW coadd analysis from the week long search campaign
  6. LIGO/Virgo S190814bv: CFHTphotometryof AT2019npv
  7. LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019npw and AT2019num
  8. LIGO/Virgo S190814bv : Magellan IMACS Spectrum of AT2019npv classified as a Type Ib supernova
  9. LIGO/Virgo S190814bv: SALT optical spectrum of candidate DG19aqbkc
  10. GRB 190824A: Swift/UVOT Upper Limits
  11. LIGO/Virgo S190814bv: No radio counterpart to DG19wxnjc/AT2019npv in ASKAP observations
  12. LIGO/Virgo S190814bv: Keck NIRES spectroscopy of DG19wxnjc/AT2019npv
  13. LIGO/Virgo S190814bv: GROND follow-up observations of AT2019npv
  14. GRB 190821A: Swift/UVOT Upper Limits
  15. GRB 190821A: MASTER VWFC syncronous optical observations
  16. Fermi GBM-190816: MASTER-Net optical observation report
  17. LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations
  18. LIGO/Virgo S190814bv: a potential faint optical counterpart in CFHT imaging
  19. LIGO/Virgo S190814bv: No Optical Counterpart Candidates in Second-Epoch Lick/KAIT Observations
  20. GRB 190821A: T60 Les Makes optical detection of the afterglow
  21. Fermi GBM-190816: Four additional candidates from the Zwicky Transient Facility
  22. LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019noq and AT2019ntn
  23. Fermi GBM-190816: ZTF19abqanpy 10.4m GTC spectroscopy
  24. LIGO/Virgo S190814bv: AT2019nqq 10.4m GTC spectroscopy
  25. LIGO/Virgo S190814bv: RATIR Optical observations of DECam transients
  26. LIGO/Virgo S190814bv: Additional candidates identified in DECam images by the DECam-GROWTH team
  27. LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
  28. LIGO/Virgo S190814bv: SOAR spectroscopy of 2 DESGW candidates
  29. LIGO/Virgo S190814bv: no candidates from optical imaging of selected galaxies at the NOT
  30. LIGO/Virgo S190814bv: New candidates from DECam DESGW difference imaging search
  31. LIGO/Virgo S190814bv: GROND imaging of candidate galaxies
  32. S190814bv: MASTER analysis of DECam-GROWTH candidates
  33. LIGO/Virgo S190814bv: No candidates identified in DECam data by visual inspection
  34. LIGO/Virgo S190814bv: des-gw190814b is a moving object
  35. LIGO/Virgo S190814bv: No Counterparts in DDOTI/OAN Optical Observations
  36. LIGO/Virgo S190814bv: No counterpart candidates in TOROS observations
  37. LIGO/Virgo S190814bv: no counterpart candidates in Keck I MOSFIRE imaging
  38. LIGO/Virgo S190814bv: MeerLICHT coverage second preliminary skymap
  39. LIGO/Virgo S190814bv Global MASTER-Net optical observations
  40. LIGO/Virgo S190814bv: no candidates from GOTO imaging observations
  41. LIGO/Virgo S190814bv: Candidates found in initial DESGW search
  42. LIGO/Virgo S190814bv: Nordic Optical Telescope imaging of selected galaxies
  43. FRB 190806: MASTER optical observation
  44. LIGO/Virgo S190728q: New optical candidates from the DESGW program
  45. LIGO/Virgo S190728q: AT2019lvw 10.4m GTC spectroscopy
  46. LIGO/Virgo S190728q: AT2019lzc 10.4m GTC spectroscopy
  47. GRB 190731A: Swift/UVOT Upper Limits
  48. GRB 190731A: no OT detected by MASTER
  49. IceCube 190730A: No counterpart candidates or blazar activity in GOTO observations
  50. LIGO/Virgo S190728q: AT2019lzt 10.4m GTC spectroscopy
  51. LIGO/Virgo S190728q: ZTF Forced Photometry for PS1 and DECam-GROWTH optical candidates, and a note on DECam Photometry from GCN 25215
  52. IceCube-190730A: MASTER optical observation
  53. LIGO/Virgo S190728q: MITSuME Okayama and Bisei Follow-Up of ZTF19abjethn (AT2019lvs)
  54. LIGO/Virgo S190728q: Optical transients from Pan-STARRS coverage during first 2 nights
  55. LIGO/Virgo S190728q: Optical Counterpart Candidates from DECam-GROWTH
  56. LIGO/Virgo S190728q: ZTF19abjethn TShAO and NUTTelA-TAO optical observations / classification
  57. LIGO/Virgo S190728q: Classification of AT2019lvs/ZTF19abjethn as a CV
  58. LIGO/Virgo S190728q: Update on Sky-Localization and Source-Classification
  59. LIGO/Virgo S190728q: LCO Follow-Up of ZTF19abjethn (AT2019lvs)
  60. LIGO/Virgo S190728q: Pan-STARRS detection of the transient AT2019lvs/ZTF19abjethn 18hrs before S190728q
  61. LIGO/Virgo S190728q: Identification of a Faint Blue Static Source at the Location of ZTF19abjethn
  62. LIGO/Virgo S190728q: Photometric Redshift and Stellar Mass Estimates for the Potential Host Galaxy of Optical Counterpart Candidate ZTF19abjethn
  63. LIGO/Virgo S190728q: Optical Candidate from the Zwicky Transient Facility ZTF19abjethn
  64. LIGO/Virgo S190718y: Classification of AT 2019lqm / Gaia19dcs as a Type Ia Supernova
  65. LIGO/Virgo S190718y: Classification of AT 2019lqn / Gaia19dct as a Type Ia Supernova
  66. GRB 190719C: optical afterglow confirmation
  67. LIGO/Virgo S190720a: No counterpart candidates in CNEOST observations
  68. GRB 190719C: Swift/UVOT Upper Limits
  69. LIGO/Virgo S190718y: No counterpart candidates in CNEOST
  70. GRB 190719C: NOT candidate optical afterglow and host
  71. GRB 190718A: Swift/UVOT Upper Limits
  72. GRB 190718A: FRAM-Auger optical limit
  73. LIGO/Virgo S190707q: No counterpart candidates in the CNEOST
  74. GRB 190706B: Swift/UVOT Detection
  75. GRB 190627A: Discovery Channel Telescope late time observations
  76. GRB 190530A: Observation of the afterglow by NOEMA
  77. GRB 190701A: Swift/UVOT Upper Limits
  78. GRB190701A: No candidates/counterpart in optical follow-up from GROWTH-India Telescope
  79. GRB 190630B: Tien Shan and Koshka Zeiss-1000 optical upper limits
  80. GRB 190630C: ISON-Castelgrande optical upper limit
  81. GRB 190701A: COATLI Optical Observations
  82. GRB 190630C: Swift/UVOT Upper Limits
  83. GRB 190630C: KAIT Optical Upper Limit
  84. GRB 190630B: Swift/UVOT Upper Limits
  85. GRB 190630B: KAIT Optical Afterglow Confirmation
  86. GRB 190627A: VLT/FORS2 spectroscopic redshift
  87. GRB Swift Trigger 912102: KAIT Optical Afterglow Candidate
  88. GRB 190627A: Koshka Zeiss-1000 optical counterpart observations
  89. GRB 190627A : Xinglong 2.16m optical observation
  90. GRB 190627A: GMG observation at the second epoch
  91. GRB 190627A: NOT optical observations
  92. GRB 190627A: Optical imaging by D50 from Ondrejov
  93. GRB 190627A: Optical imaging and spectroscopy from Calar Alto
  94. GRB 190627A: NUTTelA-TAO optical counterpart observations
  95. GRB 190627A: GMG observation
  96. GRB 190627A: MASTER optical counterpart observation
  97. GRB190627A: VIRT Afterglow observation
  98. GRB 190627A: Montarrenti Observatory optical detection
  99. GRB 190627A: NUTTelA-TAO optical observations
  100. Swift trigger 911102: D50 optical limit

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